| 摘要 |
A phase comparator which comprises a differential amplifier; and a first and a second active load circuit each comprising a current mirror circuit and from which is derived an output signal which is reversed in phase with respect to the output of the differential amplifier. The outputs of the respective active load circuits are superimposed upon each other through other current mirror circuits, and an output resulting from the superimposition is alternately provided based on rectangular waveform signals which are reversed in phase with respect to each other. By smoothing the output, a DC output corresponding to the phase shift of input signal from the rectangular waveform signals is produced. The phase comparator comprises a combination of transistors and diodes which are cascode-connected to each other, and thus is operable with a predetermined voltage as low a 1 V or less.
|
