The SN74CB3T3383 is a high-speed TTL-compatible FET bus-exchange switch with low ON-state resistance (r_on), allowing for minimal propagation delay. The device fully supports mixed-mode signal operation on all data I/O ports by providing voltage translation that tracks V_CC. The SN74CB3T3383 supports systems using 5-V TTL, 3.3-V LVTTL, and 2.5-V CMOS switching standards, as well as user-defined switching levels (see Figure 1).

The SN74CB3T3383 is organized as a 10-bit bus switch or as a 5-bit bus-exchange with enable (BE) input. When used as a 5-bit bus-exchange, the device provides data exchanging between four signal ports. When BE is low, the bus-exchange switch is ON, and the select input (BX) controls the data path. When BE is high, the bus-exchange switch is OFF, and a high-impedance state exists between the A and B ports.

This device is fully specified for partial-power-down applications using I_off. The I_off feature ensures that damaging current will not backflow through the device when it is powered down. The device has isolation during power off.

To ensure the high-impedance state during power up or power down, BE should be tied to V_CC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.