The SNx4ACT244 devices are buffer drivers with separate output enable inputs. The active low output enable ensure the outputs are in high impedance when high. 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.
The SNx4ACT244 devices are recommended for 4.5 V to 5.5-V VCC range under normal operating conditions. The inputs are TTL compatible accepting 2-V minimum high at 5-V VCC.
Table 1 lists the functions of the device.