PCA9511

   The PCA9510 and PCA9511 are hot swappable I²C and SMBus buffers that allows I/O card insertion into a live backplane without corrupting the data and clock buses. Control circuitry prevents the backplane from being connected to the card until a stop command or bus idle occurs on the backplane without bus contention on the card. When the connection of PCA9511 is made, the PCA9510 and PCA9511 provides bi-directional buffering, keeping the backplane and card capacitances isolated.

   The PCA9511 rise time accelerator circuitry allows the use of weaker DC pull-up currents while still meeting rise time requirements, while the PCA9510 has no rise time accelerator circuitry to prevent interference when there are multiple devices in the same system. The PCA9510 and PCA9511 incorporate a digital ENABLE input pin, which enables the device when asserted HIGH and forces the device into a low current mode when asserted LOW,
and an open-drain READY output pin, which indicates that the backplane and card sides are connected together (HIGH) or not (LOW).