NXP Semiconductors PCA9554N,112

Overview

PCA9554N,112 from NXP Semiconductors is an 8-bit I²C-bus/SMBus GPIO expander in SO16 package, providing configurable input/output pins, active-low open-drain interrupt output, polarity inversion register, and 5 V-tolerant I/Os operating from 2.3 V to 5.5 V supply. It serves as a peripheral expansion interface for microcontrollers in industrial control panels requiring push-button sensing, LED status indication, and fan monitoring.

For engineers reviewing the PCA9554N,112 datasheet, PCA9554N,112 pinout, PCA9554N,112 application, or PCA9554N,112 equivalent, key selection criteria include I²C address configurability via A0–A2 pins, 400 kHz fast-mode support, low standby current (≤700 µA), interrupt-driven input change detection, and compatibility with legacy PCF8574 software after register mapping updates per AN469.

Technical Context

The PCA9554N,112 implements a synchronous I²C slave interface with four internal registers-Configuration, Input Port, Output Port, and Polarity Inversion-each accessible via command byte addressing. Its I/O direction is fully software-configurable per bit, and all I/Os default to high-impedance inputs with weak pull-ups at power-on reset.

Interrupt generation is edge-sensitive and triggered only when an input pin's logic level differs from its corresponding Input Port register value. The device includes noise filtering on SCL/SDA lines, ESD protection exceeding 2000 V HBM, and latch-up immunity per JEDEC JESD78 (>100 mA).

Key Specifications

Pinout & Package

PCA9554N,112 is supplied in SO16 (SOT162-1) package: plastic small outline, 16-pin, 7.5 mm body width, standard lead pitch of 1.27 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9554N,112, PCA9554PW,112 offers 42 % smaller footprint but requires finer-pitch assembly, while PCA9554DB,112 provides 23 % lower profile and enhanced thermal resistance-both retain full register compatibility and interrupt behavior.

Availability

PCA9554N,112 is available at Aetrix Electronics and suitable for industrial control panels, smart thermostats, and automotive body controllers requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for PCA9554N,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 markets.

The PCA9554N,112 belongs to NXP's I²C-bus I/O expander product line, designed specifically to simplify peripheral expansion in resource-constrained embedded systems while maintaining industrial-grade reliability and interoperability.

FAQ

What is the default I/O configuration of PCA9554N,112 at power-on reset?

At power-on reset, all eight I/O pins (IO0–IO7) of the PCA9554N,112 default to high-impedance inputs with internal weak pull-up resistors (~100 kΩ to VDD). The Configuration register bits are set to '1', the Output Port register defaults to 0xFF, and the Polarity Inversion register is cleared to 0x00-ensuring glitch-free initialization without external intervention.

Does PCA9554N,112 support 400 kHz I²C communication?

Yes, the PCA9554N,112 fully supports Fast-mode I²C operation up to 400 kHz, as confirmed in its dynamic characteristics table. It meets timing requirements including tLOW (≥1.3 µs), tHIGH (≥0.6 µs), and tf/tr limits for standard and fast modes-enabling high-throughput GPIO register access in time-critical applications.

Can PCA9554N,112 interface directly with 5 V logic while powered from 3.3 V?

Yes, the PCA9554N,112 features 5 V-tolerant I/O pins, allowing direct connection to 5 V signal sources (e.g., switches, sensors, LEDs) even when VDD is supplied at 3.3 V. This eliminates external level-shifting circuitry and simplifies mixed-voltage system design without compromising signal integrity or device safety.

How does the interrupt output (INT) of PCA9554N,112 behave during I/O reconfiguration?

The INT pin of PCA9554N,112 may assert a false interrupt when an I/O pin is reconfigured from output to input if its external voltage level differs from the stored value in the Input Port register. To avoid this, read the Input Port register immediately before changing the Configuration register, or ensure external pin states match expected values prior to direction change.

Is PCA9554N,112 pin-compatible with the PCF8574 series?

The PCA9554N,112 is pin-to-pin compatible with the PCF8574 series in SO16, SSOP16, and TSSOP16 packages and shares the same base I²C address range (0x20–0x27). However, software must be updated to accommodate additional registers (Polarity Inversion, Configuration) and revised command byte protocol-details are provided in Application Note AN469.