| 摘要 |
<p>PURPOSE:To avoid the output pulse width from being affected with the fluctuation of power supply voltage and temperature, by adding a resistor and a transistor (TR) to an input stage of a comparison circuit and forming a reference voltage generating circuit. CONSTITUTION:When a switch 1 is turned off, TRs Q1, Q3, Q6 are turned on and TRs Q2, Q4, Q5 are turned off. In turning on the switch 1 for a short time, the TRQ5 turns on, the TRs Q3, Q6, Q1 turn off and an output voltage Vout goes to a high level. A capacitor C1 is charged through a resistor R3 and a non- inverting input terminal voltage V2 rises. When the voltage reaches an inverting input terminal voltage VH of a reference voltage generating circuit 3 consisting of resistors R1, R2 and R15, and a TRQ7, the output of a comparison circuit 2 is inverted to a high level to turn on the TRQ2 and Q6, and the Vout again goes to a low level.</p> |
