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

description/ordering information
The CD74FCT244 and CD74FCT244AT are octal
buffer/line drivers 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.
These devices are 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 current-sinking capability of the driver.