T flip-flop
T flip-flop: with T=1 it toggles on every rising clock edge; with T=0 it holds.
Characteristic table (on the CLK 0→1 edge)
| T | Q⁺ |
|---|---|
| 0 | Q (hold) |
| 1 | Q̄ (toggle) |
Pins
T and CLK on the left; Q and its complement Q̅ on the right.
How to use it
Frequency halving; connect each stage's Q to the next stage's CLK for a ripple counter.
Usage example
T and the clock go on the left. With T = 1, Q flips on every tick at half the clock's frequency — the building block of counters.
Common mistakes
A floating T counts as 0, so the flip-flop never changes.