NXP PCA9535D 16-bit I²C-bus and SMBus I/O Expander

The PCA9535D is a robust and versatile 16-bit I/O expander from NXP Semiconductors designed to provide remote I/O expansion for most microcontroller families via the I²C-bus and SMBus. This highly integrated device is an ideal solution for applications where additional I/Os are needed, and it is particularly suited for use in servers, gaming machines, industrial equipment, and more.

The PCA9535D operates with a supply voltage range of 2.3V to 5.5V, allowing it to support both 3.3V and 5V logic levels, thus providing great flexibility in interfacing with different microcontrollers. Additionally, it features an active LOW interrupt output which can be connected to the interrupt logic of the host microcontroller to indicate that an input state has changed, enhancing system responsiveness and efficiency.

Each of the 16 I/Os can be independently configured as an input or output, enabling customizable applications. The device ensures robust operation with built-in power-on reset and low standby current, making it suitable for low power applications. Furthermore, the PCA9535D offers a polarity inversion register that allows users to invert the polarity of the input port data if necessary.

The PCA9535D is housed in a space-saving 24-pin TSSOP package, making it a compact solution for space-constrained applications. Its I²C-bus address is set by 3 hardware address pins, allowing up to eight devices to share the same bus. This feature simplifies design and reduces the complexity of the communication protocol, as multiple devices can be addressed individually over a single bus.

For ease of integration, the PCA9535D is fully compliant with the I²C-bus Fast-mode Plus specification, supporting data transfer rates of up to 1 Mbit/s, and it is also compatible with SMBus standards. This ensures that the device can be easily integrated into existing systems with minimal software overhead and without the need for complex interfacing.

In conclusion, the PCA9535D from NXP is a highly reliable I/O expander that offers enhanced functionality, ease of use, and integration flexibility, making it a top choice for designers looking to expand the I/O capabilities of their microcontroller-based systems.