The PCA9571 is a CMOS device that provide 8 bits of General Purpose parallel Output
(GPO) expansion in low voltage processor and handheld battery powered mobile
applications. They operate at 1 MHz I²C-bus speeds on a lightly loaded bus (<100 pF)
while maintaining backward compatibility to Fast-mode (400 kHz) and Standard-mode
The PCA9571 is a streamlined GPO that consists of 8-bit push-pull outputs that offer low
current consumption, small packaging options and a low operating voltage range of 1.1 V
to 3.6 V. The latched outputs are symmetrical 4 mA current drive capability at 3.3 V to
drive various control logic. The PCA9571 output expanders provide a simple solution
when additional outputs are needed while keeping interconnections and floor space to a
minimum, for example, in battery powered mobile applications where PCBs are crowded
for interfacing to sensors, push buttons, etc.
The PCA9571 contains an internal Power-On Reset (POR) and a Software Reset feature
that initializes the device to its default state.