PCA9574/5 - Low Voltage I²C-bus GPIO

PCA9574/75 are I²C-bus 8/16 port GPIO expanders that operate down to 1.1 V with interrupt output with new added features: Bus-hold, programmable pull-ups/pull-downs and maskable I/O ports, interrupt status read ability, software reset and low standby current consumption.

More systems are moving to lower voltages and need the < 1.8 V interface. More complicated system requires the features to prevent the input from floating. These new devices offer a cost down roadmap with smaller packages.

Key Features

I²C compatible, with an interrupt line
Programmable inputs and outputs, with preferable open drain or referenced to 1.8 V supply
4 inputs, 4 outputs at the very minimum
Capability to interrupt the host processor of any changes on the GPIOs.
Bus-hold capability on I/O ports
Programmable pull-ups/pull-downs on I/O ports
Maskable interrupt on I/O port
Interrupt status read ability
Software reset feature
Lower standby current consumption

Key Benefits

With separate supplies to the core and I/O you can easily voltage level translate between 1.1...3.6 V
With maskable input you can prevent interrupts from spurious signals
Low standby current consumption
Programmable bus hold, pull up or pull downs on inputs to prevent floating lines