Document
PCA9512A; PCA9512B
Level shifting hot swappable I2C-bus and SMBus bus buffer
Rev. 6 — 1 March 2013
Product data sheet
1. General description
The PCA9512A/B is a hot swappable I2C-bus and SMBus buffer that allows I/O card insertion into a live backplane without corruption of the data and clock buses and includes two dedicated supply voltage pins to provide level shifting between 3.3 V and 5 V systems while maintaining the best noise margin for each voltage level. Either pin may be powered with supply voltages ranging from 2.7 V to 5.5 V with no constraints on which supply voltage is higher. Control circuitry prevents the backplane from being connected to the card until a stop bit or bus idle occurs on the backplane without bus contention on the card. When the connection is made, the PCA9512A/B provides bidirectional buffering, keeping the backplane and card capacitances isolated.
Both the PCA9512A and PCA9512B use identical silicon (PCN201012007F dated 13 Dec 2010), so the PCA9512.