General description
The PCA9522 is a monolithic bipolar integrated circuit for bus buffering in applications including I2C-bus, SMBus, etc. It includes hot insertion logic for detecting stop and idle conditions, making it ideal for live insertion into backplanes. The buffer extends the bus load limit by buffering both the SCL and SDA lines. The PCA9522 is a drop-in replacement for the IES5502, with only the maximum bus voltage reduced from 15 V to 10 V.

Features and benefits
■ Dual, bidirectional unity gain isolating buffer
■ Hot insertion logic prevents data and clock bus corruption for live backplane applications
■ Pre-charge minimizes data corruption on live insertion
■ Supports I2C-bus (Standard-mode and Fast-mode), SMBus (standard and high power modes) and PMBus
■ Open-collector ready output (RDY)
■ Fast switching times allow operation in excess of 1 MHz
■ Enable (EN) allows bus segments to be disconnected
■ Low current standby mode when not enabled
■ High-impedance ports when IC unpowered
■ 6 mA (static) pull-down capability
■ Low noise susceptibility
■ Supports the connection of several buffers in series
■ Level shift bus voltages from 1.8 V to 10 V