NXP 74HC540N 芯片, 74HC CMOS逻辑器件
The is a 8-bit inverting Buffer/Line Driver with 3-state outputs. The device features two output enables OE1 and OE2. A HIGH on OEn causes the outputs to assume a high-impedance OFF-state. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.