NXP Semiconductors PCA9674APW,112

Overview

PCA9674APW,112 from NXP Semiconductors is an 8-bit remote I/O expander for Fast-mode Plus (Fm+) I²C-bus with interrupt output, operating from 2.3 V to 5.5 V, supporting 1 MHz data transfer, 25 mA per port sink drive for direct LED control, and active-low open-drain INT pin for change-of-state notification. It is used in LED signage, industrial PLCs, and keypad interfaces where space-constrained I²C expansion is required.

For engineers reviewing the PCA9674APW,112 datasheet, PCA9674APW,112 pinout, PCA9674APW,112 application, or PCA9674APW,112 equivalent, key selection criteria include Fm+ I²C compatibility (1 MHz), quasi-bidirectional I/O behavior, interrupt-driven input monitoring, 25 mA per-port sink capability, and TSSOP16 package suitability for high-density PCB layouts.

Technical Context

The PCA9674APW,112 implements a quasi-bidirectional I/O architecture with no direction register-each of the eight ports (P0–P7) defaults to input at power-up with a 100 µA weak pull-up, and functions as either input or output based on write value (1 = input/high-impedance, 0 = active-low output). The internal Power-On Reset initializes all I/Os as inputs.

Its interrupt logic asserts the active-low open-drain INT pin when any input state differs from its corresponding port register value, enabling efficient event-driven polling. The device supports Software Reset via General Call address (00h) + data byte 06h and provides a 24-bit read-only Device ID (manufacturer: NXP, part ID: 001001011, revision: 000).

Key Specifications

Pinout & Package

TSSOP16 package (SOT403-1), 4.4 mm body width, 16-pin surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I/O expander applications.

Compared with PCA9674PW,112 and PCA9674AD,512, the PCA9674APW,112 offers optimal balance of high-density packaging (TSSOP16), non-overlapping I²C addressing (62 slots), and industrial temperature support - making it preferred for new designs targeting space-constrained, multi-node I²C systems.

Availability

PCA9674APW,112 is available at Aetrix Electronics and suitable for LED signage, industrial PLCs, and medical keypad interfaces requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for PCA9674APW,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 PCA9674/74A product line was designed to deliver scalable, interrupt-capable I/O expansion for resource-constrained microcontrollers - enabling reliable peripheral control in industrial automation, medical instrumentation, and consumer electronics with minimal firmware overhead.

FAQ

What is the I²C bus speed supported by the PCA9674APW,112?

The PCA9674APW,112 supports Fast-mode Plus (Fm+) I²C operation at up to 1 MHz. This higher speed enables faster I/O updates compared to standard Fast-mode (400 kHz), improving responsiveness in time-critical applications like LED PWM dimming and real-time input monitoring. The SDA line sustains 30 mA sink current to drive heavily loaded buses up to 4000 pF without external buffers.

How does the quasi-bidirectional I/O architecture work in the PCA9674APW,112?

The PCA9674APW,112 uses quasi-bidirectional I/Os with no dedicated direction register: writing '1' configures a port as input (with 100 µA weak pull-up to VDD), while writing '0' activates a 25 mA sink transistor for output-low. At power-up, all ports default to input-high. This architecture simplifies firmware, reduces memory usage, and enables simultaneous input sampling and output control using a single 8-bit register.

What is the purpose of the INT pin on the PCA9674APW,112?

The INT pin on the PCA9674APW,112 is an active-low open-drain interrupt output that asserts whenever the state of any input port (P0–P7) differs from its corresponding bit in the input port register. This allows the host microcontroller to respond to input changes asynchronously, eliminating continuous polling and reducing CPU load - especially valuable in low-power and real-time embedded systems.

Can the PCA9674APW,112 drive LEDs directly?

Yes, the PCA9674APW,112 can drive LEDs directly: each of its eight I/O ports provides 25 mA sink current capability in output mode, sufficient for standard indicator LEDs. With proper current-limiting resistors connected between VDD and the LED anode, the PCA9674APW,112 sinks current through the cathode to turn the LED on. Total package sink capacity is 200 mA, allowing multiple LEDs to be driven concurrently.

What are the key differences between PCA9674APW,112 and PCA9674PW,112?

The PCA9674APW,112 and PCA9674PW,112 share identical pinout, electrical specs, and TSSOP16 packaging, but differ in I²C slave address mapping: PCA9674APW,112 implements the PCA9674A address set (62 addresses, excluding General Call 00h and Device ID F8h), while PCA9674PW,112 uses the PCA9674 map (64 addresses). They are not address-compatible and cannot coexist on the same I²C bus without conflict.