| 摘要 |
<p>PURPOSE:To generate a comparison circuit output stable to the fluctuation of a power voltage by supplying a reference voltage to a current decision circuit of a constant current circuit giving a charging current to a capacitor via a voltage generation circuit to a reference voltage. CONSTITUTION:A reference voltage is applied to one input of a comparator circuit 41 and a voltage across a capacitor charged by an output current of a constant current circuit 43 controlled by the reference voltage and generating a constant current is supplied to the other input and the result of comparison between the two inputs. In such a case, a resistor 27 and transistors(TRs) Q28, 29 are added as the voltage generating circuit 44. If the power voltage 26 of the circuit is fluctuated, the fluctuation of both a base voltage of a TR Q13 fed through division resistors and a voltage of a resistor 5 deciding eminently the charge current of a capacitor 7 is identical because they are in common through the TRs Q28, 29, resulting that the fluctuation of the base voltage of the TRs Q12, 13 is identical, an output of a differential amplifier 11 is made stable, and the leading/trailing time of a pulse at an output terminal 25 is immune from the effect of power voltage fluctuation, thereby obtaining stable comparator circuit output.</p> |
