TI CD74FCT244E

CD74FCT244 and CD74FCT244AT are octal buffers/line drivers with three-state outputs, fabricated using a small-geometry BiCMOS process. The output stage combines bipolar and CMOS transistors to clamp the output HIGH level to approximately two diode drops below VCC. This reduces the output swing to 0 V to 3.7 V, which minimizes power bus ringing (a source of EMI) and reduces VCC bounce and ground bounce — along with their associated effects — during simultaneous output switching. The output configuration also improves switching speed with a sink current capability of 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 a high-impedance state. To ensure the high-impedance state is maintained during power-up or power-down, OE should be connected to VCC through a pull-up resistor; the minimum resistor value is determined by the sink current capability of the driver.

• Low quiescent current BiCMOS process
• Buffered inputs
• Non-inverting outputs
• Input/output isolated from VCC
• Controlled output edge rate
• 64mA output sink current
• Output swing limited to 3.7 V
• SCR latch-up immune BiCMOS process and circuit design