NXP Semiconductors PCA9554APW,112

Overview

PCA9554APW,112 from NXP Semiconductors is an 8-bit I²C-bus/SMBus GPIO expander in TSSOP16 package, supporting 2.3 V to 5.5 V supply, 5 V-tolerant I/Os, and 400 kHz clock frequency. It provides configurable input/output pins, polarity inversion, active-low open-drain interrupt output, and internal power-on reset - used for expanding I/O in ACPI power switches, LED/fan control, sensor interfaces, and push-button monitoring.

For engineers reviewing the PCA9554APW,112 datasheet, PCA9554APW,112 pinout, PCA9554APW,112 application, or PCA9554APW,112 equivalent, key selection criteria include I²C address compatibility (0x70–0x77), interrupt-driven input change detection, 5 V I/O tolerance with 2.3 V minimum VDD, low standby current (≤1 µA at VDD=5.5 V, VI=VDD), and register-level polarity inversion for flexible signal conditioning.

Technical Context

The PCA9554APW,112 implements a synchronous I²C slave interface with fixed 7-bit address 0x70 (0111000X) determined by A2–A0 pins, distinct from PCA9554's 0x20 (0100000X). Its register map includes Input Port (read-only), Output Port (read/write), Polarity Inversion (read/write), and Configuration (read/write) registers - all accessible via command byte addressing without auto-increment.

Each of its eight bidirectional I/O pins defaults to high-impedance input with 100 kΩ internal pull-up at power-on reset. When configured as outputs, they support ±10 mA sink/source per pin (VOL ≤ 0.7 V at VDD = 3.0 V), while inputs tolerate up to 5.5 V independent of VDD. The open-drain INT pin asserts low when any input state differs from its Input Port register value.

Key Specifications

Pinout & Package

TSSOP16 package (SOT403-1): plastic thin shrink small outline, 16 leads, 4.4 mm body width, 0.65 mm pitch, exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C GPIO expander applications.

Compared with PCA9554PW,112, PCA9554APW,112 offers distinct bus addressing to avoid conflicts in mixed-family systems; versus TCA6408AIPWR, it retains polarity inversion for flexible signal alignment but trades off reset pin availability and peak output current.

Availability

PCA9554APW,112 is available at Aetrix Electronics and suitable for industrial control panels, smart HVAC thermostats, and LED status indicator arrays requiring stable component supply across extended production lifecycles.

Supply support for PCA9554APW,112 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The PCA9554A product line delivers I²C-based GPIO expansion with enhanced drive, 5 V tolerance, and interrupt capability - designed specifically for space-constrained, low-power embedded systems needing reliable peripheral interface extension.

FAQ

What is the fixed I²C slave address of PCA9554APW,112?

The PCA9554APW,112 has a fixed 7-bit I²C slave address of 0x70 (0111000X), where the least significant bit is the R/W bit. Address bits A2–A0 (pins 3, 2, 1) allow selection of one of eight possible addresses (0x70–0x77) on the same bus. This differs from the PCA9554 series (0x20–0x27), enabling coexistence of both families on a single I²C bus.

Does PCA9554APW,112 support 5 V logic levels on its I/O pins when VDD is 3.3 V?

Yes, PCA9554APW,112 supports 5 V-tolerant I/Os - input and output pins can withstand up to 5.5 V regardless of VDD level (2.3 V to 5.5 V). When VDD = 3.3 V, IO0–IO7 may safely interface with 5 V peripherals without external level shifters, simplifying mixed-voltage system design.

How does the interrupt output (INT) of PCA9554APW,112 behave during power-up?

At power-on reset, the PCA9554APW,112 initializes all registers to default values: Configuration register sets all I/Os as inputs, Input Port register reflects actual pin states, and INT remains deasserted until an input state change occurs. No false interrupt is generated at POR because the Input Port register is updated after initialization completes.

Can PCA9554APW,112 drive LEDs directly, and what is the maximum sink current per I/O pin?

Yes, PCA9554APW,112 can drive LEDs directly when configured as outputs. Each I/O pin supports up to 10 mA sink current (VOL ≤ 0.7 V at VDD = 3.0 V) and 8 mA source current (VOH ≥ 2.5 V at VDD = 3.0 V). Total sourced current across all pins must not exceed 85 mA, and total device current must remain below 100 mA.

Is there a polarity inversion function in PCA9554APW,112, and how is it implemented?

Yes, PCA9554APW,112 includes a dedicated 8-bit Polarity Inversion register (Register 2). Writing '1' to any bit inverts the corresponding bit in the Input Port register readback - enabling active-HIGH or active-LOW interpretation of the same physical input signal without firmware XOR operations. This feature is fully implemented in PCA9554APW,112 and requires no external components.