CD74FCT240
description
The CD74FCT240 is an octal buffer/line driver with 3-state outputs, using a small-geometry Bi CMOS technology. The output stages are a bination of bipolar and CMOS transistors that limit 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 CD74FCT240 is organized as two 4-bit buffers/line drivers with separate active-low output-enable (OE) inputs. When OE is low, the device passes data from the A inputs to the Y outputs. When OE is high, the outputs are in the high-impedance state.
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...
