The PCA9510A is a hot swappable I2C-bus and SMBus buffer that allows I/O cardinsertion into a live backplane without corrupting the data and clock buses. Controlcircuitry prevents the backplane from being connected to the card until a stop command orbus idle occurs on the backplane without bus contention on the card. When theconnection is made, the PCA9510A provides bidirectional buffering, keeping thebackplane and card capacitances isolated.