NXP PCAL6408APWJ 8-bit I/O Expander, I2C, TSSOP-16

The NXP PCAL6408APWJ is an 8-bit I/O expander designed to provide remote I/O expansion for a wide range of microcontroller families via the industry-standard I²C-bus interface. This integrated circuit offers a simple and effective solution for systems requiring additional General-Purpose Input/Output (GPIO) pins while maintaining a minimal interconnection footprint.

A key feature of this device is its built-in level shifting capability, which provides exceptional flexibility in mixed-signal environments. It enables seamless communication between processors and I/O devices operating at different voltage levels, simplifying design where incompatible I/O voltages are present. The device supports a wide dual power rail VDD range from 1.65V to 5.5V, allowing it to interface easily with next-generation low-voltage microcontrollers on the SDA/SCL side while driving peripherals at higher voltages on the port side.

Key Features & Benefits:

• Versatile I/O Expansion: Adds 8 configurable I/O ports via a simple I²C interface, freeing up valuable microcontroller pins.
• Integrated Level Shifting: Eliminates the need for external components when interfacing between different voltage domains (1.65V to 5.5V).
• Robust Design: Features Schmitt-trigger inputs for improved noise immunity and tolerance to slow input transitions.
• Interrupt Handling: Includes an open-drain, active-low interrupt output (INT) with a maskable interrupt-on-change and a read-only register to identify the interrupt source.
• High Drive Capability: Latched outputs can sink/source up to 25mA, sufficient for directly driving LEDs.
• Flexible Configuration: Power-up default sets all channels as inputs with no glitch. Outputs can be configured as push-pull or open-drain on a per-bank basis.
• Input Stability: Input port register values are latched until read, and inputs can be configured with internal