PCA6408A Overview
Description
The PCA6408A is an 8-bit general purpose I/O expander that provides remote I/O expansion for most microcontroller families via the I2C-bus interface. NXP I/O expanders provide a simple solution when additional I/Os are needed while keeping interconnections to a minimum, for example, in battery-powered mobile applications for interfacing to sensors, push buttons, keypad, etc.
Key Features
- that makes these devices extremely flexible in mixed signal environments where communication between incompatible I/O voltages is required
- There are two supply voltages for PCA6408A: VDD(I2C-bus) and VDD(P)
- The bidirectional voltage level translation in the PCA6408A is provided through VDD(I2C-bus)
- VDD(I2C-bus) should be connected to the VDD of the external SCL/SDA lines
- This indicates the VDD level of the I2C-bus to the PCA6408A
- The voltage level on Port P of the PCA6408A is determined by the VDD(P)
- The PCA6408A consists of one 8-bit Configuration (input or output selection), Input, Output, and Polarity Inversion (active HIGH) register
- At power-on, the I/Os are configured as inputs
- However, the system master can enable the I/Os as either inpu
