I²C GPIO expander for board-level I/O scaling
The NXP PCA9671PW,118 is a 16-bit I²C GPIO expander in a 24-TSSOP package, providing push-pull outputs and a 1 MHz clock interface for adding digital I/O to a microcontroller or SoC without extra pin allocation.
Output drive and power-up behaviour
Each I/O pin can source 100 µA or sink 25 mA, so the push-pull outputs drive LEDs, small relays, or logic inputs directly — the sink current is the practical limit for driving loads without an external transistor. No interrupt output is provided — the host must poll the expander over I²C to detect input changes, which is acceptable for low-frequency monitoring or when the bus is already scanned periodically.
Package and board-fit for reflow assembly
The surface-mount package is RoHS3 compliant and rated for industrial temperature profiles — store the reels dry per JEDEC MSL level, as TSSOP packages are moisture-sensitive.