1 MHz I2C I/O expander with POR
The NXP PCA9670PW,118 is an 8-bit I2C I/O expander clocked at 1 MHz, providing eight push-pull output lines for general-purpose digital expansion in embedded systems.
Output drive and interrupt handling
Each I/O can sink 25 mA or source 100 µA — the sink current is enough to drive an LED directly, but the source side is weak, so pull-ups or external drivers are needed for high-side loads. There is no interrupt output pin on this expander — the host must poll the I2C bus to detect input changes, which matters for latency-sensitive applications where an interrupt-driven part like the PCA9671 would be a better fit. The built-in Power-On Reset (POR) ensures the outputs default to a known state after power-up, eliminating the need for an external reset supervisor in many designs.