The T flip-flop is a toggle flip-flop. T stands for toggle. The input T behaves like a control line that specifies a selective toggle. The T flip-flop complements its state when the input T is one. It retains its current state when the input T is zero.
T flip-flop can be obtained by connecting the inputs, J and K of JK flip-flop. There are two way ways by which T flip-flop can be formed.
1. The inputs, J and K of the JK flip-flop can be connected to provide the input, T. The T flip-flop complements its output when T =1 at the clock. The output does not change when T=0 at the clock.
2. The inputs, J and K of the JK flip-flop can be connected to high so that T becomes the clock
Figure: Characteristic table
T flip-flop is not available commercially.