NXP Semiconductors PCA9672D,518

Overview

PCA9672D,518 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 features eight quasi-bidirectional ports, 1 MHz I²C interface, active LOW open-drain interrupt (INT), active LOW hardware reset (RESET), and 25 mA per-pin sink capability-enabling direct LED drive in industrial control panels and server status indicators.

For engineers reviewing the PCA9672D,518 datasheet, PCA9672D,518 pinout, PCA9672D,518 application, or PCA9672D,518 equivalent, key selection considerations include its Fm+ bus compatibility, 2.5 µA standby current, 16 configurable slave addresses via AD0/AD1, latch-up immunity (>100 mA), and ESD robustness (2000 V HBM).

Technical Context

The PCA9672D,518 implements a single-register quasi-bidirectional I/O architecture with no direction register-each port defaults to input at power-up with a 100 µA weak pull-up to VDD. Input state changes trigger an active LOW INT signal, eliminating polling overhead in microcontroller-based monitoring systems.

Its I²C interface supports Fast-mode Plus (1 MHz) with 30 mA bus drive strength, enabling longer trace lengths or higher node counts without external buffers. The device includes both hardware RESET and software reset via General Call address 00h + data byte 06h, plus read-only Device ID (24-bit) for automated BOM verification.

Key Specifications

Pinout & Package

PCA9672D,518 is supplied in SO16 (SOT162-1) package: plastic small outline, 16 leads, 7.5 mm body width, surface-mount, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C I/O expander applications.

Compared with PCA9555D,118 and TCA6408APWR, the PCA9672D,518 uniquely combines Fm+ speed, interrupt signaling, software reset, and Device ID in a single SO16 package-making it optimal for time-critical, field-serviceable, and audit-ready embedded systems.

Availability

PCA9672D,518 is available at Aetrix Electronics and suitable for industrial control, server management, and medical instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for PCA9672D,518 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 focused on secure connectivity solutions for automotive, industrial, and IoT applications, with core expertise in interface, power management, and embedded processing.

The PCA9672D,518 belongs to NXP's I²C I/O expander product line, designed specifically for robust, low-power remote I/O expansion in harsh environments-emphasizing interrupt-driven responsiveness, ESD resilience, and seamless integration with ARM Cortex-M and RISC-V host controllers.

FAQ

What is the maximum I²C bus speed supported by the PCA9672D,518?

The PCA9672D,518 supports Fast-mode Plus (Fm+) I²C operation up to 1 MHz. This is confirmed in the NXP datasheet Rev. 3 (27 May 2013), Section 2 "Features and benefits", and enables high-speed LED PWM dimming and reduced host polling latency. The 30 mA bus drive strength allows longer traces or more nodes without repeaters-critical for dense server backplanes and industrial control cabinets where the PCA9672D,518 is deployed.

How does the PCA9672D,518 handle interrupt generation for input changes?

The PCA9672D,518 asserts its active LOW open-drain INT pin whenever any of its P0–P7 input states differ from their corresponding register values-detecting both rising and falling edges. As stated in Section 8.5, the interrupt resets to HIGH after reading or writing the port register, or when the input returns to its prior state. This behavior eliminates continuous polling and is validated in Figure 15 and timing diagram Figure 14 of the PCA9672D,518 datasheet.

Can the PCA9672D,518 directly drive LEDs, and what is its per-pin current capability?

Yes-the PCA9672D,518 can directly drive LEDs with 25 mA sink current per port (P0–P7), as specified in Section 2 "Features and benefits" and Table 7 "DC characteristics". Its quasi-bidirectional architecture uses a strong n-channel transistor to ground while relying on external VDD + current-limiting resistors on the LED anode side. Total package sink capability is 200 mA, allowing simultaneous drive of eight standard indicator LEDs without thermal derating-verified in thermal characterization data of the SO16 package.

What are the valid I²C slave address options for the PCA9672D,518?

The PCA9672D,518 supports 16 programmable slave addresses determined by AD0 and AD1 pin states (VDD, VSS, SDA, or SCL), as detailed in Table 4 "PCA9672 address map". Valid 7-bit addresses range from 20h to 57h (hex), excluding reserved I²C addresses. Each combination yields distinct write/read pairs (e.g., AD0=VSS, AD1=VSS → write 20h, read 21h). This enables up to 16 PCA9672D,518 devices on one bus-scaling to 128 I/O lines without address conflict.

Does the PCA9672D,518 include a software reset function, and how is it triggered?

Yes-the PCA9672D,518 implements a software reset via the I²C General Call address. As defined in Section 7.2.1, the sequence is: START → General Call address 00h (write) → ACK → data byte 06h → ACK → STOP. Upon successful execution, all registers revert to power-up defaults (I/Os as inputs with 100 µA pull-up). This feature is absent in many competing expanders and is critical for remote recovery in unattended systems using the PCA9672D,518.