CMCPCI102B

The CMCPCI102B is a 10-channel backplane interface/ termination IC specifically designed for CompactPCI redundant system-slot cards. The CMCPCI102B allows CompactPCI boards to interface to the backplane and provides the versatility to use system cards in any slot (system or peripheral). Per the CompactPCI specification, the CMCPCI102B provides a 10 termination resistor for each channel to terminate the transmission line stub on the board. An integral series switch and associated control signal (SW_EN) permits connection/ disconnection of the channel, so that the device side of the circuit may be isolated from the backplane side.

The CompactPCI standard requires system boards to be hot-swappable. To accommodate this requirement, the CMCPCI102B features a switched 10k resistor connected to the 1V Precharge Supply Voltage. If the precharge enable pin (P_EN) is asserted, then the 10k pull-up resistors are connected to precharge the circuits.

In addition, a system board requirement mandates either a 1.0k pull-up resistor or a 2.7k resistor connected to VIO. CompactPCI slot cards must work in either 3.3V or 5V systems, hence the need for both 2.7k and 1k resistors. If the 3_EN pin is logic high, the 2.7k resistor is used as the pull-up. If the 5_EN pin is logic high, the 1k resistor is used.

The CMCPCI102B integrates all these functions in a low-profile 28-pin TSSOP package.