PCA9500PW - 8-Bit I/O Expander with 2-kbit EEPROM | NXP
N.º de pieza: PCA9500PW ✓ ActivoPCA9500PW Descripción general
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.
Alternativas directas para PCA9500PW — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con PCA9500PW (mismo factor de forma y huella) — difiere en Package, Interface, Interrupt Output, Product Type, Supply Voltage Range.
PCA9534PW
✅ Sustitución directaConsulte el precio
Ver hoja de datos →PCA9518PW
✅ Sustitución directaConsulte el precio
Ver hoja de datos →PCF8574PW
✅ Sustitución directaConsulte el precio
Ver hoja de datos →PCA9500PW Especificaciones
| Product Type | 8-bit I2C-bus and SMBus I/O port expander with EEPROM |
| Number of I/O Pins | 8 pins |
| I/O Direction Control | Independent input or output configuration per pin |
| I/O Port Type | Quasi-bidirectional |
| Integrated EEPROM Capacity | 2 kbit |
| Bus Interface | I2C-bus and SMBus |
| Maximum Bus Frequency | 400 kHz |
| Supply Voltage Range | 2.5 V to 3.6 V |
| Rango de temperatura de funcionamiento | -40 °C to +85 °C |
| Hardware Address Inputs | 3 address pins |
| Maximum Devices on One Bus | 8 devices |
| Encapsulado | 16-pin TSSOP |
| Tipo de montaje | Surface mount |
| GPIO and EEPROM Addressing | Two separate devices visible to the bus master |
| Reference Interface | PCF8574-compatible configuration method |
Guía de configuración de pines de PCA9500PW 16-pin tssop
Configuración de pines para PCA9500PW (encapsulado 16-pin tssop). La numeración de pines, las funciones y los diagramas de conexión se definen en la hoja de datos del fabricante. Consúltela para conocer el footprint exacto y las directrices de soldadura.
No hay datos detallados de patillaje disponibles para PCA9500PW.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
PCA9500PW es adecuado para 6 aplicacións: LED Status and Indicator Control, Switch and Interlock Monitoring, Microcontroller Pin-Count Reduction, Nonvolatile Configuration Storage, Industrial Control and Sensor Interface Boards, Programmable Control and Test Panels.
LED Status and Indicator Control
The PCA9500PW fits LED indicator boards because its eight quasi-bidirectional data pins can be independently assigned as outputs and drive board-level status lamps. The host controller writes configuration and output data through the familiar I2C/SMBus interface at up to 400 kHz, reducing the number of direct host GPIO connections. NXP specifically identifies LED activation as an intended use. The principal design check is electrical drive capability: because the verified excerpts do not provide complete output-current curves, engineers should confirm that the selected LED, resistor, and pull-up arrangement remains within the device's detailed datasheet limits before release to production.
Recomendado
Switch and Interlock Monitoring
The PCA9500PW is useful for reading banks of switches, interlocks, and discrete board-level status signals while conserving host-controller pins. Each of its eight quasi-bidirectional ports can be assigned independently as an input, and the integrated 2.5 V to 3.6 V supply operation fits conventional embedded logic systems. The device communicates through I2C or SMBus at up to 400 kHz, allowing status polling alongside other bus peripherals. Designers should verify input thresholds, pull-up behavior, and the complete timing characteristics from the NXP datasheet because those detailed electrical values are not present in the supplied source excerpts.
Recomendado
Microcontroller Pin-Count Reduction
The PCA9500PW addresses the common constraint of having too few direct GPIO pins on a microcontroller, host processor, or compact embedded controller. It adds eight configurable quasi-bidirectional I/O lines over a shared two-wire bus while operating from 2.5 V to 3.6 V. Three hardware address pins permit up to eight PCA9500 devices on one system, and the bus master accesses the GPIO and EEPROM as separate devices. This makes the part useful for systems that need modest expansion rather than dozens of high-speed GPIOs. Firmware should calculate both device addresses and account for bus pull-ups and capacitance during PCB implementation.
Recomendado
Nonvolatile Configuration Storage
The PCA9500PW is appropriate when a control board needs a small amount of nonvolatile data in addition to digital I/O. Its integrated 2-kbit EEPROM can store configuration values, board identification, calibration offsets, or operating flags, while the eight GPIO pins remain available for live control functions. NXP states that the bus master sees the GPIO controller and EEPROM as two separate devices, allowing software to address each function independently. Capacity planning should account for the small 2-kbit storage size, and production programming, write endurance, and retention values must be taken from the complete manufacturer datasheet because they are not included in the verified excerpts.
Recomendado
Industrial Control and Sensor Interface Boards
The PCA9500PW can serve as a compact interface between a low-voltage control processor and discrete industrial signals such as relay-control outputs, sensor-enable lines, or equipment-status inputs. Its 8-bit quasi-bidirectional port provides flexible mixed input/output operation, while the 2.5 V to 3.6 V supply range supports conventional embedded control logic. The 400 kHz bus rate is appropriate for slow supervisory updates rather than high-bandwidth data acquisition. Engineers must isolate or level-shift any external signal that exceeds the verified supply range and must confirm the actual output current, input thresholds, and timing limits before connecting field wiring.
Recomendado
Programmable Control and Test Panels
The PCA9500PW is well suited to compact programmable control panels that combine pushbuttons, status indicators, and stored setup data. A host can configure individual pins as inputs or outputs through the I2C/SMBus interface and use the 2-kbit EEPROM to retain panel configuration between power cycles. Up to eight address-selectable devices can expand a larger multi-panel system without consuming separate address pins from the controller. During hardware design, verify the package land pattern and pin numbering against the official NXP datasheet, provide suitable bus pull-ups, and ensure the quasi-bidirectional outputs have enough pull-up strength for the connected loads.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para PCA9500PW — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | PCA9534PW | PCA9518PW | PCF8574PW |
|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 16-pin TSSOP | 16-pin TSSOP | 16-pin TSSOP | 16-pin TSSOP |
| Product Function | 8-bit I2C/SMBus I/O expander | I/O expander | I/O port | 8-bit I2C I/O expander |
Diferenciadores clave
- Integrated nonvolatile storage alongside GPIO expansion (frente a PCF8574PW)
- Manufacturer-supported PCF8574-compatible replacement (frente a PCF8574PW)
- Addressable bus scalability (frente a PCA9518PW)
Notas de diseño
The PCA9500PW operates from 2.5 V to 3.6 V, so the host supply must remain inside that verified range. Place the device's supply decoupling capacitor close to the power pin and follow the NXP datasheet's recommended capacitance and layout. Do not infer operating behavior outside the range, and ensure the selected pull-up voltage does not exceed the permitted I/O voltage. Detailed absolute maximum ratings were not present in the supplied excerpts and must be checked in the manufacturer datasheet before applying external signals.
Use the official PCA9500PW 16-pin TSSOP land pattern and verify pin numbering against the NXP package drawing before releasing PCB artwork. Keep the I2C/SMBus traces short, route them away from noisy switching nodes, and provide pull-up resistors at the physical bus location rather than at an inconvenient remote point. The three address pins must be fixed to valid logic levels before the bus master begins scanning; floating address inputs could create an unintended device address.
Do not treat the eight quasi-bidirectional ports as unrestricted push-pull outputs. Their pull-up behavior affects both output drive and input sensing, so external loads, pull-up resistance, and attached logic levels must be checked against the complete NXP electrical characteristics. Also remember that the integrated EEPROM and GPIO controller are seen as separate devices by the bus master; changing one address mapping without updating firmware can leave the application addressing the wrong function.
Información de cumplimiento
The verified comparison references mention RoHS and REACH fields, but the supplied excerpts do not state their values. Compliance therefore remains unknown rather than being inferred from the manufacturer name or product family.