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 CD74FCT245 is an octal bus transceiver with 3-state outputs using a small-geometry BiCMOS technology.

The output stages are a combination 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 the 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 CD74FCT245 allows data transmission from the A bus to the B bus or from the B bus to the A bus,

depending upon the logic level at the direction-control (DIR) input. The output-enable (OE) input can be used

to disable the device so that the buses are effectively isolated.

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 CD74FCT245 is characterized for operation from 0°C to 70°C.