PCA6408AHKX

The PCA6408AHKX is an 8-bit general purpose I/O expander that facilitates remote I/O expansion for microcontroller families through an I2C-bus interface. This NXP Semiconductors component offers a flexible solution for applications requiring additional I/Os, such as interfacing with sensors, push buttons, or keypads, particularly in battery-powered mobile devices. It simplifies interconnections and supports bidirectional voltage level translation, making it ideal for mixed-signal environments. The device features a wide VDD range of 1.65 V to 5.5 V, enabling seamless communication between low-voltage microprocessors and peripherals operating at different voltage levels. The PCA6408A includes configuration, input, output, and polarity inversion registers. At power-on, all I/Os are configured as inputs, but can be reconfigured as outputs by the system master. The device operates at clock frequencies up to 400 kHz and has an operating temperature range of -40°C to 85°C. It is supplied in a 16-XQFN package, suitable for surface mounting.

This I/O expander is designed to minimize interconnections and simplify system design. It features an open-drain interrupt output that signals the system master when an input state changes, without requiring constant communication over the I2C-bus. The PCA6408AHKX is built with a Power-On Reset (POR) feature. Its dual power rail capability, with VDD(I2C-bus) for the interface and VDD(P) for core circuits and Port P, further enhances its flexibility in diverse voltage environments. The device supports output currents of 10mA and 25mA.