The HC540 and CD74HCT540 are Inverting Octal Buffers and Line Drivers with Three-State Outputs and the capability to drive 15 LSTTL loads. The HC541 and HCT541 are Non-Inverting Octal Buffers and Line Drivers with Three-State Outputs that can drive 15 LSTTL loads. The Output Enables (OE1\) and (OE2\) control the Three-State Outputs. If either OE1\ or OE2\ is HIGH the outputs will be in the high impedance state. For data output OE1\ and OE2\ both must be LOW.