PCA9574
description
The PCA9574 is a CMOS device that provides 8 bits of General Purpose parallel Input/Output (GPIO) expansion in low voltage processor and handheld battery powered mobile applications and was developed to enhance the NXP family of I2C-bus I/O expanders. The improvements include lower supply current, lower operating voltage of 1.1 V to 3.6 V, dual and separate supply rails to allow voltage level translation anywhere between 1.1 V and 3.6 V, 400 k Hz clock frequency, and smaller packaging. Any of the eight I/O ports can be configured as an input or output independent of each other and default on start-up to inputs. 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 and clamshell devices for interfacing to sensors, push buttons, keypad, etc. In addition to providing a flexible set of GPIOs, it simplifies interconnection of a processor running at one voltage level...
