| 摘要 |
PURPOSE:To obtain a time difference detection circuit having a fast response and small ripple by providing an integration circuit integrating differentially two pulse signals and a sample and holding circuit holding the output of the integration circuit. CONSTITUTION:In closing a switch S1 by an input pulse T1, an output voltage VA1 of an operational amplifier A1 is increased because of the integration of a current I1, and the voltage VA1 is decreased because of the integration of the current I2 when the switch S2 is closed by an input pulse T2. As a result, the output voltage VA1 is increased by a DELTAV, the result of integration is sampled by using a smaple pulse T3 at a sample and holding circuit comprising a switch S3, a capacitor C2 and an operational amplifier A2. In repeating the integration, the DELTAV is made zero. Then the operational amplifier A3 and resistors R12, R20 and R30 form an adder circuit, then an output V0 has a voltage proportional to the difference of pulse width of input pulses T1 and T2 and since the result of integration by the operational amplifier A1 is subject to sample and hold, no ripple is caused at the output voltage VA2 of the operational amplifier A2. |
