These device are positive edge triggered flip-flops. The difference between HD74HCT374 and HD74HCT534 is only that the former is a true outputs and the latter is a false outputs. Data at the D inputs, meeting the setup and hold time requirements, are transferred to the Q outputs on positive going transitions of the clock (CK) input. When a high logic level is applied to the output control (OC) input, all outputs go to a high impedance state, regardless of what signals are present at the other inputs and the state of the storage elements.


  • LSTTL Output Logic Level Compatibility as well as CMOS Output Compatibility
  • High-Speed Operation: tpd (Clock to Q) = 15 ns typ (CL = 50 pF)
  • High Output Current: Fanout of 15 LSTTL Loads
  • Wide Operating Voltage: VCC = 4.5 to 5.5 V
  • Low Input Current: 1 µA max
  • Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C)




Design & Development