SR Latch:

Latches are basic storage components that work with signal levels (rather than signal transitions). Latches are two stable states in a sequential circuit. These are affected by the supplied input voltage and are not affected by the clock pulse.


They are sometimes referred to as preset and clear states. The SR latch serves as the basis for all other types of flip-flops.


SR Latch is a circuit that includes:


  • A pair of cross-coupled NOR gates or a pair of cross-coupled NAND gates.
  • Use S for SET and R for RESET.
  • two outputs Q, Q'.
SR-Latch-TruthTable
SR-Latch-Circuit