PCA9538PWR - 8-Bit I2C I/O Expander | NXP | TSSOP-16 (Tape & Reel)
料号： PCA9538PWR ✓ 量产中PCA9538PWR 概述
An I/O expander is an interface IC that extends a system’s digital input/output capability. The PCA9538 belongs to the hierarchy of GPIO expander, serial interface controller, and embedded peripheral. Its registers support configurable input, output, or high-impedance operation, while the interrupt output lets the host respond to selected port events without continuously polling all eight lines.
Key features include eight general-purpose I/O lines, 2.3 V to 5.5 V operation, 400 kHz I2C/SMBus support, and dedicated interrupt and reset functions. The low-power design is useful in embedded control, sensor-interface, and power-management systems where a compact serial interface can replace several parallel host-controller pins.
The device communicates through the two-line bidirectional bus using SCL and SDA. Its interrupt output provides event signaling, while reset provides a defined initialization path for the port and configuration state. These functions simplify firmware-driven GPIO expansion, particularly when the host must monitor external controls or remotely drive logic-level loads.
Typical applications include ACPI power-switch control, sensor and actuator interfacing, push-button and indicator handling, and general embedded GPIO expansion. Designers should account for the selected port direction, pull-up requirements on SDA and SCL, and the electrical characteristics of every signal driven through the expander.
For robust PCB implementation, place the serial-bus pull resistors close to the relevant bus nodes and keep the TSSOP routing short and clean. Review address configuration and firmware register access before operation, especially in systems with several I2C peripherals or multiple expanders on the same bus.
This page consolidates the verified manufacturer and distributor information, separates confirmed specifications from data gaps, and provides practical design guidance for engineers evaluating PCA9538PWR. It also records sourced drop-in alternatives where the available evidence supports pin and package compatibility.
直接替换替代料： PCA9538PWR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
该产品暂无直接替换替代料。
请求替代料PCA9538PWR 规格参数
| Product Type | 8-bit I2C-bus/SMBus I/O expander |
| Number of I/O Ports | 8 |
| Supply Voltage Range | 2.3 V to 5.5 V |
| 接口 | I2C-bus and SMBus |
| Bus Frequency | 400 kHz |
| Interrupt | Yes |
| Reset | Yes |
| Configuration Registers | Yes |
| Device Pin Count | 16 pins |
| 封装 | TSSOP-16 |
| 工作温度范围 | -40 C to +85 C |
| 安装类型 | Surface mount |
| Interface Signals | SCL and SDA |
| Port Modes | Input, output, and high-impedance operation |
| Manufacturer | NXP Semiconductors |
PCA9538PWR tssop-16 引脚配置指南
PCA9538PWR（tssop-16 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： PCA9538PWR.
请参阅 数据手册 以查看完整引脚配置。
典型应用
PCA9538PWR 适用于 6 应用s: ACPI Power-Switch Control, Embedded Sensor Interfacing, Push-Button and Indicator Handling, Industrial Control Module, Communication and Network Equipment, Power-Sequencing Support.
ACPI Power-Switch Control
The PCA9538PWR fits ACPI power-switch and system-control designs because it adds eight serial-controlled GPIO lines while operating from 2.3 V to 5.5 V. A host processor can use SCL and SDA to update output states while the interrupt output can signal selected input events. This reduces parallel GPIO demand on the host and keeps control wiring organized. Verify each switched load’s voltage, current, polarity, and off-state requirements against the device electrical limits.
推荐
Embedded Sensor Interfacing
The PCA9538PWR is useful for digital sensor and actuator nodes that need more control or status lines than the host microcontroller can expose directly. Its eight general-purpose ports can represent sensor enables, alarm inputs, relay controls, or status indicators, and the 2.3 V to 5.5 V range supports common embedded rails. The I2C/SMBus connection keeps the physical bus compact, while reset helps initialize the port state. Check signal levels and timing carefully in the final design.
推荐
Push-Button and Indicator Handling
The PCA9538PWR can consolidate push-button inputs and front-panel indicators behind a two-wire serial interface. Eight GPIO lines can be assigned to user controls, LEDs, status flags, or panel indicators, depending on the port configuration. The interrupt function lets the host react to selected input changes instead of polling every button continuously. Confirm the port modes and any external pull-up requirements in the datasheet, then validate debounce and indicator drive current in firmware and hardware testing.
推荐
Industrial Control Module
The PCA9538PWR is appropriate for compact industrial control modules that need distributed digital I/O without dedicating multiple host pins. The 8-bit port count supports a mix of discrete inputs and outputs, while the 2.3 V to 5.5 V range accommodates common control rails. Its interrupt and reset functions help organize event-driven firmware and startup sequencing. Industrial qualification, transient immunity, and environmental requirements must be verified separately because those claims are not included in the supplied data.
推荐
Communication and Network Equipment
The PCA9538PWR can provide auxiliary status, reset, enable, and alarm lines in communication equipment where the main processor has limited spare GPIO. The serial I2C/SMBus interface is useful in network-control boards because it connects the expander through a shared bus rather than a wide parallel harness. Interrupt can provide event notification, while reset supports controlled initialization. The designer must confirm bus pull-ups, address assignment, and all peripheral signal levels in the system schematic.
推荐
Power-Sequencing Support
The PCA9538PWR can be used for low-current power-sequencing and peripheral-enable signals when the sequence does not require high current or high voltage. Its eight configurable ports provide multiple discrete control points, and reset can establish a known startup state. The 2.3 V to 5.5 V range is useful for common logic rails, but the device should not be treated as a power switch without checking its output-drive limits and external transistor or load requirements. Use suitable level shifting when controlled signals exceed its specified range.
推荐
推荐产品汇总
工程参考数据： PCA9538PWR ——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 | PCA9538PWR |
|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors |
| Package | TSSOP-16 | TSSOP-16 |
| I/O Count | 8 bits | 8 bits |
| Operating Voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V |
| Interface | I2C-bus and SMBus | I2C-bus and SMBus |
| Bus Frequency | 400 kHz | 400 kHz |
| Interrupt | Yes | Yes |
| Reset | Yes | Yes |
关键差异点
- Eight-bit serial GPIO expansion （对比 PCA9557D)
- Integrated interrupt and reset functions （对比 TCA9538)
- Common 2.3 V to 5.5 V supply range （对比 Unqualified GPIO-expander alternatives)
设计说明
Route SCL and SDA as a compact two-wire bus and place the required pull-up resistors close to the bus nodes according to the system’s voltage and capacitance budget. Keep the PCA9538PWR TSSOP-16 footprint and pin orientation consistent with the official package drawing. Because the supplied data does not include the complete pin table, verify every net against the manufacturer datasheet before fabrication rather than relying on an inferred TSSOP pinout.
Decouple the PCA9538PWR supply with the recommended local capacitor arrangement from the manufacturer application guidance, and keep the power return path short. The verified operating range is 2.3 V to 5.5 V, but input voltage, output voltage, current limits, and absolute maximum ratings must be checked in the datasheet for the actual port loads. Do not use the expander as a high-current power switch without an appropriate external driver.
A common integration mistake is treating every port as an output or assuming that an I2C address is interchangeable across different expanders. Confirm port direction, pull-up configuration, address selection, interrupt masking, reset behavior, and host firmware register sequencing. Also verify that downstream devices tolerate the selected logic level. The verified sources identify the functions but do not provide all electrical and timing details, so the official datasheet is the design authority.
合规信息
The supplied manufacturer and distributor snippets identify the product and package but do not state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. These fields remain unknown rather than being inferred.
