NXP PCAL6416A I/O Expander, 16-bit, I2C, HWQFN-24

The NXP PCAL6416A is a versatile 16-bit input/output (I/O) expander designed for remote I/O expansion via the I²C bus, offering a simple, space-saving solution for microcontroller-based systems requiring additional input/output pins. It acts as a crucial bridge, facilitating seamless communication between processors and peripheral devices operating at different voltage levels, thanks to its integrated level-shifting capability. Its dual power rail supports a wide VDD range from 1.65V to 5.5V, enabling connection to next-generation low-voltage microcontrollers on the interface side while driving peripherals at higher voltages on the port side.

This device significantly enhances system design flexibility by minimising interconnections and simplifying mixed-signal environments. Key operational features include low standby current consumption for power efficiency and Schmitt-trigger inputs that allow for slow signal transitions while providing superior immunity to switching noise. For system management, it includes an open-drain, active-low interrupt output (INT) and an internal power-on reset function. On power-up, all 16 channels are safely configured as inputs with no glitch, ensuring stable initialisation.

The outputs are latched and offer a drive capability of up to 25mA per pin, making them suitable for directly driving LEDs or other small loads. The output stages are configurable on a per-bank basis as either push-pull or open-drain. Robustness is assured with excellent latch-up performance exceeding 100mA per JESD 78, Class II standards. For reliable input handling, the device features programmable pull-up/pull-down resistors (100kΩ) on each pin and a mask function to prevent interrupt generation on specific input changes. Interrupt source identification is streamlined via a dedicated read-only register.

Key Features & Specifications

• I/O Expansion: Provides 16 additional configurable GPIO pins.