BiCMOS Technology With Low Quiescent

Power

Buffered Inputs

Noninverted Outputs

Input/Output Isolation From VCC

Controlled Output Edge Rates

64-mA Output Sink Current

Output Voltage Swing Limited to 3.7 V

SCR Latch-Up-Resistant BiCMOS Process

and Circuit Design

Package Options Include Plastic

Small-Outline (M) and Shrink Small-Outline

(SM) Packages and Standard Plastic (E) DIP

description

The CD74FCT541 is an octal buffer/driver with 3-state outputs that is ideal for driving bus lines or buffer memory

address registers and uses a small-geometry BiCMOS technology. The output stage is a combination 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 mA.

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 noninverted

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 through a pullup

resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

The CD74FCT541 is characterized for operation from 0°C to 70°C.