NXP Semiconductors PCA9673DB,118

Overview

PCA9673DB,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 interrupt and hardware reset functionality. It operates from 2.3 V to 5.5 V, supports 1 MHz I²C-bus speed, delivers 25 mA sink per I/O, and features 400 mA total package sink capacity-enabling direct LED PWM dimming in signage and industrial control panels.

For engineers reviewing the PCA9673DB,118 datasheet, PCA9673DB,118 pinout, PCA9673DB,118 application, or PCA9673DB,118 equivalent, this device serves as a drop-in upgrade over PCF8575 with higher bus speed, stronger drive, expanded address space (16 options), and active-low RESET replacing A2-critical for robust embedded I/O management where bus loading, timing-critical LED control, and fault-recovery sequencing matter.

Technical Context

The PCA9673DB,118 implements a latch-based quasi-bidirectional I/O architecture with internal Power-On Reset (POR) and dedicated active-low RESET input, enabling deterministic initialization without external circuitry. Its I²C interface complies with Standard- and Fast-mode Plus specifications, supporting 1 MHz operation on buses up to 4000 pF with 30 mA SDA sink capability.

Each of its 16 I/Os defaults to high-impedance input at power-up and supports latched output mode with 25 mA sink per pin; the open-drain INT output asserts on any port edge change and clears automatically upon read/write access or port state restoration-eliminating polling overhead in microcontroller systems.

Key Specifications

Pinout & Package

PCA9673DB,118 is supplied in a 24-pin SOIC package (SO24, SOT137-1), 7.5 mm body width, with gull-wing leads and standard JEDEC outline. Pin numbering follows conventional SOIC orientation with pin 1 index marker at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9674DB,118, PCA9673DB,118 provides hardware RESET for fail-safe initialization but requires external AD0/AD1 biasing; versus PCF8575T/3,118, it delivers 2.5× bus speed, 4× sink capacity, and integrated interrupt/reset-making it essential for responsive, high-density I/O systems.

Availability

PCA9673DB,118 is available at Aetrix Electronics and suitable for LED signage, industrial PLCs, and medical equipment requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for PCA9673DB,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 ecosystem components and embedded interface IP.

The PCA9673DB,118 belongs to NXP's Fast-mode Plus I²C remote I/O expander product line, designed specifically for high-reliability embedded systems needing deterministic reset, interrupt-driven I/O management, and scalable bus topology without performance bottlenecks.

FAQ

What is the maximum I²C-bus speed supported by the PCA9673DB,118?

The PCA9673DB,118 supports Fast-mode Plus (Fm+) I²C operation at up to 1 MHz-2.5× faster than standard Fast-mode devices. This speed enables rapid LED PWM updates and low-latency sensor data acquisition. The PCA9673DB,118 achieves this with 30 mA SDA sink capability, allowing reliable communication on heavily loaded buses up to 4000 pF without external bus buffers.

Does the PCA9673DB,118 include a hardware reset function?

Yes, the PCA9673DB,118 features an active-low RESET input pin that asynchronously resets all internal registers and the I²C-bus state machine to their power-up defaults. This hardware reset is independent of bus activity and complements the internal Power-On Reset (POR). The PCA9673DB,118 requires the RESET pin to be held LOW for a minimum duration (t_w(rst)) to ensure proper initialization-critical for fail-safe recovery in industrial control systems.

How many I²C slave addresses does the PCA9673DB,118 support?

The PCA9673DB,118 supports 16 programmable slave addresses using the AD0 and AD1 address pins. These pins accept binary inputs (VDD/VSS) to select one of 16 unique 7-bit addresses ranging from 0x28 to 0x5E in hexadecimal. The PCA9673DB,118 excludes reserved I²C addresses (e.g., General Call 0x00 and Device ID 0xF8), ensuring compatibility in multi-device networks without address conflicts.

Can the PCA9673DB,118 directly drive LEDs?

Yes, the PCA9673DB,118 can directly drive LEDs with up to 25 mA sink current per I/O pin and 400 mA total package sink capacity. Its quasi-bidirectional ports default to inputs at power-up and support latched output mode-allowing sustained LED current without continuous MCU intervention. The PCA9673DB,118's 1 MHz I²C interface enables precise PWM dimming control, making it suitable for LED signage, status indicators, and backlight management.

What is the purpose of the INT pin on the PCA9673DB,118?

The INT pin on the PCA9673DB,118 is an active-low open-drain interrupt output that signals port state changes (rising or falling edges) to the host microcontroller. It eliminates polling overhead by allowing the MCU to enter low-power sleep until an I/O event occurs. The PCA9673DB,118 automatically deasserts INT upon reading or writing the affected port-or when the port returns to its original logic level-ensuring clean, self-clearing event notification.