NXP PCA9538D 8-bit I²C-bus and SMBus Low Power I/O Port with Interrupt

The PCA9538D is a highly versatile 8-bit I/O expander from NXP Semiconductors designed to provide additional I/O capabilities to microcontrollers over a two-wire I²C-bus or SMBus. This makes the device perfect for applications where pins on a microcontroller are at a premium, or when remote I/O expansion is necessary.

Built for low power consumption, the PCA9538D operates on a supply voltage range of 2.3V to 5.5V, allowing it to support both 3.3V and 5V logic. This makes it suitable for interfacing with a wide variety of logic families. The device features an active-low interrupt output which can be connected to the host microcontroller's interrupt input to indicate that an input state has changed, thus eliminating the need for the host to continuously poll the inputs.

The PCA9538D provides eight I/O pins that can be individually set as inputs or outputs. Configuring the device is straightforward, as it comes with an internal power-on reset, a hardware reset input, and an I²C-bus/SMBus address with a built-in fixed portion and a programmable portion to prevent address conflict on the bus.

Housed in a space-saving 16-pin TSSOP package, the PCA9538D is not only practical but also minimizes the PCB footprint. Its I²C-bus speeds can reach up to 400 kHz, making it a fast and efficient solution for expanding I/O capabilities. It also supports hot insertion, which is particularly useful in applications where downtime must be minimized.

The PCA9538D is an ideal solution for a wide range of applications, including servers, personal computers, robotics, industrial control, and any other systems requiring additional I/O expansion. Its robust design and ease of use make it a go-to component for designers looking to enhance their systems without compromising on space or power efficiency.