TCA9554DWT - 8-Bit I/O Expander, 400 kHz | Texas Instruments
MPN: TCA9554DWT ✓ פעילTCA9554DWT סקירה
An I/O expander is an interface IC that increases the number of digital lines available to a host processor. It sits between a microcontroller and external peripherals, translating bus commands into parallel input or output operations. This hierarchy connects I/O expander to interface IC, then to semiconductor and embedded control systems, reducing the number of pins required on a microcontroller when several switches, sensors, indicators, or control signals must be connected.
The TCA9554DWT provides separate configuration registers for input, output, and polarity inversion. Its interrupt output allows the host to detect a change on an input port without continuously polling the device. The weak pull-up capability can support open-drain-style bus arrangements and configurable input states, while the low-power design is suitable for embedded systems with limited energy budgets.
Communication uses the two-wire bidirectional I2C or SMBus interface. Three address pins allow multiple devices to coexist on the same bus, and the device operates across a broad 1.65 V to 5.5 V supply range. This voltage flexibility is useful in systems combining low-voltage digital logic with peripheral equipment operating from a 5 V rail.
Typical applications include industrial control panels, building automation, sensor and switch interfaces, LED and indicator control, appliance control boards, compact embedded systems, and low-power IoT equipment. The interrupt line is especially useful when several expander inputs must wake a host only after a meaningful state change.
Designers should review the manufacturer pin description table when assigning tracks and verify the address configuration, pull-up behavior, and power sequencing. Bus rise times depend on capacitance, pull-up resistance, voltage, and topology, so scope measurements should confirm valid timing at the slowest supported bus speed. Use the Request a Quote form on this page for current commercial availability, lead time, and lot-related sourcing.
חלופות תחליף ישיר עבור TCA9554DWT — אותו מארז, תואם פין-לפין. חלקים במארז שונה הדורשים עיבוד מחדש של ה-PCB אינם נכללים.
וריאנטים בסדרה זו
דגמים מאותה סדרה התואמים Drop-in עם TCA9554DWT (אותו גורם צורה וטביעת רגל) — שונים ב Configuration Registers, Interrupt Output.
אין חלופות תואמות Drop-in עבור מוצר זה.
בקשת חלופותTCA9554DWT מפרטים
| Device Type | 8-bit I2C/SMBus I/O expander |
| Number of I/O Lines | 8 lines |
| Operating Supply Voltage Range | 1.65 V to 5.5 V |
| ממשק | I2C/SMBus |
| Maximum I2C Clock Frequency | 400 kHz |
| Supported Standard-Mode Clock Frequency | 100 kHz |
| Supported Fast-Mode Clock Frequency | 400 kHz |
| מספר פינים | 16 pins |
| מארז | 16-pin SOIC |
| General-Purpose Input Ports | 8 configurable input lines |
| General-Purpose Output Ports | 8 configurable output lines |
| Interrupt Output | Yes |
| Address Configuration Inputs | 3 address pins |
| Internal Pull-Up Capability | Weak pull-ups |
| Configuration Registers | Input, output, and polarity-inversion configuration registers |
| סוג הרכבה | Surface mount |
תצורת פינים של TCA9554DWT
| פין 1 | A0 — Address-selection input |
| פין 2 | A1 — Address-selection input |
| פין 3 | A2 — Address-selection input |
| פין 4 | SCL — Serial clock input |
| פין 5 | SDA — Serial data input/output |
| פין 6 | GND — Ground |
| פין 7 | INT — Interrupt output |
| פין 8 | P0 — General-purpose I/O port 0 |
| פין 9 | P1 — General-purpose I/O port 1 |
| פין 10 | P2 — General-purpose I/O port 2 |
| פין 11 | P3 — General-purpose I/O port 3 |
| פין 12 | P4 — General-purpose I/O port 4 |
| פין 13 | P5 — General-purpose I/O port 5 |
| פין 14 | P6 — General-purpose I/O port 6 |
| פין 15 | P7 — General-purpose I/O port 7 |
| פין 16 | VCC — Power supply input |
יישומים טיפוסיים
TCA9554DWT מתאים עבור 6 יישוםs: Industrial Control Panels, Building Automation Interfaces, Sensor and Switch Aggregation, LED and Indicator Control, Appliance and Embedded Control, Low-Power IoT Equipment.
Industrial Control Panels
The TCA9554DWT is well suited to industrial control panels where limit switches, panel indicators, selectors, and relay-control signals would otherwise consume many microcontroller GPIO pins. Its eight configurable lines can be assigned as inputs or outputs, while the 1.65 V to 5.5 V operating range supports low-voltage control logic and 5 V peripherals. The interrupt output allows the controller to avoid continuous polling when a panel state changes. According to the Texas Instruments manufacturer datasheet, the device supports 400 kHz Fast-mode communication, reducing serial-update overhead when several panel events occur. Designers should still protect external lines from industrial transients and verify that all connected loads remain within the device's electrical limits.
מומלץ
Building Automation Interfaces
The TCA9554DWT can connect building-automation controllers to occupancy inputs, door contacts, status lamps, and actuator-enable signals through a compact serial interface. Its 8-bit parallel I/O structure reduces the number of host-controller pins required for auxiliary equipment, and the three address inputs permit several expanders on one I2C bus. The 400 kHz Fast-mode capability supports timely updates when multiple zones are active. The interrupt output is useful for waking the controller after an occupancy or contact change instead of maintaining constant polling cycles. For reliable operation, engineers should account for isolated transients, wiring length, common-mode conditions, pull-up resistance, and the electrical requirements of each connected field device.
מומלץ
Sensor and Switch Aggregation
The TCA9554DWT can aggregate digital thermistors with switch outputs, push buttons, door sensors, or discrete status flags into a compact bus-connected module. Each of its eight lines may be configured as an input or output, allowing a single device to handle both sensed events and control signals. The weak pull-up resources and configurable input registers help simplify open-drain-style sensing arrangements, while the dedicated interrupt output provides an event-driven path to the host processor. The Texas Instruments manufacturer datasheet confirms operation from 1.65 V to 5.5 V and support for 100 kHz and 400 kHz buses. Final design checks should include input thresholds, leakage current, debouncing strategy, bus pull-ups, and protection from connector-borne noise.
מומלץ
LED and Indicator Control
The TCA9554DWT provides eight output lines for status LEDs, segment indicators, and low-current display controls without requiring a dedicated GPIO pin on every indicator. Its configurable output and polarity-inversion registers simplify active-high versus active-low indicator wiring, and the serial interface makes it practical to update several indicators from a resource-constrained host. The broad 1.65 V to 5.5 V supply range can align with logic-level display drivers and embedded processors. For visible multiplexing or high-current illumination, add suitable transistor or driver stages instead of driving unsupported loads directly. Texas Instruments documents the device's low-power architecture and 400 kHz Fast-mode operation, which help reduce update time and energy use in compact control boards.
מומלץ
Appliance and Embedded Control
The TCA9554DWT is useful in appliance controllers and compact embedded systems that need keypad lines, mode indicators, door sensors, and auxiliary output controls. Its 16-pin SOIC package preserves PCB area, while the eight-line port allows one serial addressable device to replace several individual host GPIO connections. The interrupt output can notify the main controller when a user action or sensor event occurs, allowing the processor to remain in a lower-activity state between events. The Texas Instruments manufacturer datasheet identifies a low-power design, a 1.65 V to 5.5 V operating range, and Fast-mode capability up to 400 kHz. Validate startup states, address isolation, connector protection, and firmware handling of simultaneous input changes before production.
מומלץ
Low-Power IoT Equipment
The TCA9554DWT can extend a compact IoT controller with discrete status, wake, configuration, and actuator-control lines while retaining a low-power system architecture. Its interrupt output supports event-driven host behavior, which can reduce unnecessary serial polling between external state changes. The device operates across 1.65 V to 5.5 V and supports a 400 kHz bus, making it suitable for low-voltage embedded nodes as well as 5 V peripheral arrangements. The eight ports can be reconfigured through registers as system requirements change. According to the Texas Instruments manufacturer datasheet, the weak pull-ups and configuration registers support flexible input handling. Engineer the pull-up network and leakage budget carefully at the lowest system voltage to maintain valid bus rise times.
מומלץ
סיכום מוצרים מומלצים
נתוני עזר הנדסיים עבור TCA9554DWT — השוואה, הנחיות תכנון ומידע על תאימות.
מדריך בחירה
השוואה עם חלופות
| פרמטר | מוצר זה |
|---|---|
| Brand | Texas Instruments |
| Package | 16-pin SOIC |
| Number of I/O Lines | 8 |
| Operating Supply Voltage | 1.65 V to 5.5 V |
| Serial Interface | I2C/SMBus |
| Maximum Bus Clock Frequency | 400 kHz |
| Interrupt Output | Yes |
| Address Inputs | 3 |
| Pull-Up Capability | Weak pull-ups |
מבדילים עיקריים
- Eight individually configurable lines in a compact serial interface (לעומתPCA9554PWR)
- Event-driven host notification (לעומתPCF8574DWR)
- Broad low-voltage operating range (לעומתPCA9554PWR)
הערות תכנון
Route SCL and SDA as short, continuous traces away from switching nodes, high-current relay lines, and antenna structures. Place the associated pull-up resistors at the point that provides the weakest bus signal or the intended bus master, following the system-level I2C topology. Keep ground-return paths short and use a solid ground plane. With four address pins and an interrupt output, verify every footprint pad against the 16-pin SOIC pin-description table before fabrication.
Decouple the 1.65 V to 5.5 V supply close to the VCC pin and connect it to the ground reference with a low-impedance path. Select bypass capacitance and placement using the manufacturer datasheet recommendations and the switching characteristics of the surrounding board. If I2C pull-ups connect to a different supply voltage, verify that the SDA and SCL pins are never exposed to a voltage outside the device's permitted input range. A stable local supply reduces bus timing errors and prevents false interrupt events.
Do not treat every I2C I/O expander as a pin-compatible substitute. Confirm package dimensions, pin functions, address behavior, input thresholds, output-current limits, interrupt polarity, register layout, and firmware sequencing separately. For the TCA9554DWT, set the three address inputs to defined levels before communication starts, and ensure the host detects and clears interrupt conditions correctly. Also avoid floating unused inputs when their electrical state can influence system behavior.
Check I2C rise time at the worst-case combination of bus capacitance, pull-up resistance, supply voltage, and temperature. The 400 kHz operating limit does not guarantee 400 kHz operation on every wiring harness. Measure SCL and SDA at the electrically farthest device, and increase pull-up current or reduce bus capacitance if rise times are marginal. Keep the interrupt trace short and route it away from the serial bus when its timing margin is important.
מידע על תאימות
No explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statement appears in the product listings. Confirm current environmental and qualification documentation with the manufacturer before release.