PCAL6408AEX1Z

I/o Expanders Overview

The PCAL6408AEX1Z is an 8-bit general-purpose I/O expander manufactured by NXP Semiconductors. It provides remote I/O expansion via the I2C-bus interface and supports bidirectional voltage-level translation between the controller side (VDD(I2C-bus)) and port P (VDD(P)). The device operates within a supply voltage range of 1.65 V to 5.5 V, supporting combinations such as 1.8 V SCL/SDA with 1.8 V to 5 V Port P. It features a 400 kHz fast-mode I2C-bus, open-drain active LOW interrupt output, and active LOW reset input. The component is housed in an X2QFN16 package.

I/o Expanders Feature Summary

• Bidirectional voltage-level translation capability between varying I2C bus voltages and port supply levels
• Agile I/O features including programmable drive strength, input latching, and configurable pullup/pulldown resistors
• Interrupt status register identifies the source of interrupts while masking prevents spurious signals at power-up

I/o Expanders Applications

• Battery-powered mobile applications for interfacing to sensors and push buttons
• Interfacing processors running at one voltage level to peripherals operating at different voltage levels
• Remote I/O expansion for microcontroller families requiring minimal interconnections

I/o Expanders Procurement Notes

Verify the specific ordering part number against the manufacturer's current datasheet revision to ensure compatibility with the required package type. Confirm that the X2QFN16 package meets the design constraints, as previous packages like XFBGA16 have been discontinued. Ensure all electrical parameters align with the system requirements before finalizing procurement orders.

I/o Expanders Selection Notes

Select this component when mixed-signal environments require communication between incompatible I/O voltages. The PCAL6408AEX1Z is suitable for designs needing software backward compatibility with PCA6408A but requiring Agile I/O enhancements. Consider the dual power rail configuration to optimize standby current consumption and noise immunity for sensitive microcontroller interfaces.

I/o Expanders Part Context

The PCAL6408AEX1Z belongs to the PCAL6408A series of low-voltage translating I/O expanders. It serves as a pin-to-pin replacement for the PCA6408A, offering enhanced features such as Agile I/O capabilities. The EX1 suffix specifically denotes the X2QFN16 land grid array package, which is recommended for new designs replacing the discontinued XFBGA16 variant.

I/o Expanders Replacement Considerations

The PCAL6408AEX1Z is a direct pin-to-pin drop-in replacement for the PCA6408A. Designers should note that the PCAL6408A powers up with all I/O interrupts masked by default, unlike some predecessors, to prevent spurious interrupts during board bring-up.