CD74FCT540
description
The CD74FCT540 is an octal buffer/driver with 3-state ouputs that is ideal for driving bus lines or buffer memory address registers and uses a small-geometry Bi CMOS technology. The output stage is a bination of bipolar and CMOS transistors that limits the output high level to two diode drops below VCC. This resultant lowering of output swing (0 V to 3.7 V) reduces power-bus ringing [a source of electromagnetic interference (EMI)] and minimizes VCC bounce and ground bounce and their effects during simultaneous output switching. The output configuration also enhances switching speed and is capable of sinking 64 m A.
The 3-state control gate is a two-input AND gate with active-low inputs, so that if either output-enable (OE1 or OE2) input is high, all corresponding outputs are in the high-impedance state. The outputs provide inverted data when they are not in the high-impedance state.
To ensure the high-impedance state during power up or power down, OE should be tied to VCC...
