| 摘要 |
<p>A phase shifting circuit for shifting a phase of an input pulse signal comprises a first circuit for delaying the input pulse signal so as to produce a first pulse signal having a first pulse width, a second circuit for delaying the first pulse signal so as to produce a second pulse signal having a second pulse width, a smoothing circuit for smoothing the second pulse signal, and a comparing circuit for comparing an output signal level of the smoothing circuit with a predetermined reference level so as to produce a control signal dependent on a difference between the two compared levels. The control signal is supplied to the first and second circuits to control delay times thereof so that the first and second pulse widths respectively become constant. The second delay circuit produces the second pulse signal as an output pulse signal of the phase shifting circuit having a period essentially identical to that of the input pulse signal but having a phase which is shifted by a predetermined quantity with respect to the phase of the input pulse signal, where the predetermined quantity is substantially constant regardless of a period of the input pulse signal.</p> |
