NXP Semiconductors PCA9675D,118

Overview

PCA9675D,118 from NXP Semiconductors is a 16-bit remote I/O expander for Fast-mode Plus (Fm+) I²C-bus systems, providing quasi-bidirectional port expansion with 25 mA per pin sink capability, 1 MHz I²C clock support, and active-low open-drain interrupt output. It operates from 2.3 V to 5.5 V, supports 64 programmable slave addresses, and is used in LED signage, industrial PLCs, and server management subsystems.

For engineers reviewing the PCA9675D,118 datasheet, PCA9675D,118 pinout, PCA9675D,118 application, or PCA9675D,118 equivalent, this device delivers high-drive I/O expansion with interrupt-driven event notification, Fm+ bus compatibility, and robust thermal performance in SO24 packaging - critical for space-constrained embedded control and LED dimming designs.

Technical Context

The PCA9675D,118 implements a latch-based quasi-bidirectional I/O architecture where all 16 pins (P00–P07, P10–P17) default to HIGH inputs at power-up and support independent directionless read/write via I²C. Its internal Power-On Reset (POR) and software reset (via General Call 00h + 06h) ensure deterministic initialization without external circuitry.

It features an active-low open-drain INT pin that asserts on any input edge change, enabling microcontroller wake-up without polling. The SDA line provides 30 mA sink drive for 4000 pF bus loads, while total package sink capacity reaches 400 mA - sufficient to drive all 16 outputs simultaneously at 25 mA each.

Key Specifications

Pinout & Package

PCA9675D,118 is supplied in plastic small outline package (SO24), 24-lead, 7.5 mm body width (SOT137-1), with exposed pad not present. Pin 1 is INT; pins 2–3 are AD1/AD2; pins 4–11 and 13–20 are I/Os P00–P07 and P10–P17; pin 12 is VSS; pin 21 is AD0; pin 22 is SCL; pin 23 is SDA; pin 24 is VDD.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9674D,118 and PCF8575CD,118, the PCA9675D,118 delivers double the I/O count, 3.3× higher I²C bandwidth, 4× greater total sink current, and diagnostic capabilities (Device ID, software reset) essential for modern embedded control and serviceability.

Availability

PCA9675D,118 is available at Aetrix Electronics and suitable for LED signage, industrial PLCs, and server management systems requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.

Supply support for PCA9675D,118 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 deep expertise in I²C peripheral IP and robust mixed-signal design.

The PCA9675D,118 belongs to NXP's Fast-mode Plus I²C I/O expander product line, engineered specifically for high-density, interrupt-driven remote control in space- and power-constrained embedded systems.

FAQ

What is the maximum I²C clock frequency supported by the PCA9675D,118?

The PCA9675D,118 supports Fast-mode Plus (Fm+) I²C operation up to 1 MHz. This is confirmed in the NXP datasheet Rev. 2 (2011), Section 2 "Features and benefits", and enables faster LED PWM updates and reduced bus arbitration time versus standard 400 kHz Fast-mode devices. The PCA9675D,118 maintains full timing compliance across its 2.3 V to 5.5 V supply range.

Does the PCA9675D,118 require external pull-up resistors on SDA and SCL lines?

Yes, the PCA9675D,118 requires external pull-up resistors on both SDA and SCL lines, as specified in Section 9 "Characteristics of the I²C-bus". SDA has 30 mA sink capability supporting 4000 pF bus loads, but pull-ups remain mandatory for proper open-drain bus operation. Typical values are 2.2 kΩ for 3.3 V systems and 4.7 kΩ for 5 V systems.

How does the interrupt (INT) pin on the PCA9675D,118 behave during I/O state changes?

The INT pin on the PCA9675D,118 is an active-low open-drain output that asserts whenever any rising or falling edge occurs on any input-capable I/O pin (P00–P07, P10–P17). As described in Section 8.5, the interrupt deasserts automatically after a read or write transaction to the device, or when the port state reverts to its prior value - eliminating need for manual clearing in firmware.

Can the PCA9675D,118 drive LEDs directly without external transistors?

Yes, the PCA9675D,118 can drive standard LEDs directly: each of its 16 quasi-bidirectional I/O pins supports 25 mA sink current, and the total package sink capacity is 400 mA. This is explicitly stated in Section 2 "Features and benefits" and validated in the functional description. For common-anode LED configurations, connect LED anodes to VDD and cathodes to PCA9675D,118 I/O pins.

What is the purpose of the Device ID feature in the PCA9675D,118?

The Device ID feature in the PCA9675D,118 provides a 24-bit read-only identifier containing manufacturer code (8 bits), part identification (13 bits), and die revision (3 bits), accessible via reserved I²C address 0xF4 (1111 100b). As detailed in Section 7.2.2, it enables firmware-level silicon verification, field diagnostics, and calibration traceability - critical for production test and maintenance workflows involving PCA9675D,118.