TCA9554PWR - 8-Bit I2C I/O Expander | Texas Instruments
料号： TCA9554PWR ✓ 量产中TCA9554PWR 概述
An I/O expander is an interface IC used to extend the number of digital input and output lines available to a microcontroller or processor. The TCA9554 belongs to the I2C interface family within the broader interface-controller and power-management-system hierarchy. It is useful when a system needs additional control signals, status inputs, LEDs, relays, or switch sensing without allocating direct host-controller pins.
Key features include eight configurable I/O ports, an interrupt output for input-state changes, weak pull-up configuration registers, and a power-on reset that restores the default device state when the supply is cycled. The 1.65 V to 5.5 V operating range supports low-voltage embedded systems, while the 400 kHz bus capability allows relatively fast host-to-expander communication. The device also provides separate register-based control for input and output ports.
The TCA9554 uses the I2C or SMBus-compatible serial interface for register access and parallel port data transfer. Its address pins provide hardware configuration, reducing firmware complexity when several expanders share a bus. The interrupt output allows the host to remain in a low-power state until an input changes, rather than polling all eight inputs continuously. The interrupt behavior and configurable pull-up functions make the device useful for both active control and monitored input designs.
Typical applications include Arduino-compatible boards, ESP32 systems, industrial control panels, LED and relay interfaces, keypad or switch monitoring, home-automation controllers, and compact embedded instruments. In an ESP32 design, the expander can provide eight additional lines for sensors, indicators, or actuators while preserving the host processor resources for communication and control.
Designers should route I2C traces away from noisy switching nodes, confirm address assignments before software configuration, and account for open-drain bus pull-up requirements. The manufacturer datasheet is the authoritative reference for pin assignments, register behavior, electrical limits, and timing values. Use the device when a low-voltage, interrupt-capable, eight-line expansion function fits the system architecture.
This page consolidates the manufacturer product information, ordering details, technical comparisons, and practical implementation guidance for engineers evaluating TCA9554PWR in embedded and industrial designs.
直接替换替代料： TCA9554PWR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： TCA9554PWR （相同外形与封装尺寸） ——差异在于 Interface, Package, Interrupt Output, Product Type, Supply Voltage Range.
TCA9554APWR
✅ 直接替换📋 参考替代料（不在目录中）
TCA9534PWR
✅ 直接替换联系询价
查看数据手册 →PCA9534PWR
✅ 直接替换联系询价
查看数据手册 →PCA9554PWR
✅ 直接替换联系询价
查看数据手册 →PCA9557PWR
✅ 直接替换联系询价
查看数据手册 →PCF8574DWR
✅ 直接替换联系询价
查看数据手册 →TCA9554PWR 规格参数
| Device Type | 8-bit I/O expander |
| I/O Port Count | 8 ports |
| Supply Voltage Range | 1.65 V to 5.5 V |
| 接口 | I2C / SMBus |
| Maximum I2C Bus Frequency | 400 kHz |
| Interrupt Output | Yes |
| Configuration Registers | Yes |
| Weak Pull-Up Configuration | Yes |
| Address Inputs | A0, A1, A2 |
| Maximum Devices Per Bus | 8 devices |
| 封装 | 16-TSSOP |
| 引脚数量 | 16 pins |
| 安装类型 | Surface mount |
| Reset Behavior | Power-on reset to default state |
| Input Port Function | 8-bit general-purpose input |
| Output Port Function | 8-bit general-purpose output |
TCA9554PWR 16-tssop 引脚配置指南
TCA9554PWR（16-tssop 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： TCA9554PWR.
请参阅 数据手册 以查看完整引脚配置。
典型应用
TCA9554PWR 适用于 6 应用s: ESP32 Embedded Control, Arduino Sensor and Switch Interface, Industrial Control Panel, LED and Relay Control, Home Automation Controller, Test and Measurement Front Panel.
ESP32 Embedded Control
The TCA9554PWR fits ESP32 designs that need more digital lines than the host controller provides. Its eight configurable ports can operate as outputs for indicators or as inputs for switch and sensor status, while the I2C bus remains dedicated to host communication and register access. The device operates from 1.65 V to 5.5 V and supports 400 kHz bus operation, giving designers a practical way to add control capability without changing the main processor footprint. For a typical circuit, connect the TCA9554 to the ESP32 I2C pins and select the A0, A1, and A2 address lines for the intended bus map. The INT output can wake the host or trigger a service routine when an input changes state, reducing unnecessary polling. Check the ESP32 board voltage, pull-up arrangement, and host firmware register definitions before deployment.
推荐
Arduino Sensor and Switch Interface
The TCA9554PWR is useful on Arduino-compatible boards that must monitor several switches or read discrete sensor signals while retaining limited host pins. Its eight ports provide a common expansion point for button inputs, relay-control signals, and status LEDs, with each port configured through the device registers. The 1.65 V to 5.5 V operating range supports common low-voltage embedded systems, while the interrupt output allows software to respond to an input transition instead of continuously polling every port. Connect the expander through SDA and SCL, confirm the board's logic level, and provide suitable bus pull-ups for the operating voltage. The A0, A1, and A2 connections determine the device address and should be planned before multiple boards are assembled. Firmware must also account for the TCA9554 register map and the electrical behavior of the attached loads.
推荐
Industrial Control Panel
The TCA9554PWR provides a compact way to add panel I/O to an industrial controller. Eight configurable lines can monitor limit switches, panel indicators, or discrete sensor outputs, while the interrupt output lets the controller respond efficiently to changed inputs. Its 1.65 V to 5.5 V supply range fits low-voltage control rails, and the I2C/SMBus interface can operate at up to 400 kHz for routine register and port transfers. In a typical implementation, the expander sits near the panel connector so that short protected traces reach the field wiring, while the controller communicates over the board-level I2C bus. Address pins allow several panel sections or expander boards to coexist. Design for input protection, connector fault conditions, ground-bounce margin, and proper isolation between external wiring and sensitive controller circuitry.
推荐
LED and Relay Control
The TCA9554PWR can centralize digital control for LEDs, relay drivers, and other discrete loads when the host has insufficient output pins. The eight general-purpose output ports make the device suitable for grouped indicators or low-current control signals, while the interrupt input function can also be used on suitable mixed configurations. Because the device supports a 1.65 V to 5.5 V operating range and 400 kHz I2C communication, it fits many embedded power rails and control buses. Place the expander near the driven circuitry to minimize switching-node exposure, and use appropriate driver transistors or interface circuits for relays and inductive loads. Verify port current limits and voltage levels in the manufacturer datasheet before connecting a load. Firmware should establish the output configuration during startup to avoid unintended transient states.
推荐
Home Automation Controller
The TCA9554PWR is a practical expansion component for compact home-automation controllers that combine local switches, relays, and indicator LEDs. The controller can read eight local input conditions, operate additional output ports, and receive an interrupt when a monitored line changes. Its low 1.65 V to 5.5 V supply range supports common embedded logic levels, while the address pins make it possible to combine multiple expanders on one I2C bus. A typical design places the TCA9554 near the connector or relay-driver section, keeps I2C routing away from switching nodes, and uses firmware to map logical functions to ports. Ensure that inductive or high-energy loads use suitable protection and driver circuitry rather than driving them directly from the expander. Confirm the interrupt polarity and default port states in the datasheet before finalizing the application behavior.
推荐
Test and Measurement Front Panel
The TCA9554PWR can expand front-panel controls and status signals in compact test and measurement equipment. Eight ports can operate as inputs for function buttons, limit indicators, or remote command signals, and as outputs for control of panel lamps or external equipment. The 1.65 V to 5.5 V range allows integration with low-voltage control logic, while the interrupt output helps the instrument respond to user activity without frequent polling. The I2C bus can run at up to 400 kHz, making register access practical alongside routine measurement-control traffic. Place the device near the front-panel connector, keep the serial bus away from high-impedance analog paths, and use the address inputs to distinguish multiple expansion sections. Validate input thresholds, output drive limits, and power-up states against the specific panel circuitry and manufacturer datasheet.
推荐
推荐产品汇总
工程参考数据： TCA9554PWR ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | TCA9554APWR | TCA9534PWR | PCA9534PWR | PCA9554PWR | PCA9557PWR | PCF8574DWR |
|---|---|---|---|---|---|---|---|
| Package | 16-TSSOP | 16-TSSOP | 16-TSSOP | 16-TSSOP | 16-TSSOP | 16-TSSOP | 16-SOIC |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | Texas Instruments |
| I/O Port Count | 8 ports | 8 ports | 8 ports | 8 ports | 8 ports | 8 ports | 8 ports |
| Interface | I2C / SMBus | I2C / SMBus | I2C | I2C | I2C | I2C | I2C |
关键差异点
- Eight-port expansion with interrupt support （对比 TCA9534PWR)
- Low-voltage operating range （对比 PCA9534PWR)
- Multiple devices on one bus （对比 PCA9557PWR)
设计说明
Decouple the TCA9554PWR supply with local high-frequency and bulk capacitance placed close to the device. The exact capacitor values should follow the manufacturer datasheet and the host-board power strategy. Keep the 1.65 V to 5.5 V operating range in mind, and ensure that pull-up resistors on SDA and SCL do not exceed the selected I/O voltage.
Route SDA and SCL as short, continuous traces away from switching nodes, relay drivers, and high-current return paths. The interrupt line is sensitive to signal integrity, so avoid routing it parallel to noisy edges where possible. Confirm the A0, A1, and A2 address connections before routing dependent circuits, because changing these links changes the device address used by firmware.
Do not assume that a 16-pin TSSOP alternative has identical pin functions or software registers. Check address inputs, interrupt polarity, reset behavior, input thresholds, output drive limits, and default port states in each manufacturer datasheet. The TCA9554PWR has no general-purpose reset pin in the product description, so power-on reset is obtained by cycling the supply.
合规信息
The retrieved manufacturer and distributor listings do not provide explicit compliance declarations. Confirm RoHS, REACH, automotive qualification, lead-free, halogen-free, and conflict-minerals status against the current manufacturer product documentation before release.
