The SN74CBT16212C is a high-speed TTL-compatible FET bus-exchange switch with low ON-state resistance
(ron), allowing for minimal propagation delay. Active Undershoot-Protection Circuitry on the A and B ports of the
SN74CBT16212C provides protection for undershoot up to 2 V by sensing an undershoot event and ensuring
that the switch remains in the proper OFF state.
The SN74CBT16212C operates as a 24-bit bus switch, or as a 12-bit bus-exchange that provides data
exchanging between four signal ports. The select (S0, S1, S2) inputs control the data path of the bus-exchange
switch. When the bus-exchange switch is ON, the A port is connected to the B port, allowing bidirectional data
flow between ports. When the bus-exchange switch is disabled, a high-impedance state exists between the A
and B ports.
This device is fully specified for partial-power-down applications using Ioff. The Ioff feature ensures that
damaging current will not backflow through the device when it is powered down. The device has isolation during
To ensure the high-impedance state during power up or power down, each select input should be tied to GND
through a pulldown resistor; the minimum value of the resistor is determined by the current-sourcing capability
of the driver.