3.3-V ABT 18-Bit Universal Bus Transceivers With 3-State Outputs

The 'LVT16501 are 18-bit universal bus transceivers designed for low-voltage (3.3-V) VCC operation, but with the capability to provide a TTL interface to a 5-V system environment.

Data flow in each direction is controlled by output-enable (OEAB and ), latch-enable (LEAB and LEBA), and clock (CLKAB and CLKBA) inputs. For A-to-B data flow, the devices operate in the transparent mode when LEAB is high. When LEAB is low, the A data is latched if CLKAB is held at a high or low logic level. If LEAB is low, the A-bus data is stored in the latch/flip-flop on the low-to-high transition of CLKAB. When OEAB is high, the outputs are active. When OEAB is low, the outputs are in the high-impedance state.

Data flow for B to A is similar to that of A to B but uses , LEBA, and CLKBA. The output enables are complementary (OEAB is active high and is active low).

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. OE 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.

The SN74LVT16501 is available in TI's shrink small-outline (DL) and thin shrink small-outline (DGG) packages, which provide twice the input/output (I/O) pin count and functionality of standard small-outline packages in the same printed circuit board area.

The SN54LVT16501 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74LVT16501 is characterized for operation from -40°C to 85°C.