The 74LVC1T45; 74LVCH1T45 are single bit, dual supply transceivers with 3-state outputs that enable bidirectional level translation. They feature two 1-bit input-output ports (A and B), a direction control input (DIR) and dual supply pins (V_CC(A) and V_CC(B)). Both V_CC(A) and V_CC(B) can be supplied at any voltage between 1.2 V and 5.5 V making the device suitable for translating between any of the low voltage nodes (1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V and 5.0 V). Pins A and DIR are referenced to V_CC(A) and pin B is referenced to V_CC(B). A HIGH on DIR allows transmission from A to B and a LOW on DIR allows transmission from B to A.

The devices are fully specified for partial power-down applications using I_OFF. The I_OFF circuitry disables the output, preventing any damaging backflow current through the device when it is powered down. In suspend mode when either V_CC(A) or V_CC(B) are at GND level, both A port and B port are in the high-impedance OFF-state.

Active bus hold circuitry in the 74LVCH1T45 holds unused or floating data inputs at a valid logic level.