| 摘要 |
A phase detector produces a pulsed tri-state output signal representing a phase difference between first and second input signals. The pulse width of the output signal indicates the magnitude of the phase difference while the sign of the output signal pulses indicates whether the first input signal leads or lags the second input signal. The first and second input signals drive D and clock inputs, respectively, of a type D flip-flop, and also drive separate inputs of an XOR gate. An output of the flip-flop provides a signal input to a tristate buffer while an output of the XOR gate drives a tri-state control input of the tristate buffer. The tristate buffer produces the phase detector output signal.
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