16-bit I/O expansion over two wires
The PCF8575RGER is a 16-bit I/O expander from Texas Instruments that adds 16 general-purpose I/O pins to any I²C or SMBus host — no extra GPIO bank needed on the MCU. Communication runs at up to 400 kHz on the I²C bus, which keeps the pin count on the controller side to just SDA and SCL while the expander handles the parallel I/O locally. Each I/O is push-pull, sourcing 1 mA and sinking 25 mA per pin — enough to drive LEDs directly or interface with logic-level loads without external buffers.
Package and board-fit for dense layouts
Housed in a 24-VFQFN with exposed pad (4x4 mm body per the supplier device package 24-VQFN), the PCF8575RGER suits space-constrained designs where every square millimeter counts.
Power-on reset and interrupt for deterministic control
A built-in power-on reset (POR) circuit initialises all I/O registers to a known state at power-up, eliminating the need for a software reset sequence after each supply cycle. An interrupt output pin (INT) signals the host when any input changes state — the firmware can sleep the main controller and wake only on a pin transition, reducing average current draw in battery-powered or low-power systems.
Active production and sourcing posture
For volume commitments, a multi-year supply agreement can be structured through the independent distribution desk.