DESCRIPTION

· The PCA9557 is a CMOS circuit designed for parallel I/O expansion in SMBus and I2C-bus applications.
· It features an 8-bit input port register, an 8-bit output port register, and an I2C-bus/SMBus interface.
· The device includes a high-impedance open-drain output pin (IO0) and supports low current consumption.
· Configuration, polarity inversion, and reset functionalities are managed via registers and a reset pin.
· Power-on reset initializes the device to default settings without requiring power cycling.

FEATURES

· 8 general-purpose I/O expander with configurable input/output settings.
· Active HIGH polarity inversion and internal power-on reset.
· Noise filters on SCL/SDA inputs and active LOW reset input.
· Supports up to 8 devices on the I2C-bus/SMBus with 3 address pins.
· High-impedance open-drain on IO0, no glitch on power-up, and low standby current.
· Operating voltage range: 2.3 V to 5.5 V with 5 V tolerant I/O.
· Clock frequency: 0 kHz to 400 kHz.
· Robust ESD protection and latch-up testing compliance.
· Available in SO16, TSSOP16, and HVQFN16 packages.

APPLICATIONS

· Suitable for I2C-bus and SMBus-based systems requiring I/O expansion.
· Ideal for applications needing configurable input/output ports with polarity control.
· Used in systems where low power consumption and robust reset functionality are critical.
· Applicable in environments requiring noise filtering and high ESD protection.