PCA9538PW - 8-Bit I2C I/O Expander | NXP | TSSOP-16
MPN: PCA9538PW ✓ نشطPCA9538PW نظرة عامة
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 PCA9538PW. It also records sourced drop-in alternatives where the available evidence supports pin and package compatibility.
بدائل مباشرة لـ PCA9538PW — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع PCA9538PW (نفس عامل الشكل والبصمة) — يختلف في Package, Interface, Supply Voltage Range, Function, Interrupt Output.
لا تتوفر بدائل متوافقة تمامًا لهذا المنتج.
اطلب بدائلPCA9538PW المواصفات
| 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 |
| الواجهة | I2C-bus and SMBus |
| Bus Frequency | 400 kHz |
| Interrupt | Yes |
| Reset | Yes |
| Configuration Registers | Yes |
| Device Pin Count | 16 pins |
| العلبة | TSSOP-16 |
| نطاق درجة حرارة التشغيل | -40 C to +85 C |
| نوع التركيب | Surface mount |
| Interface Signals | SCL and SDA |
| Port Modes | Input, output, and high-impedance operation |
| Manufacturer | NXP Semiconductors |
دليل تكوين أطراف PCA9538PW tssop-16
تكوين الأطراف لـ PCA9538PW (حزمة tssop-16). يتم تعريف ترقيم الأطراف والوظائف ومخططات التوصيل في ورقة البيانات الفنية من الشركة المصنعة. راجعها للحصول على البصمة الدقيقة وإرشادات اللحام.
لا تتوفر بيانات مفصلة لمخطط التوصيلات لـ PCA9538PW.
راجع ورقة البيانات للحصول على تكوين الأطراف الكامل.
التطبيقات النموذجية
PCA9538PW مناسب لـ 6 التطبيقs: 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 PCA9538PW 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.
موصى به
Embedded Sensor Interfacing
The PCA9538PW 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.
موصى به
Push-Button and Indicator Handling
The PCA9538PW 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.
موصى به
Industrial Control Module
The PCA9538PW 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.
موصى به
Communication and Network Equipment
The PCA9538PW 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.
موصى به
Power-Sequencing Support
The PCA9538PW 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.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ PCA9538PW — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | PCA9538PW |
|---|---|---|
| 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 |
أبرز الفروقات
- Eight-bit serial GPIO expansion (مقابلPCA9557D)
- Integrated interrupt and reset functions (مقابلTCA9538)
- Common 2.3 V to 5.5 V supply range (مقابلUnqualified GPIO-expander alternatives)
ملاحظات التصميم
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 PCA9538PW 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 PCA9538PW 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.
معلومات الامتثال
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.
