3.3-V ABT Octal Buffers/Drivers With 3-State Outputs

These octal Buffers drivers are designed specifically for low-voltage (3.3-V) VCC operation, with the capability to provide a TTL Interface to a 5-V system environment.
The LVTH241 devices are organized as two 4-bit Line Drivers with separate output-enable (1OE, 2OE) inputs. When 1OE is low or 2OE is high, the devices pass noninverted data from the A inputs to the Y outputs. When 1OE is high or 2OE is low, the outputs are in the high-impedance state.
Active bus-hold circuitry holds unused or undriven inputs at a valid Logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.
When VCC is between 0 and 1.5 V, the devices are in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 1.5 V, OE should be tied to VCC through a pullup resistor and OE should be tied to GND through a pulldown resistor; the minimum value of the resistor is determined by the current-sinking/current-sourcing capability of the driver.
These devices are fully specified for hot-insertion applications using Ioff and power-up 3-state. The Ioff circuitry disables the outputs, preventing damaging current backflow through the devices when they are powered down. The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down, which prevents driver conflict.
By Texas Instruments