Octal Buffers And Line Drivers With 3-State Outputs

These octal Buffers and Line Drivers are designed to have the performance of the SN74HCT540 devices and a pinout with inputs and outputs on opposite sides of the package. This arrangement greatly facilitates printed circuit board layout.
The 3-state control Gate is a 2-input NOR. If either output-enable (OE1 or OE2) input is high, all eight outputs are in the high-impedance state. The ?HCT540 devices provide inverted data at the outputs.
To ensure the high-impedance state during power up or power down, OE 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.
By Texas Instruments