CD74FCT574

The CD74FCT574 is an octal, D-type, edge-triggered flip-flop that features noninverted, 3-state outputs, designed specifically for driving highly capacitive or relatively low-impedance loads. The devices are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.

CD74FCT574 uses a small-geometry BiCMOS technology. The CD74FCT574 output stage is a combination of bipolar and CMOS transistors that limits the output high level to two diode drops below V_CC. This resultant lowering of output swing (0 V to 3.7 V) reduces power-bus ringing [a source of electromagnetic interference (EMI)] and minimizes V_CC bounce and ground bounce and their effects during simultaneous output switching. The output configuration also enhances switching speed and is capable of sinking 48 mA.

The CD74FCT574 eight flip-flops enter data into their registers on the low-to-high transition of the clock (CLK). On the positive transition of the clock (CLK) input, the Q outputs are set to the logic levels set up at the data (D) inputs.

The CD74FCT574 output-enable (OE) input controls the 3-state outputs and is independent of the register operation. OE can be used to place the eight outputs in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. Old data can be retained or new data can be entered while the outputs are in the high-impedance state.

The CD74FCT574 is characterized for operation from 0°C to 70°C.