The Fairchild Switch FSTU6800 provides 10-bits of highspeed CMOS TTL-compatible bus switching. The low on resistance of the switch allows inputs to be connected to outputs without adding propagation delay or generating additional ground bounce noise. Both the A Ports and the B Ports are "undershoot hardened" with UHC protection to support an extended input range to 2.0V below ground. Fairchild's integrated Undershoot Hardened Circuit, UHC senses undershoot at the I/Os, and responds by preventing voltage differentials from developing and turning on the switch. The device also precharges the B Port to a selectable bias voltage (BiasV) to minimize live insertion noise.