3.3-V ABT Octal Registered Transceivers With 3-State Outputs

These octal transceivers are designed specifically for low-voltage (3.3-V) VCC operation, but with the capability to provide a TTL interface to a 5-V system environment.

The 'LVT543 contain two sets of D-type latches for temporary storage of data flowing in either direction. Separate latch-enable (or) and output-enable(or) inputs are provided for each register to permit independent control in either direction of data flow.

The A-to-B enable () input must be low in order to enter data from A or to output data from B. If is low and is low, the A-to-B latches are transparent; a subsequent low-to-high transition of puts the A latches in the storage mode. With and both low, the 3-state B outputs are active and reflect the data present at the output of the A latches. Data flow from B to A is similar but requires using the ,, and inputs.

Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.

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

The SN74LVT543 is available in TI's shrink small-outline package (DB), which provides the same I/O pin count and functionality of standard small-outline packages in less than half the printed-circuit-board area.

The SN54LVT543 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74LVT543 is characterized for operation from -40°C to 85°C.