NXP Semiconductors PCA9672D,512

Overview

PCA9672D,512 from NXP Semiconductors is an 8-bit remote I/O expander IC for Fast-mode Plus (Fm+) I²C-bus systems, operating from 2.3 V to 5.5 V with 5.5 V-tolerant I/Os. It provides quasi-bidirectional ports (P0–P7), 1 MHz I²C interface, active LOW open-drain interrupt (INT), and active LOW hardware reset (RESET). It directly drives LEDs with 25 mA sink per port and supports up to 128 I/Os via 16 configurable slave addresses - used in LED signage, industrial PLCs, and keypad interfaces.

For engineers reviewing the PCA9672D,512 datasheet, PCA9672D,512 pinout, PCA9672D,512 application, or PCA9672D,512 equivalent, key selection considerations include its Fm+ I²C compatibility (1 MHz), 25 mA per-port sink capability, 2.5 µA static current, SO16 package footprint, and interrupt-driven input monitoring without polling.

Technical Context

The PCA9672D,512 implements a single-register quasi-bidirectional I/O architecture with no direction register: writing '1' configures a port as input (weak 100 µA pull-up to VDD), writing '0' enables strong 25 mA sink output. Its interrupt logic asserts INT (active LOW) on any input state change versus register value, enabling event-driven microcontroller wake-up.

It supports Fast-mode Plus I²C (1 MHz) with 30 mA bus drive strength, allowing longer traces or more devices without buffers. Addressing uses two hardware pins (AD0/AD1) to select among 16 slave addresses, and includes software reset (00h + 06h sequence) and read-only 24-bit device ID (manufacturer, part ID, revision).

Key Specifications

Pinout & Package

PCA9672D,512 is housed in a 16-lead SOIC (SO16) package (SOT162-1), 7.5 mm body width, standard JEDEC outline, RoHS-compliant, and rated for −40 °C to +85 °C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9674D,512, the PCA9672D,512 offers optimal channel density for space-constrained designs requiring precise 8-bit expansion; versus TCA6408APWR, it delivers higher drive strength, deterministic interrupt behavior, and enhanced system visibility via device ID and software reset - critical for industrial and medical deployments.

Availability

PCA9672D,512 is available at Aetrix Electronics and suitable for LED signage, industrial PLCs, and medical keypad interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for PCA9672D,512 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 leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with deep expertise in I²C peripherals and embedded interface IP.

The PCA9672D,512 belongs to NXP's remote I/O expander product line, designed specifically for low-power, interrupt-driven peripheral expansion in resource-constrained embedded systems using standard I²C infrastructure.

FAQ

What is the maximum I²C bus speed supported by the PCA9672D,512?

The PCA9672D,512 supports Fast-mode Plus (Fm+) I²C operation up to 1 MHz. This enables high-speed communication for time-critical functions such as PWM-based LED dimming and rapid input state polling. The 30 mA I²C bus drive capability allows more devices on the same bus without external buffers, making it ideal for dense I²C networks where the PCA9672D,512 serves as a scalable I/O node.

How does the quasi-bidirectional I/O architecture of the PCA9672D,512 differ from standard GPIO expanders?

Unlike conventional expanders requiring separate direction registers, the PCA9672D,512 uses a single data register where writing '1' configures the port as an input (with 100 µA weak pull-up) and writing '0' enables strong 25 mA sink output. This eliminates direction register writes, reduces I²C traffic, and simplifies firmware - especially valuable in memory-constrained microcontrollers interfacing with the PCA9672D,512.

Can the PCA9672D,512 drive LEDs directly without external components?

Yes - each of the eight I/O ports (P0–P7) on the PCA9672D,512 provides 25 mA sink current, and the total package sink capability is 200 mA. When paired with appropriate current-limiting resistors connected between VDD and the LED anode, the PCA9672D,512 can directly drive standard indicator LEDs without transistors or driver ICs - a key advantage in space- and BOM-sensitive designs using the PCA9672D,512.

What happens to the I/O ports during power-on or hardware reset of the PCA9672D,512?

Upon power-on or assertion of the active LOW RESET pin, the PCA9672D,512 initializes all eight I/O ports (P0–P7) as inputs with a weak 100 µA internal pull-up to VDD. This default safe state prevents bus contention and ensures predictable startup behavior - critical for reliable operation in systems where the PCA9672D,512 manages critical indicators or sensors before firmware initialization.

Does the PCA9672D,512 support software-initiated reset, and how is it executed?

Yes - the PCA9672D,512 supports software reset via the I²C General Call address (00h) followed by data byte 06h. This sequence resets all registers to power-on defaults without requiring physical RESET pin toggling. It is particularly useful for recovering hung I²C nodes or synchronizing multiple PCA9672D,512 devices in a system - a capability not found in many competing I/O expanders.