NXP Semiconductors PCA9674ATS,112

Overview

PCA9674ATS,112 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 bus speed, 25 mA per port sink drive for direct LED control, and active-low open-drain INT pin for change-of-state notification. It serves as a parallel port extension in microcontroller-based systems requiring scalable GPIO expansion.

For engineers reviewing the PCA9674ATS,112 datasheet, PCA9674ATS,112 pinout, PCA9674ATS,112 application, or PCA9674ATS,112 equivalent, this page delivers verified electrical specs, package mapping to TSSOP16, functional I/O behavior, interrupt logic timing, and real-world substitution guidance - all grounded in NXP's Rev. 7 product data sheet.

Technical Context

The PCA9674ATS,112 implements quasi-bidirectional I/O ports without direction registers: each of P0–P7 defaults to input at power-up with 100 µA weak pull-up, and supports independent assignment as input (monitoring keypads/interrupts) or output (driving LEDs). Its I²C interface complies with Fm+ (1 MHz), features 30 mA SDA sink capability for 4000 pF buses, and uses AD0–AD2 address pins to select one of 64 non-overlapping slave addresses.

Interrupt generation is edge-agnostic and level-sensitive: INT asserts low when any input pin state differs from its corresponding register value, eliminating polling overhead. Internal Power-On Reset initializes all I/Os as inputs, and Software Reset (via General Call 00h + 06h) restores default register states without hardware reset.

Key Specifications

Pinout & Package

PCA9674ATS,112 is supplied in a 16-pin TSSOP package (SOT403-1), 4.4 mm body width, lead-free and RoHS-compliant. Pin layout matches SO16 and HVQFN16 variants electrically but differs mechanically.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9674ATS,112, PCA9674PW,112 offers identical electrical and functional behavior with minor marking variation, while PCA9674D,518 provides the same core I/O expansion capability in a larger SO16 package - enabling trade-offs between density, thermal performance, and assembly method without sacrificing feature set or timing compliance.

Availability

PCA9674ATS,112 is available at Aetrix Electronics and suitable for LED signage control, industrial keypad interfaces, and server rack management requiring stable component supply, guaranteed long-term availability, and full traceability.

Supply support for PCA9674ATS,112 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.

The PCA9674 series belongs to NXP's I²C peripheral portfolio, designed specifically for scalable, low-power GPIO expansion in resource-constrained embedded systems with strict timing and reliability requirements.

FAQ

What is the I²C address range supported by PCA9674ATS,112?

The PCA9674ATS,112 supports 64 unique I²C slave addresses determined by AD0–AD2 pin configurations. These addresses span hex values 20h–3Fh, 40h–5Fh, A0h–BFh, and C0h–FFh (excluding reserved ranges). Each combination of AD0/AD1/AD2 ties to a specific 7-bit address, enabling up to 64 devices on one bus without conflict.

Does PCA9674ATS,112 require external pull-up resistors on SCL and SDA lines?

Yes, PCA9674ATS,112 requires external pull-up resistors on both SCL and SDA lines to ensure proper I²C bus operation. The device does not integrate internal pull-ups on these lines. Recommended values are 2.2 kΩ for 1 MHz Fm+ operation with typical bus capacitance; values must be adjusted based on actual bus load and rise-time requirements.

Can PCA9674ATS,112 drive LEDs directly without current-limiting resistors?

No, PCA9674ATS,112 cannot drive LEDs without external current-limiting resistors. While it provides 25 mA sink capability per port, the LED forward voltage and desired current must be controlled externally. A series resistor is mandatory to limit current to safe levels for both the LED and the PCA9674ATS,112 output stage.

How does the interrupt (INT) pin of PCA9674ATS,112 behave during power-up?

At power-up, the PCA9674ATS,112's INT pin is released (high-impedance) until the internal Power-On Reset completes and I/Os initialize. Once initialized, INT remains high (open-drain pulled up externally) unless an input state change occurs. No spurious assertion occurs during POR - the interrupt logic activates only after register initialization is complete.

Is PCA9674ATS,112 compatible with standard-mode (100 kHz) and fast-mode (400 kHz) I²C masters?

Yes, PCA9674ATS,112 is backward-compatible with standard-mode (100 kHz) and fast-mode (400 kHz) I²C masters. Its Fm+ interface fully supports lower speeds, and timing parameters meet or exceed those required for both modes. No configuration changes are needed - the device automatically adapts to the master's clock frequency.