NXP Semiconductors PCA9674D,512

Overview

PCA9674D,512 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 I²C data transfer, 25 mA per port sink drive for direct LED control, and active-low open-drain INT pin for change-of-state notification in embedded I/O expansion systems.

For engineers reviewing the PCA9674D,512 datasheet, PCA9674D,512 pinout, PCA9674D,512 application, or PCA9674D,512 equivalent, this device delivers deterministic quasi-bidirectional I/O behavior, hardware-addressable slave addressing (64 options), low standby current (4.5 µA typical), and integrated Power-On Reset - critical for reliable microcontroller peripheral extension in space-constrained industrial and mobile designs.

Technical Context

The PCA9674D,512 implements a single-register quasi-bidirectional I/O architecture where each of eight ports (P0–P7) functions as input or output without direction register overhead. Input states are monitored via weak 100 µA internal pull-up; outputs drive LOW with 25 mA sink capability and HIGH via accelerated 100 µA pull-up during ACK clock phase.

It features Fast-mode Plus I²C interface (1 MHz max), SDA bus drive strength up to 30 mA for 4000 pF loads, and interrupt logic that asserts INT when any input state differs from its corresponding register value - enabling efficient event-driven polling avoidance in host MCU firmware.

Key Specifications

Pinout & Package

PCA9674D,512 is supplied in SO16 (plastic small outline, 16-lead, 7.5 mm body width) package per SOT162-1 standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9674AD,512 and PCA9674PW,112, the PCA9674D,512 offers the broadest address flexibility (64 options) in the industry-standard SO16 package - making it optimal for general-purpose industrial and server I/O expansion where layout density and bus scalability are balanced priorities.

Availability

PCA9674D,512 is available at Aetrix Electronics and suitable for industrial control, medical equipment, and server rack management requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for PCA9674D,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 ICs.

The PCA9674D,512 belongs to NXP's remote I/O expander product line, designed specifically to extend microcontroller GPIO count over Fm+ I²C while minimizing firmware overhead, power, and board area in resource-constrained embedded systems.

FAQ

What is the maximum I²C bus speed supported by the PCA9674D,512?

The PCA9674D,512 supports Fast-mode Plus (Fm+) I²C operation up to 1 MHz. This is confirmed in the datasheet's General Description and Features sections, enabling faster I/O updates than standard Fast-mode (400 kHz) devices - critical for time-sensitive LED dimming and real-time status monitoring in the PCA9674D,512.

Does the PCA9674D,512 require external pull-up resistors on its I/O pins?

Yes - the PCA9674D,512 provides only a 100 µA internal weak pull-up on each quasi-bidirectional port (P0–P7) at power-up. For reliable input detection or stronger HIGH-level drive, external pull-up resistors are required. The datasheet explicitly states "no internal pull-up resistors are incorporated on AD2, AD1 or AD0" and confirms the same weak pull-up architecture applies to P0–P7 in Section 8.1.

How does the interrupt (INT) pin of the PCA9674D,512 operate?

The INT pin of the PCA9674D,512 is an active-low open-drain output that asserts when any input port state (P0–P7) differs from its corresponding bit in the input port register. It remains asserted until the host reads the port register, allowing the PCA9674D,512 to notify the MCU of asynchronous events without polling - a core feature documented in the General Description and Functional Description sections.

Can the PCA9674D,512 directly drive LEDs, and what is its current capability?

Yes - the PCA9674D,512 can directly drive LEDs with 25 mA sink current per port (P0–P7), and total package sink capability of 200 mA. This is specified in both the General Description ("latched output ports have 25 mA high current sink drive capability") and Features list, enabling common-anode LED configurations without external drivers.

What is the operating temperature range of the PCA9674D,512?

The PCA9674D,512 is rated for operation from −40 °C to +85 °C, as confirmed in the Features section and Ordering Information Table 2. This industrial-grade temperature range makes it suitable for deployment in servers, PLCs, and medical equipment where ambient conditions exceed commercial limits.