JPS6424506A - Pulse delay circuit - Google Patents

Abstract

PURPOSE:To obtain a simple circuit which has high accuracy of pulse delay time by correcting delay time according to the difference between the pulse delay time and desired preset delay time. CONSTITUTION:A delay pulse generation part 1 outputs delay pulses which are delayed by specific delay time and has constant cycles by comparing the voltage of a saw-tooth wave with a reference voltage by a comparator. The output delay pulses of the delay pulse generation part 1 becomes the output signal of a pulse delay circuit and are supplied to a delay time detection part. The delay time detection part 2 detects the delay time according to the duty cycle of the supplied delay pulses and a delay time error correction part detects the difference between the delay time of the delay pulses and preset delay time by using a detection signal from the delay time detection part and a signal corresponding to the preset delay time and varies the time constant or reference voltage of the charging and discharging capacitor in the delay pulse generation part to correct the delay time into a specific value. Consequently, a pulse delay circuit with good delay accuracy is obtained by using a simple circuit.