ইন্টারফেস IC
উপশ্রেণী
পণ্য (2,300+)
PCA8575PW,118 - 16-bit I2C I/O Expander TSSOP-24 | NXP
The NXP Semiconductors PCA8575PW,118 is a remote 16-bit I/O expander for the I2C-bus (SCL/SDA), providing a 16-bit quasi-bidirectional parallel port and an interrupt output, housed in a 24-pin TSSOP (4.4 mm body width) surface-mount package and supplied on Digi-Reel. The device supports a supply range of 2.3 V to 5.5 V and operates at an I2C clock frequency up to 400 kHz (Fast-mode), making it drop-in compatible with the wide majority of 3.3 V and 5 V microcontroller I2C peripherals. An I/O expander is a bus-attach peripheral that multiplies a host controller's general-purpose I/O count by adding parallel input/output pins over a serial link. The PCA8575PW,118 belongs to the I2C-bus I/O expander family (I/O expander -> GPIO expander -> parallel I/O port -> interface IC -> integrated circuit). Quasi-bidirectional outputs can be driven low actively by the device or pulled high weakly, which lets a single pin directly sink LED current when configured as an output and still be read as a logic high when the external driver releases the line - useful for keypad scanning and switch-matrix polling. Key features include 16 individually addressable I/O lines, an open-drain interrupt (INT) line that asserts when any input changes state, three hardware address pins (A0/A1/A2) allowing up to eight devices on one bus (128 I/O total), latched outputs with high-current drive capability suitable for direct LED driving, and a low standby current that suits battery-powered designs. The integrated address decoder, input filter, and edge-triggered interrupt block reduce host firmware overhead because the MCU only services the PCA8575PW,118 when an actual port event occurs. Typical applications include adding pushbuttons, keypads, LED indicators, relay drivers, and sensor multiplexing to 8-pin microcontrollers, white-goods and appliance front panels, industrial PLC I/O modules, and PC accessory sideband ports. The 400 kHz Fast-mode I2C clock and 2.3 V to 5.5 V supply let it interface directly with 3.3 V ARM Cortex-M parts and 5 V legacy MCUs without level translation. When designing with this device, place the standard 100 nF VCC bypass within 5 mm of the supply pin and add 10 kohm pull-ups on SDA and SCL - quasi-bidirectional outputs still require external pull-ups to drive logic high reliably. Reserve the INT pin for an MCU edge-triggered input and avoid tying it permanently high; the address pins A0-A2 must be tied to a fixed logic level and not left floating at power-up. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the NXP datasheet alone, including the comparison and pinout data that engineering teams need to qualify a second source.
PCA9306H - Dual I2C/SMBus Voltage-Level Translator | TI
The Texas Instruments PCA9306H is a dual bidirectional I2C-bus and SMBus voltage-level translator with an enable (EN) input, operating from 1.2 V to 3.3 V on VREF1 and 1.8 V to 5.5 V on VREF2, housed in an 8-pin VSSOP (DCT) package. It translates between two voltage domains without a direction pin, making it a compact solution for mixed-voltage I2C and SMBus networks. A voltage-level translator is an interface IC that safely connects digital signals operating at different supply voltages, for example a 1.8 V microcontroller I2C peripheral talking to a 3.3 V or 5 V sensor. Within the signal-chain hierarchy, the PCA9306H belongs to the level-translator family of interface ICs, positioned alongside I2C buffers, repeaters, and multiplexers. Because I2C is an open-drain bus, translation requires a bidirectional pass element rather than a directional buffer - exactly the architecture this device implements. Key features include directionless bidirectional translation, an enable pin that puts both switch channels into a high-impedance state when LOW, and low ON-state resistance of the pass FET, which keeps propagation delay minimal. The wider VREF1 range of the PCA9306H (1.2 V to 3.3 V, versus 1.0 V to 3.6 V or lower-floor variants in the family) makes it suitable for modern low-voltage processors. It supports standard-mode (100 kHz), fast-mode (400 kHz), and fast-mode plus (1 MHz) I2C devices as well as SMBus systems. Architecturally, the device is a pair of N-channel pass transistors with gate drive referenced to EN and the reference supplies. When EN is HIGH, SDA1/SCL1 connect to SDA2/SCL2; pulling either side low through its open-drain pull-up propagates the low to the other side, achieving the gate-threshold offset that produces the voltage shift. Because there is no active buffering, signal integrity is essentially transparent, with propagation delay dominated only by the switch Ron and external pull-up resistors. Typical applications include connecting 1.8 V MCUs to 3.3 V or 5 V sensors and EEPROMs, translating between 3.3 V SMBus hosts and lower-voltage peripherals in servers and networking cards, and interfacing low-voltage FPGA or SoC I2C banks to 5 V legacy buses in industrial control systems. For reliable operation, size the pull-up resistors on both sides of the translator according to the bus speed and bus capacitance; each side must have its own pull-up. Also note the 200 kOhm internal pass-gate resistance behavior at low VREF2 voltages when calculating rise times. This page synthesizes distributor data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
PCA9306USG - Dual I2C/SMBus Voltage-Level Translator | onsemi
The onsemi PCA9306USG is a dual bidirectional I2C-bus and SMBus voltage-level translator with an enable (EN) input, operating from 1.2 V to 3.3 V VREF1 and 1.8 V to 5.5 V VREF2, delivering 1.5 ns typical propagation delay and 3.5 ohm ON-state resistance in an 8-pin VSSOP (US8) package. A voltage-level translator is an interface IC that allows devices operating at different supply voltages - for example a 1.8 V microcontroller and a 5 V sensor - to share the same two-wire bus safely. Within the signal-chain hierarchy, level translators sit in the interface IC family alongside I2C multiplexers, buffers, and repeaters. The PCA9306 belongs to the switch-based (passive) translator class: it uses two N-channel pass transistors per channel rather than active output stages, so the bus is pulled up naturally by the resistors on each rail. Key features include bidirectional voltage translation between 1.2 V and 5 V with no direction pin, support for Standard-mode (100 kbps), Fast-mode (400 kbps), and Fast-mode Plus (1 Mbps) I2C-bus plus SMBus operation, a very low 3.5 ohm ON-state connection that minimizes signal distortion, and an active-high EN input that isolates both buses when the translator is not needed. The 1.5 ns rise/fall propagation characteristic keeps bus timing margin intact even at Fast-mode Plus speeds. The switch architecture means the PCA9306 introduces virtually no drive strength of its own - the 64 mA figure refers to the pass-transistor current handling capability. Because it is a passive switch, lock-up free operation is guaranteed even during bus contention or partial power-down, a known failure mode of active level-shifter designs. Both SDA and SCL channels are identical, so the device handles the full 2-bit I2C bus in a single package. Typical applications include connecting 1.8 V to 3.3 V microcontrollers to 5 V I2C sensors and EEPROMs, level-shifting SMBus rails in server power supplies, battery-powered portable systems where two rail domains must communicate, and mixed-voltage industrial control modules. Design consideration: the EN pin must be driven above the higher VREF2 rail to guarantee the pass gates turn fully on; always provide pull-up resistors on both sides of each channel sized for the respective rail. This page synthesizes distributor cross-reference data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet. Pricing as of 2026-10-19.
PCA9500D - 8-Bit I/O Expander with EEPROM | NXP
NXP Semiconductors PCA9500D is an 8-bit I2C and SMBus I/O port expander with an onboard 2-kbit EEPROM, eight quasi-bidirectional GPIO pins, and operation up to 400 kHz in a 16-pin SOIC package. The expander adds remote status inputs and indicator or control outputs to a host microcontroller while preserving the familiar I2C two-wire interface. An I2C I/O expander is a bus-interface peripheral that converts serial commands from a controller into parallel digital states. In the broader hierarchy, it belongs to interface ICs, digital I/O control, and general-purpose bus peripherals. The PCA9500D combines an 8-bit quasi-bidirectional port with nonvolatile storage, allowing configuration or board-identification data to be retained between power cycles. The three address pins use internal pull-up resistors, allowing up to eight devices to share the common I2C bus. The GPIO address matches the PCF8574, while the EEPROM address matches the PCF8582C-2; consequently, one device appears as two separately addressed functions to the bus master. Its 400 kHz bus rating supports faster communication than the common 100 kHz I2C operating mode. Because each port pin can be assigned independently as an input or output, the device can monitor board-level status and activate indicators such as LEDs. The quasi-bidirectional structure is useful for straightforward bus interfacing, although external pull-ups, electrical-level compatibility, and the intended input or output state must be considered in each design. Typical uses include industrial control boards, removable or backplane cards, LED and switch interfaces, configuration storage, and small embedded systems where GPIO conservation is valuable. The NXP product information specifically identifies hot-insertion support as useful in removable-card and backplane systems. A correct implementation should verify the actual device address, EEPROM map, logic thresholds, pull-up values, and pin functions against the manufacturer datasheet. Do not infer unavailable timing, voltage, temperature, or package dimensions from distributor summaries. For exact design values, consult the linked NXP documentation and validate firmware behavior across power-up, reset, bus faults, and hot-plug conditions.
PCA9500PW - 8-Bit I/O Expander with 2-kbit EEPROM | NXP
The NXP Semiconductors PCA9500PW is an 8-bit I2C-bus and SMBus I/O port expander with an integrated 2-kbit EEPROM in a 16-pin TSSOP package. It operates from 2.5 V to 3.6 V, supports I2C/SMBus communication up to 400 kHz, and provides eight quasi-bidirectional data pins that can be configured independently as inputs or outputs. Three hardware address pins allow as many as eight PCA9500 devices to share one bus. According to the NXP datasheet, the bus master sees the GPIO controller and EEPROM as two separate devices, while the GPIO configuration register is accessed in a manner similar to the PCF8574. An I/O expander is a general-purpose interface IC that increases the number of digital input and output lines available to a host microcontroller without requiring a large parallel GPIO package. In the product hierarchy, the PCA9500 is an I/O expander within the broader category of interface ICs and bus-interface semiconductors. Its quasi-bidirectional ports can read external logic states or drive indicators and other digital loads, making it useful when the main processor has too few general-purpose pins for switches, sensors, LEDs, or control signals. The principal feature is the integrated 2-kbit EEPROM, which adds a small amount of nonvolatile storage for configuration or identification data. The eight GPIO pins support mixed input/output operation, and the three address inputs expand the device count available on a shared I2C or SMBus system. A maximum bus rate of 400 kHz is suitable for standard embedded control buses, while the 2.5 V to 3.6 V supply range targets conventional low-voltage digital systems. The NXP datasheet identifies the PCA9500 as a drop-in replacement for the PCF8574, adding EEPROM functionality to a familiar interface arrangement. The PCA9500 uses the same basic I2C write/read model commonly associated with PCF8574-style devices. Separate device addresses allow the GPIO function and the EEPROM to be accessed independently by the bus master. This separation is useful when the host must read or update stored data without changing live output states. Quasi-bidirectional inputs include an internal pull-up arrangement, making the device convenient for open-drain-style bus signaling and for reading switches or logic states, although external pull-up and drive-strength checks remain important in the final circuit. Typical applications include consolidating LED indicators, reading banks of switches or interlocks, adding configurable control outputs to a microcontroller module, and storing board configuration or asset information in the EEPROM. It can also reduce controller pin count in compact embedded systems while preserving a standard I2C/SMBus connection. Eight address-selectable devices provide substantial expansion without requiring additional host pins. The primary design consideration is to treat the quasi-bidirectional pins as a bidirectional interface rather than as unrestricted push-pull outputs. Check pull-up strength, voltage levels, bus capacitance, and the timing requirements of every connected peripheral. Confirm the PCB land pattern and pin numbering against the manufacturer datasheet before production because the verified product information does not provide a complete public pin table in the supplied material. This page consolidates the verified NXP product information, distributor identification, lifecycle status, bus characteristics, and manufacturer-backed drop-in relationships into an engineering-focused resource. It also distinguishes verified capabilities from parameters that still require confirmation from the full manufacturer datasheet.
PCA9501PW - 8-Bit I/O Expander with 2-kbit EEPROM | NXP
NXP Semiconductors PCA9501PW is an 8-bit I2C and SMBus I/O expander with an integrated 2-kbit EEPROM, eight independently configurable quasi-bidirectional GPIO pins, and support for bus operation up to 400 kHz. The device is supplied in a 20-pin TSSOP package and is designed for 2.5 V to 3.6 V operation. An I/O expander is an interface IC that increases the number of digital input and output pins available to a host microcontroller or embedded processor. The PCA9501 sits within the interface IC hierarchy, where it connects a serial I2C or SMBus controller to LEDs, switches, sensors, and other board-level logic. Its quasi-bidirectional outputs can read external logic states while also driving indicator and control devices. The PCA9501 provides eight GPIO ports, a 2-kbit on-board EEPROM, an interrupt output, and six hardware address inputs. The EEPROM provides nonvolatile storage alongside the GPIO function, allowing the bus master to retain configuration or identification data. Hardware address pins allow up to 64 PCA9501 devices to coexist on one bus when address assignments and bus loading permit. The I2C and SMBus interfaces support operation at frequencies up to 400 kHz. Each GPIO may be configured independently as an input or output, and the input data and output configuration registers follow the familiar programming model of the PCF8574 family. The interrupt pin provides a hardware indication that one or more inputs have changed, reducing the need for continuous polling. Typical uses include LED and relay-control interfaces, configuration and status I/O, telecommunications equipment, networking hardware, base-station systems, and general-purpose expansion for installed boards. The integrated EEPROM also makes the device useful where a small amount of nonvolatile board data must accompany the I/O functions. Designers should account for the electrical behavior of quasi-bidirectional ports, pull up I2C and open-drain interrupt lines as required, and verify logic thresholds before driving external loads. PCB layouts should route the bus cleanly, provide stable bypass capacitance near the supply pins, and maintain adequate spacing between the TSSOP body and adjacent copper features. This page combines the verified NXP product information, manufacturer datasheet, distributor listing, and cross-reference results with practical guidance on pin behavior, bus addressing, interrupt handling, EEPROM use, PCB layout, and drop-in replacement assessment.
PCA9507DP,118 - 2-Wire Bus Extender, 5V, 8-TSSOP | NXP
The NXP PCA9507DP,118 is a 2-wire serial bus extender with integrated 3.3 V to 5 V level shifting, one bidirectional I²C/SMBus channel, and a 400 kHz maximum clock rate, packaged in an 8-pin TSSOP (SOT505-1, DP suffix). It provides bidirectional buffering of SDA and SCL lines while preserving all I²C operating modes (master/slave, multi-master, arbitration) across the level-shift boundary, and it extends the usable bus length up to 18 meters for HDMI DDC, I²C-bus, and SMBus links. The device operates from a 2.7 V to 5.5 V supply and is specified across the -40 °C to +85 °C industrial temperature range. What is an I²C bus extender? An I²C bus extender (also called a bus repeater or accelerator) is a type of interface IC that sits between two segments of a 2-wire serial bus and buffers both SCL (clock) and SDA (data) lines. Its purpose is twofold: to overcome capacitive loading limits that cap I²C bus length, and to translate voltage levels between dissimilar supply domains. The PCA9507 sits in the broader hierarchy of bus interface ICs (interface IC > bus extender > signal buffer/repeater), and is a specialized sibling of the I²C hub/switch family such as the PCA9543A. Key features of the PCA9507DP,118 include: 1 channel of buffered SDA + SCL; support for Standard-mode (100 kHz), Fast-mode (400 kHz), and 3.4 MHz Fast-mode Plus overshoot tolerant operation on the upstream port; 2.7 V to 5.5 V supply range; 218 ns typical propagation delay; and integrated rise-time accelerators that allow designers to drop the bus pull-up resistors while still meeting rise-time budgets on long cables. It also provides hot-swap insertion tolerance so that cards can be plugged into a live backplane without corrupting the bus. The internal architecture uses two N-channel MOSFET pass gates with charge-pump enhancement, plus direction-sensing comparators that automatically configure the channel as upstream or downstream. The upstream (master-side) port tolerates 3.3 V to 5 V, while the downstream port can operate down to 2.7 V, enabling typical 3.3 V-to-5 V HDMI DDC level shifting. The TSSOP-8 footprint makes the part suitable for compact HDMI connector breakouts, display modules, and embedded backplanes. Typical applications include HDMI/DVI Display Data Channel (DDC) level shifters, I²C-bus extension over long cables (up to 18 m) in industrial control panels, SMBus fan and chassis management links, and any board-to-board 2-wire link that must bridge a voltage-level or capacitive-load gap. Because the device preserves arbitration and clock-stretching behavior, it is safe to insert in the middle of an existing multi-master bus. When designing with the PCA9507, remember that the part is a pure bus extender with no pull-ups on either side. Both upstream and downstream segments still require external pull-up resistors sized to the segment capacitance, and the device's quiescent current (typically a few hundred microamps) must be included in the system power budget. For long cables, place the PCA9507 near the connector to keep the high-impedance stub short. This page synthesizes distributor pricing, same-brand and cross-brand drop-in alternatives, and practical design notes for HDMI DDC and long-cable I²C applications - context not collected in the manufacturer datasheet alone.
PCA9509DP,118 - I2C/SMBus Level Translating Repeater | NXP
The NXP PCA9509DP,118 is a level translating I2C-bus/SMBus repeater that enables a processor low-voltage 2-wire serial bus to interface with standard I2C-bus or SMBus I/O, providing bidirectional buffering for both the SDA (data) and SCL (clock) lines at up to 400 kHz in an 8-pin TSSOP (SOT505-1) package. An I2C repeater (also called a bus buffer or redriver) is an interface IC that regenerates the two-wire serial signals so that capacitive loading and voltage-level differences do not limit bus length or device count. Within the interface-IC hierarchy (repeater -> bus buffer -> I2C/SMBus controller -> communication interface IC), repeaters sit between a low-voltage processor side and a higher-voltage peripheral side, keeping rise times and logic thresholds compliant on both segments. Key features include dual-supply level translation, supporting a low-voltage side and a standard 3 V to 5.5 V bus side, and bidirectional buffering that extends the I2C-bus by isolating capacitance on each segment. The device retains all operating modes and features of the I2C-bus system during level shifts, including clock stretching and multi-master arbitration behavior. A typical propagation delay of 109 ns and a low 2 pF input capacitance keep timing margin comfortable even at the 400 kHz fast-mode ceiling, while 5 mA supply current suits power-conscious designs. Technically, the PCA9509 uses open-drain buffer stages with rise-time acceleration so both bus segments retain true open-drain behavior: contention and backplane noise are not passed between segments, and the parts act as fault isolators between a captive processor bus and a larger peripheral bus. Typical applications include extending I2C from an MCU to backplanes and card cages, level-shifting between 1.x V/1.8 V/2.5 V processors and 3.3 V/5 V SMBus peripherals in servers, telecom line cards, and industrial control panels where bus capacitance would otherwise exceed the 400 pF I2C limit. Design-wise, plan pull-up resistor values per segment: each buffered side requires its own pull-ups sized for that segment's total capacitance, since the repeater isolates the two sides electrically. This page synthesizes distributor pricing, availability data, and practical design guidance not found in the manufacturer datasheet, with all parameters traced to NXP and distributor sources as of 2026-10-20.
PCA9510ADP,118 - Hot-Swap I2C/SMBus Buffer | NXP Semiconductors
The NXP Semiconductors PCA9510ADP,118 is a hot-swappable I2C-bus and SMBus bus buffer that allows I/O card insertion into a live backplane without corrupting the data and clock buses. It is supplied in an 8-pin TSSOP (SOP) surface-mount package and buffers one channel of the two-wire serial bus at operating speeds up to 400 kHz. An I2C bus buffer (also called a bus repeater or redriver) is a two-wire interface IC that sits between an I2C or SMBus controller segment and a downstream segment. Within the interface IC hierarchy - serial interface ICs to buffers/repeaters to logic ICs - its role is to isolate bus capacitance, extend the number of devices or cable length a bus can drive, and protect one segment from faults or transients on the other. The defining feature of the PCA9510A is its hot-swap control circuitry. During card insertion, contact bounce and partial power-up can corrupt SDA and SCL lines; the PCA9510A keeps the backplane side disconnected until a stop command or bus idle condition occurs on the backplane without bus contention on the card side. Only then does it make the bidirectional connection, preserving data integrity on the live backplane. Technically, the buffer provides bidirectional buffering with rise-time acceleration on the output sides, allowing larger bus capacitance than a raw I2C port can tolerate. It supports both the standard I2C-bus and the SMBus (System Management Bus) protocol and operates from a single supply, making it a drop-in isolation element between a backplane and a removable I/O card. Typical applications include live-insertion I/O cards in telecom and server backplanes, CompactPCI-style shelves, SMBus segments in power supplies and battery-backed systems, and any hot-pluggable module that must not disturb an operating two-wire bus during insertion or removal. Design consideration: keep the two bus segments physically separated on the PCB and provide adequate pull-up resistors sized for each segment's capacitance; the buffer does not eliminate the need for correct pull-up values on either side. This page synthesizes distributor pricing context, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet, with all electrical data traced to the NXP PCA9510A product data sheet (Rev. 01, 8 September 2005).
PCA9512AD - Hot-Swap I2C/SMBus Buffer, 3.3V-5V | NXP
The NXP PCA9512AD is a level-shifting, hot-swappable I2C-bus and SMBus buffer housed in an 8-pin SOIC package, providing bidirectional buffering for one channel at up to 400 kHz. It integrates two dedicated supply pins (VCC1 and VCC2) that allow independent 3.3 V and 5 V rails to coexist on the same bus while preserving maximum noise margin on each side. The device prevents backplane data/clock corruption during live card insertion by isolating the precharge voltages of the I/O card from the active backplane rails. An I2C/SMBus buffer is a bus repeater/accelerator that isolates two segments of a multi-drop serial bus, supports level translation between mixed-voltage nodes, and optionally accelerates the rising transitions of the SCL/SDA open-drain lines. Buffers sit between a controller and its peripherals, between two bus segments on a backplane, or between a host and removable card. The PCA9512 family belongs to NXP's broader bus-interface category, positioned between simple repeaters (e.g., PCA9507) and full multi-channel hubs (e.g., PCA9548). Hot-swap capability requires a precharge circuit that gently biases SCL/SDA before the card connector mates, avoiding the inrush glitches that would otherwise corrupt bus traffic. Key features of the PCA9512AD include 3 mA sink capability on each side per the I2C specification, support for bus voltages from 2.0 V to 5.5 V on either supply rail, and compatibility with Standard, Fast, and Fast-Plus (400 kHz) I2C modes. The buffer provides offset voltage between the two bus segments to prevent input-to-output latch-up, and it includes rise-time accelerator circuitry that minimizes bus settling time on heavily loaded segments. The 8-SO package is pin-compatible with the PCA9509 and other 8-pin I2C buffers, simplifying PCB layout reuse. The PCA9512AD is built on NXP's sub-micron CMOS process and uses an internal charge pump to drive the gate of the accelerator FETs, ensuring consistent rise-time performance across temperature. The dual-rail architecture allows designers to mix 3.3 V and 5 V devices on the same physical bus without external level translators, and the offset-impedance design prevents bus contention during simultaneous master access. ESD protection exceeds 2 kV HBM on the SCL/SDA pins. Typical applications include hot-swap I/O cards in telecom base stations, ATCA/cPCI backplane signal buffering, server management buses (IPMB, PMBus), and mixed-voltage I2C sensor aggregation. The device is commonly used where 3.3 V MCUs must communicate with 5 V legacy peripherals on the same bus segment. When designing with the PCA9512AD, ensure that VCC1 and VCC2 decoupling capacitors are placed within 2 mm of their respective supply pins. The offset voltage between bus segments must be accounted for in voltage-margin calculations, and live-insertion sequencing must guarantee that the I/O card's SCL/SDA lines reach the buffered idle state before the connector fully mates. Note: per the NXP product page, the PCA9512AD is End-of-Life, so designers should validate last-time-buy opportunities for production runs. This page synthesizes distributor pricing, drop-in alternatives, and practical design guidance that goes beyond the manufacturer datasheet, helping engineers make informed replacement and supply-chain decisions for this EOL part.
PCA9515AD - Dual I2C/SMBus Bus Repeater 400kHz | TI (Tape & Reel)
The Texas Instruments PCA9515AD is a dual bidirectional I2C bus and SMBus repeater (buffer/ReDriver) with 2 channels, supporting up to 400 kHz operation, supplied in an 8-pin SOIC package. It operates from a single 2.3 V to 3.6 V supply and its open-drain I2C I/O pins and enable input are 5.5-V tolerant. An I2C bus repeater is an interface buffer that isolates the capacitance and noise of one segment of an I2C or SMBus from another. Within the signal-chain hierarchy (I2C repeater -> bus buffer -> interface IC -> mixed-signal semiconductor), repeaters let a single controller address far more devices or far longer PCB traces and cables than the ~400 pF bus-capacitance limit would otherwise allow, while keeping rise times compliant. Key features include two identical bidirectional open-drain buffer channels, an active-high repeater-enable input (EN) for power-up isolation and bus segmentation, 5.5-V tolerant I2C I/O and EN for mixed-mode 3.3 V/5 V operation, and lockup-free operation that accommodates the clock-stretching and arbitration behavior of multi-master I2C systems. Technically, the PCA9515A is fabricated in a BiCMOS process. Each buffer uses a rising-edge accelerator and direction-sensing scheme that distinguishes a master-driven LOW from a slave-driven LOW, preventing the input-to-output latch-up that plagued first-generation repeaters. Because both channels are identical, the device can be used as two independent 1-bit repeaters or as a single 2-bit bus switch-style buffer. Typical applications include I2C bus segment isolation in servers and telecom cards, capacitive load expansion on long backplanes and cables, level-tolerant buffering between 3.3 V controllers and 5 V legacy peripherals, and SMBus systems in power-management and battery-pack designs. A key design consideration: the buffer is unidirectional-gain per edge, so it must not be used in loops or back-to-back without careful segmentation; place it where the bus capacitance exceeds roughly 400 pF or when isolating a noisy or fault-prone slave segment. This page adds value beyond the datasheet by synthesizing distributor pricing, verified drop-in alternatives, comparison tables, and practical layout guidance in one place.
PCA9515ADR - Dual I2C/SMBus Bus Repeater 400kHz | TI
The Texas Instruments PCA9515ADR is a dual bidirectional I2C bus and SMBus repeater (buffer/ReDriver) with 2 channels, supporting up to 400 kHz operation, supplied in an 8-pin SOIC package. It operates from a single 2.3 V to 3.6 V supply and its open-drain I2C I/O pins and enable input are 5.5-V tolerant. An I2C bus repeater is an interface buffer that isolates the capacitance and noise of one segment of an I2C or SMBus from another. Within the signal-chain hierarchy (I2C repeater -> bus buffer -> interface IC -> mixed-signal semiconductor), repeaters let a single controller address far more devices or far longer PCB traces and cables than the ~400 pF bus-capacitance limit would otherwise allow, while keeping rise times compliant. Key features include two identical bidirectional open-drain buffer channels, an active-high repeater-enable input (EN) for power-up isolation and bus segmentation, 5.5-V tolerant I2C I/O and EN for mixed-mode 3.3 V/5 V operation, and lockup-free operation that accommodates the clock-stretching and arbitration behavior of multi-master I2C systems. Technically, the PCA9515A is fabricated in a BiCMOS process. Each buffer uses a rising-edge accelerator and direction-sensing scheme that distinguishes a master-driven LOW from a slave-driven LOW, preventing the input-to-output latch-up that plagued first-generation repeaters. Because both channels are identical, the device can be used as two independent 1-bit repeaters or as a single 2-bit bus switch-style buffer. Typical applications include I2C bus segment isolation in servers and telecom cards, capacitive load expansion on long backplanes and cables, level-tolerant buffering between 3.3 V controllers and 5 V legacy peripherals, and SMBus systems in power-management and battery-pack designs. A key design consideration: the buffer is unidirectional-gain per edge, so it must not be used in loops or back-to-back without careful segmentation; place it where the bus capacitance exceeds roughly 400 pF or when isolating a noisy or fault-prone slave segment. This page adds value beyond the datasheet by synthesizing distributor pricing, verified drop-in alternatives, comparison tables, and practical layout guidance in one place.
PCA9515AP - 2-Channel 400kHz I2C Repeater | TI
The Texas Instruments PCA9515AP is a dual-channel bidirectional I2C bus and SMBus repeater operating at up to 400 kHz, supplied in an 8-pin PDIP package. Its two open-drain buffer channels support I2C and SMBus systems, while 5.5 V-tolerant I2C inputs and the enable input permit mixed-mode operation. The device operates from a 2.3 V to 3.6 V supply. An I2C repeater is a bidirectional bus buffer that regenerates a bus signal and separates it into two bus segments. It belongs to the interface IC hierarchy, where I2C and SMBus repeaters support communication among controllers, peripherals, sensors, and embedded processors. Unlike a unidirectional level translator, this device detects and forwards activity in either direction, allowing each side of the bus to retain its own pull-up network. The PCA9515A family provides two identical bidirectional open-drain buffers, an active-high enable input with an internal pull-up, and 5.5 V-tolerant bus and enable inputs. Mixed-mode signal operation is supported, while the open-drain I2C structure maintains wired-AND bus behavior. The verified distributor listing identifies the PCA9515AP as a 400 kHz, two-channel buffer in an 8-pin PDIP package. The repeater is built around BiCMOS interface circuitry intended to preserve the open-drain signaling used by I2C and SMBus. Because both sides communicate bidirectionally, bus capacitance, pull-up strength, rise time, and timing margins must be evaluated separately for each segment. The enable input is particularly useful during system reset because it can isolate a misbehaving peripheral, but its state should not change during an active I2C transfer. Typical uses include isolating a high-capacitance I2C bus, connecting sensors or EEPROMs to a remote bus segment, buffering a processor I2C controller, supporting SMBus power-management hardware, and isolating power domains whose logic levels remain compatible with the repeater. It can also help separate a bus into shorter segments when capacitive loading or timing margins become problematic. The primary design consideration is that the PCA9515AP is not a general-purpose bidirectional level shifter. Its supply range is 2.3 V to 3.6 V, and the enabled repeater must maintain compatible logic levels across both bus segments. External pull-up resistors should be placed close to each bus segment, with values selected from the actual capacitance and required rise time rather than copied blindly. This page consolidates verified distributor specifications, the official manufacturer datasheet, package details, application guidance, and honest replacement analysis. It also distinguishes verified drop-in interchangeability from mechanically similar parts that would require PCB changes, helping engineers compare alternatives without treating a same-family option as automatically safe to substitute.
PCA9516APW - 5-Channel 400kHz I2C Bus Hub | NXP
The NXP Semiconductors PCA9516APW is a 5-channel bidirectional I2C-bus and SMBus hub rated for operation up to 400 kHz, with open-drain input/outputs and individual active-HIGH repeater enables in a 16-pin TSSOP package. It extends an I2C bus by buffering both clock and data lines, allowing five downstream buses with up to 400 pF each. An I2C bus hub is an interface IC that regenerates and buffers SDA and SCL signals between a controller and multiple bus segments. In the product hierarchy, a bus hub is a type of I2C interface controller, interface IC, and semiconductor. This buffering approach reduces the loading presented to the upstream controller, separates downstream capacitive loads, and permits cable or board-distance extension where the original I2C bus would otherwise exceed its capacitance limit. Key features include five bidirectional repeater channels, active-HIGH individual repeater enable inputs, lock-up-free operation, support for arbitration and clock stretching across the repeater, and powered-off high-impedance I2C pins. The device accommodates Standard-mode and Fast-mode I2C devices and multiple controllers. Its operating supply range is identified by NXP as beginning at 2.3 V, while the available search results specifically describe 2.5 V and 3.3 V support. Each downstream segment can accommodate up to 400 pF. This is important because I2C uses open-drain signaling, and capacitance on SDA and SCL raises rise time and can cause timing failures. The PCA9516A architecture isolates each buffered bus segment, allowing unused channels to be disabled independently. Its powered-off high-impedance behavior helps avoid unwanted bus contention during shutdown or partial power-down conditions. Typical uses include extending sensor and EEPROM networks, isolating industrial control modules, supporting SMBus systems, and distributing clock and data to separate I2C branches. The hub is especially useful when multiple relatively slow devices create substantial bus capacitance or when a PCB layout requires electrical separation between controller and peripheral buses. Designers should connect pull-up resistors to each bus segment and place them in accordance with the bus voltage, capacitance, and rise-time requirements. Trace lengths, connector capacitance, and leakage current must be included in the worst-case electrical assessment. Disabled channels should not be assumed to provide isolation unless the enable state and powered-off pin behavior are verified for the operating condition. This page combines verified manufacturer and distributor information with practical bus-extension guidance, pricing context, package details, and replacement analysis. It is intended to help engineers determine whether a five-channel buffered hub is appropriate before committing a board design to the TSSOP-16 footprint.
PCA9517D - 2-Channel 400kHz I2C Level Translator | Texas Instruments
The Texas Instruments PCA9517D is a two-channel bidirectional I2C and SMBus buffer/repeater operating up to 400kHz, with a supply voltage range of 2.7V to 5.5V and an 8-pin SOIC package. It provides voltage-level translation between low-voltage and higher-voltage bus domains and includes independent enable control for each side. What is a level-translating I2C buffer/repeater? It is an interface IC that connects two bidirectional serial buses operating at different voltage levels. The PCA9517D belongs to the I2C repeater and voltage-level-translator hierarchy, within interface ICs and semiconductors. Its two channels isolate bus voltage domains while preserving bidirectional data transfer, helping systems separate voltage levels without redesigning the upstream and downstream devices. Key verified features include two bidirectional channels, 400kHz operation, and compatibility with I2C and SMBus applications. The device can translate signals between low-voltage domains, including voltages down to 0.9V in the NXP-described PCA9517 function, and higher-voltage domains from 2.7V to 5.5V. The 8-SOIC package supports conventional surface-mount assembly and is identified by Texas Instruments as a two-channel signal buffer/repeater. The PCA9517D is useful when two I2C domains require different voltage ranges or when a bus segment needs buffering. Its two independent enables allow unused channels to be disabled, while the bidirectional architecture supports data flow in either direction. The verified distributor listing specifies 400kHz operation and an 8-SOIC package; detailed electrical limits should be confirmed against the manufacturer datasheet before production release. Typical applications include voltage-level translation between low-voltage sensors and higher-voltage controllers, SMBus isolation between subsystems, interface conditioning between PCB domains, and embedded systems where I2C devices use different supply rails. Because it is a repeater rather than a regulator, system designers must verify pull-up voltage, bus capacitance, propagation delay, and enable sequencing on each side. A key design consideration is that both sides of each channel must be properly referenced and pulled up for the voltage domains being supported. Do not assume that level translation removes the need for correct pull-up placement or timing review. Confirm the exact pinout, enable polarity, maximum loading, and operating limits from the official Texas Instruments documentation. This page combines verified distributor information, manufacturer product identity, interface-function context, package information, and practical selection guidance to support engineers searching for a PCA9517D replacement, equivalent, pinout, price, or I2C level-translation solution.
PCA9517DR - 2-Channel 400kHz I2C Level Translator | Texas Instruments (Tape & Reel)
The Texas Instruments PCA9517DR is a two-channel bidirectional I2C and SMBus buffer/repeater operating up to 400kHz, with a supply voltage range of 2.7V to 5.5V and an 8-pin SOIC package. It provides voltage-level translation between low-voltage and higher-voltage bus domains and includes independent enable control for each side. What is a level-translating I2C buffer/repeater? It is an interface IC that connects two bidirectional serial buses operating at different voltage levels. The PCA9517DR belongs to the I2C repeater and voltage-level-translator hierarchy, within interface ICs and semiconductors. Its two channels isolate bus voltage domains while preserving bidirectional data transfer, helping systems separate voltage levels without redesigning the upstream and downstream devices. Key verified features include two bidirectional channels, 400kHz operation, and compatibility with I2C and SMBus applications. The device can translate signals between low-voltage domains, including voltages down to 0.9V in the NXP-described PCA9517 function, and higher-voltage domains from 2.7V to 5.5V. The 8-SOIC package supports conventional surface-mount assembly and is identified by Texas Instruments as a two-channel signal buffer/repeater. The PCA9517DR is useful when two I2C domains require different voltage ranges or when a bus segment needs buffering. Its two independent enables allow unused channels to be disabled, while the bidirectional architecture supports data flow in either direction. The verified distributor listing specifies 400kHz operation and an 8-SOIC package; detailed electrical limits should be confirmed against the manufacturer datasheet before production release. Typical applications include voltage-level translation between low-voltage sensors and higher-voltage controllers, SMBus isolation between subsystems, interface conditioning between PCB domains, and embedded systems where I2C devices use different supply rails. Because it is a repeater rather than a regulator, system designers must verify pull-up voltage, bus capacitance, propagation delay, and enable sequencing on each side. A key design consideration is that both sides of each channel must be properly referenced and pulled up for the voltage domains being supported. Do not assume that level translation removes the need for correct pull-up placement or timing review. Confirm the exact pinout, enable polarity, maximum loading, and operating limits from the official Texas Instruments documentation. This page combines verified distributor information, manufacturer product identity, interface-function context, package information, and practical selection guidance to support engineers searching for a PCA9517DR replacement, equivalent, pinout, price, or I2C level-translation solution.
PCA9518DW - 5-Channel 400kHz I2C Hub | Texas Instruments
The Texas Instruments PCA9518DW is an expandable five-channel bidirectional I2C and SMBus buffer hub operating from a 3 V to 3.6 V supply at up to 400 kHz. It is packaged in a 20-pin SOIC and separates buffered SDA and SCL paths into groups that can each support up to 400 pF of bus capacitance. An I2C hub is a specialized interface IC that buffers and divides one upstream I2C or SMBus segment into multiple downstream segments. The I2C protocol limits the total capacitance supported by a conventional bus to 400 pF, where the limit is determined by connected devices and cable length. The PCA9518 expands that usable bus by placing isolated buffer groups between the upstream pins and downstream channel pins, allowing additional devices to be connected without redesigning the upstream bus. Key characteristics include five bidirectional downstream channels, operation across a 3 V to 3.6 V supply range, 400-kHz bus operation, and an expandable topology supported by the TI product family. Each downstream group buffers both clock and data in the forward direction while providing the return path required by the I2C protocol. The buffered arrangement also helps isolate capacitance between downstream segments rather than presenting every device directly to the upstream bus. The PCA9518 is useful in systems where a host controller must reach multiple embedded subsystems, sensor boards, EEPROMs, power monitors, or other low-speed peripherals beyond the practical capacitance of one unbuffered bus segment. Because the device is a bidirectional buffer hub rather than a general-purpose GPIO expander, it does not add individual digital input or output ports. It preserves the two-wire serial protocol while changing the electrical segmentation of the network. Typical uses include multi-board test equipment, industrial controllers, programmable instrumentation, server management boards, and modular sensor systems. The 20-pin SOIC package also supports conventional surface-mount assembly, although a footprint confirmation against the specific manufacturer ordering information is recommended before layout release because the verified data does not provide a complete pin table. When laying out a design, treat every upstream and downstream SCL and SDA connection as a separate routed segment and place the hub close to the point where the bus must be divided. Keep stub lengths short on high-capacitance branches and follow the manufacturer layout guidance for pull-up placement. Because the verified sources describe the function, package, voltage range, frequency, and bus-capacitance segmentation but do not publish detailed pin assignments or timing tables, those specific values should be confirmed against the official PCA9518 datasheet before release.
PCA9518PW - Expandable 5-Channel I2C Hub | NXP
The NXP PCA9518PW is a BiCMOS integrated circuit designed as an expandable five-channel I2C-bus hub for I2C and SMBus systems. According to the NXP product information, the device operates from a wider 2.3 V to 3.6 V supply range and improves partial power-down performance by keeping the I2C-bus I/O pins in a high-impedance state when VDD is below 2.0 V. The component is supplied in a 20-pin TSSOP package, making it suitable for compact embedded systems that require bus expansion or buffering between a host controller and multiple peripheral devices. The PCA9518 is a type of I2C bus buffer, a specialized interface IC within the broader I2C interface and semiconductor hierarchy. Its primary function is to extend or segment an I2C bus by providing five buffered downstream channels and a separate upstream channel. This allows a controller to communicate with more peripherals than the electrical limitations of a direct bus connection would permit, while helping isolate capacitive loading and improve signal integrity in multi-device systems. The expandable architecture supports systems where additional downstream buses can be added as peripheral count and board complexity increase. Key electrical characteristics include a 2.3 V to 3.6 V operating-supply range, partial power-down support, and operation in systems using either I2C or SMBus signaling. The high-impedance bus-pin behavior below 2.0 V is especially useful when a system must prevent unintended bus activity during shutdown, reset, or partial power sequencing. The 20-pin TSSOP package provides a surface-mount form factor suitable for industrial control, embedded instrumentation, communications equipment, and consumer-accessory designs. The device is used as a bus hub rather than as a power regulator or level translator. A typical implementation places the PCA9518PW between the host I2C controller and a group of downstream peripherals. Each downstream channel can serve a separate device group, helping distribute bus capacitance and provide a controlled interface boundary. Designers must still verify pull-up resistor placement, voltage compatibility, channel-loading conditions, and the power-state behavior of every connected device. For applications requiring more than five downstream channels, multiple PCA9518 hubs can be arranged in an expandable topology. This makes the part useful in modular industrial and test systems where a controller must support multiple removable or distributed peripheral groups. The 2.3 V to 3.6 V supply range also aligns it with common low-voltage digital systems, although every connected I2C device must support the same signaling voltage and compatible electrical limits. A key design consideration is preserving the high-impedance behavior during partial power-down. The bus pins should not be externally forced when VDD falls below 2.0 V, because doing so can compromise the intended isolation behavior. PCB layout should keep the hub close to the controller or branch point, follow the datasheet’s recommended decoupling and pull-up arrangements, and avoid long unprotected branches that increase capacitance and reduce rise-time margin. Engineers should confirm the final bus timing and voltage levels with the complete peripheral population. This product page combines verified manufacturer information, distributor identification, package data, and engineering-oriented selection guidance. It also distinguishes the confirmed PCA9518PW attributes from alternatives that require independent pinout and parameter verification rather than presenting them as automatic replacements.
PCA9527DP - 3-Ch HDMI DDC/CEC I2C Bus Buffer | NXP
The NXP Semiconductors PCA9527DP is a 3-channel bidirectional open-drain bus buffer for HDMI Display Data Control (DDC) clock, data and Consumer Electronic Control (CEC), operating at up to 400 kHz from a 2.7 V to 5.5 V supply in a 10-pin TFSOP (10-TSSOP) package. A bus buffer (also called a bus extender or repeater) is a signal-conditioning device inserted between a master and a slave on a two-wire serial bus such as I2C-bus, SMBus or HDMI DDC. It belongs to the broader family of interface ICs and signal buffers, repeaters and splitters. Its role is to isolate bus capacitance on either side, so each segment sees only its own load, allowing longer cables and more devices than the raw bus standard permits. Key features of the PCA9527 include three independent bidirectional channels for SDA, SCL and CEC, support for the full 400 kHz Fast-mode I2C-bus operating range, and overvoltage-tolerant SDAx and SCLx pins. Propagation delay is a low 115 ns and input capacitance is only 8 pF, preserving setup and hold margins on long HDMI DDC cables. Architecturally, the PCA9527 uses open-drain bidirectional buffer stages with rise-time acceleration (buffer accelerator) circuitry. This rising-edge accelerator drives the bus high actively, compensating RC charging losses across long DDC lines while retaining all operating modes of the I2C-bus system during level shifting. According to the NXP datasheet, using the PCA9527 enables the system designer to isolate bus capacitance to meet the HDMI DDC version 1.3 distance specification. Typical applications include HDMI source and sink equipment (set-top boxes, TVs, monitors, AV receivers) where DDC/CEC lines must traverse cables or backplanes, notebook docking stations, and any system that extends I2C-bus or SMBus segments beyond the standard capacitance limit. The dedicated third channel carries CEC without consuming I2C channels. Design consideration: keep pull-up resistor values on both bus segments sized per segment capacitance; the accelerator helps but very heavy loads on the downstream side still degrade rise times, so verify rise-time compliance at the far end of the HDMI cable. This page adds value beyond the manufacturer datasheet by synthesizing distributor availability data, drop-in replacement guidance for this EOL part, practical design notes, and a comparison table in one place. Note: the PCA9527DP is listed by NXP as End of Life; pricing shown is indicative and all designs should plan a replacement strategy (as of 2026-10-20).
PCA9527DP,118 - 3-Ch I2C/HDMI DDC CEC Bus Buffer | NXP
The NXP PCA9527DP,118 is a 3-channel bidirectional open-drain bus buffer that supports up to 400 kHz I2C-bus operation, operates from a 2.7 V to 5.5 V supply, and provides a typical 115 ns propagation delay, housed in a 10-pin TSSOP (10-TFSOP, 0.118 inch width) package with the ,118 suffix denoting a Tape & Reel, RoHS-compliant shipping option. A bus buffer (also called a bus extender or repeater) is an interface IC inserted in series with a two-wire serial bus such as I2C (Inter-Integrated Circuit) or SMBus (System Management Bus). Within the broader hierarchy of interface semiconductors, bus buffers sit alongside level translators and line drivers, and their role is to segment bus capacitance, regenerate signal edges, and isolate parasitic loading so the bus can be longer or drive more devices than the raw open-drain bus standard would otherwise permit. Key features of the PCA9527 include three independent bidirectional channels dedicated to the HDMI Display Data Channel (DDC) clock and data lines plus the Consumer Electronics Control (CEC) line, support for Fast-mode 400 kHz I2C and SMBus signaling, an active-HIGH EN enable pin with an internal pull-up of approximately 100 kOhm to VCC(B) that places the device in a low-power down state when disabled, and two separate power supply pins that allow voltage level shifting between the two sides of the bus. Technically, the device uses rise-time accelerators on each open-drain channel to actively speed up rising edges that would otherwise be limited by pull-up resistors and bus capacitance. Input capacitance is 8 pF per pin, minimizing loading on the source side, and supply current is specified up to 100 mA. Because the channels are bidirectional and open-drain, no direction-control signal is required, which is essential for the acknowledge-clock-stretching behavior of I2C and DDC. Typical applications are HDMI source, sink, repeater, and switch designs where DDC and CEC lines must be buffered between the HDMI connector and an HDMI processor, EDID EEPROM access circuits, set-top boxes, TVs, AV receivers, and projectors. The buffered DDC prevents a hot-plugged HDMI cable's cable capacitance from corrupting EDID reads, while CEC buffering preserves the single-wire control channel integrity. A key design consideration: connect the EN pin to VCC(B) if the buffer should be always active, and remember that re-enabling introduces a recovery delay, so power sequencing of the two supply pins matters in hot-plug HDMI systems. This page synthesizes distributor pricing tiers, drop-in alternative options, and practical HDMI DDC design notes that are not consolidated in the manufacturer datasheet.
PCA9534DBR - 8-Bit I2C GPIO Expander | Texas Instruments
Texas Instruments PCA9534DBR is an 8-bit I2C/SMBus general-purpose I/O expander with a 2.3 V to 5.5 V operating supply range, 400 kHz bus support, and a 16-pin SSOP package. It adds eight configurable digital input or output ports to a host processor while retaining control through the two-wire serial bus. The device also includes an interrupt output, configuration registers, and three hardware address pins that allow as many as eight devices to share one bus. An I/O expander is a low-power interface IC used to extend the number of general-purpose input/output lines available to an embedded system. Its hierarchy is GPIO expander, I/O expander, interface IC, and semiconductor. Instead of dedicating eight host-controller pins to each group of inputs and outputs, a system can place the PCA9534DBR on an I2C or SMBus and read or write its ports through register addresses. This is especially useful in compact industrial, consumer, communications, and embedded-control equipment where connector count and PCB area constrain the host MCU. Key features include eight general-purpose I/O ports, programmable addressing through A0, A1, and A2, and an open-drain interrupt output. The official Texas Instruments product information identifies a 2.3 V to 5.5 V VCC range and a 400 kHz I2C bus rate. Independent source information identifies the device as a CMOS 16-pin component and gives an operating temperature range of -40 °C to 85 °C. The SSOP package also makes the part suitable for surface-mount production and PCB footprint reuse where the package is verified against the alternate device. The PCA9534 architecture separates port data from configuration and addressing functions. A0, A1, and A2 hardware pins program the device address, while the serial interface provides access to the input, output, polarity, and configuration registers. The interrupt output allows the host to react when a selected input changes rather than continuously polling every port. Unlike devices with continuously enabled internal input pull-ups, the PCA9534 is noted by NXP as having no internal I/O pull-up resistor, reducing power consumption when outputs are held low; external pull-ups may therefore be required according to the application circuit. Typical uses include remote push-button inputs, LED and relay-control outputs, sensor and switch interfaces, backlight control, and expansion of a host processor's limited GPIO. The 400 kHz bus rate supports routine control traffic rather than high-bandwidth data transfer. Firmware should address each expander through its hardware-configured base address and initialize the configuration and polarity registers before changing port directions. Designers should verify pull-up requirements, address uniqueness, bus capacitance, and interrupt polarity for every connected device. Pull-up resistors should be sized for the lowest operating voltage and the complete bus population. I2C trace length and routing also matter because this low-power expander commonly shares a bus with sensors, EEPROMs, and other peripherals. Software for PCF8574-based designs may require changes when migrating to PCA9534 because the enhanced register behavior is not identical despite hardware compatibility. This product record combines verified manufacturer and distributor information, same-footprint alternatives, application guidance, and design cautions. It also distinguishes genuine pin-compatible choices from devices that only have similar functions, helping engineers shorten replacement evaluation without overlooking firmware and electrical differences.
PCA9534DW - 8-Bit I2C GPIO Expander | Texas Instruments
The Texas Instruments PCA9534DW is an 8-bit I2C/SMBus low-power I/O expander with an interrupt output and configuration registers, operating from 2.3 V to 5.5 V in a 16-SOIC package. It provides eight general-purpose input/output ports, 400 kHz bus operation, power-on reset, and programmable input, output, and high-impedance modes according to the manufacturer product page and PCA9534 datasheet. An I2C I/O expander is a peripheral that adds digital input and output pins to a host controller through a two-wire serial interface. The PCA9534 belongs to the GPIO expander and port-extension hierarchy, where a microcontroller or processor uses serial addressing to control external LEDs, relays, sensors, or digital status signals while reducing direct GPIO requirements. Key features include eight configurable GPIO lines, a 2.3 V to 5.5 V VCC range, 400 kHz I2C/SMBus operation, push-pull outputs, an interrupt output, and configuration registers. The device is identified in distributor data as a 16-SOIC I/O expander. Its low-power design is useful for embedded systems that need additional control or monitoring lines without dedicating eight host-controller pins to every function. The PCA9534 uses configuration registers to determine whether each port pin operates as input, output, or high impedance. The interrupt output provides a hardware indication of input or register conditions, while the I2C interface allows the host to read and update port state. The 400 kHz bus rate supports relatively compact embedded control systems, although actual system throughput depends on bus capacitance, pull-up implementation, and host timing. Typical applications include low-power sensor nodes, industrial control boards, LED or indicator expansion, relay-control interfaces, and general embedded GPIO expansion. In designs using the PCA9534DW, the host processor must provide valid I2C pull-ups, respect the 2.3 V to 5.5 V supply range, and account for the interrupt pin when configuring input-change detection. The 16-SOIC package also requires a PCB footprint matching the SOIC-16 layout. For sourcing, distributor listings provide current market, price, and inventory information, while the manufacturer datasheet remains the controlling reference for pinout, register behavior, electrical limits, and application use. Product availability should be checked directly with an authorized distributor because inventory and pricing change over time.
PCA9534PW - 8-Bit I2C I/O Expander | NXP Semiconductors
The NXP Semiconductors PCA9534PW is an 8-bit CMOS I2C-bus and SMBus low-power I/O port expander with interrupt output, operating from 2.3 V to 5.5 V at up to 400 kHz and housed in a 16-pin TSSOP package. It adds eight configurable GPIO lines while sharing its serial bus with other peripherals. An I/O expander is an interface IC that extends a host microcontroller or processor through a serial bus instead of consuming eight parallel pins. The PCA9534 belongs to the I/O expander hierarchy, expands GPIO resources, and connects through the I2C interface to embedded control systems. Its low-power design is useful when the additional lines must remain available without continuously increasing the power budget. The PCA9534 provides eight general-purpose parallel input or output ports, an interrupt output, and configuration registers. Three hardware address pins, A0, A1, and A2, program the device address and permit multiple expanders on one I2C bus. Its 400 kHz bus capability and 2.3 V to 5.5 V operating range make it suitable for common embedded 3.3 V and 5 V systems. The device is compatible with I2C and SMBus-oriented system architectures and is designed to simplify firmware-controlled expansion of external controls and sensed signals. Inputs and outputs can be configured according to system requirements, while the interrupt output allows a controller to respond when an enabled input changes. The verified product information specifically describes PCA9534PW as the low-power TSSOP16 version of the PCA9554 family, with internal I/O pull-up resistors removed. Typical applications include industrial control boards, sensor interfaces, LED and relay-control boards, compact embedded modules, and small controller platforms that need extra parallel lines without redesigning the host package. The TSSOP-16 package also supports standard surface-mount assembly, although the exact pin names and dimensions must be confirmed in the manufacturer datasheet before layout. Designers should verify address selection, pull-up requirements, voltage compatibility, and interrupt polarity on the assembled PCB. Because the verified material identifies pin and I2C compatibility with PCF8574 while also requiring software changes, firmware should be reviewed when migrating between those devices. This page combines verified NXP, TI, and distributor information with application guidance and sourcing notes.
PCA9534PWR - 8-Bit I2C I/O Expander | NXP Semiconductors (Tape & Reel)
The NXP Semiconductors PCA9534PWR is an 8-bit CMOS I2C-bus and SMBus low-power I/O port expander with interrupt output, operating from 2.3 V to 5.5 V at up to 400 kHz and housed in a 16-pin TSSOP package. It adds eight configurable GPIO lines while sharing its serial bus with other peripherals. An I/O expander is an interface IC that extends a host microcontroller or processor through a serial bus instead of consuming eight parallel pins. The PCA9534 belongs to the I/O expander hierarchy, expands GPIO resources, and connects through the I2C interface to embedded control systems. Its low-power design is useful when the additional lines must remain available without continuously increasing the power budget. The PCA9534 provides eight general-purpose parallel input or output ports, an interrupt output, and configuration registers. Three hardware address pins, A0, A1, and A2, program the device address and permit multiple expanders on one I2C bus. Its 400 kHz bus capability and 2.3 V to 5.5 V operating range make it suitable for common embedded 3.3 V and 5 V systems. The device is compatible with I2C and SMBus-oriented system architectures and is designed to simplify firmware-controlled expansion of external controls and sensed signals. Inputs and outputs can be configured according to system requirements, while the interrupt output allows a controller to respond when an enabled input changes. The verified product information specifically describes PCA9534PWR as the low-power TSSOP16 version of the PCA9554 family, with internal I/O pull-up resistors removed. Typical applications include industrial control boards, sensor interfaces, LED and relay-control boards, compact embedded modules, and small controller platforms that need extra parallel lines without redesigning the host package. The TSSOP-16 package also supports standard surface-mount assembly, although the exact pin names and dimensions must be confirmed in the manufacturer datasheet before layout. Designers should verify address selection, pull-up requirements, voltage compatibility, and interrupt polarity on the assembled PCB. Because the verified material identifies pin and I2C compatibility with PCF8574 while also requiring software changes, firmware should be reviewed when migrating between those devices. This page combines verified NXP, TI, and distributor information with application guidance and sourcing notes.