| 摘要 |
<p>PURPOSE:To reduce the frequency variation due to temperature, by cancelling the temperature variation of transistor with the temperature variation of opposite polarity transistor. CONSTITUTION:At the mement when the power supply Vcc is applied, the potential V2 of the time constant circuit consisting of the capacitor 13 and the resistor 14 is zero, and the potential V1 at the junction of the resistors 6, 7 is the voltage division VL of the voltage Vref of the reference voltage 16. Since V1>V2, the output of the voltage comparator 2 is ''1'', turning on the analog switch 4. Thus, transistors TR9 to 11 are turned on, and when V2 is higher than the synthesis voltage VH between the emitter potential of TR9 and the reference voltage Vref, the output of the voltage comparator 2 is ''0'', and switch 4 and TR9 to 11 are opened resulting in V1=VL. On the other hand, when V2<VL, again the state is charging state. Charging and discharge is repeated within the range of VH and VL and the oscillation output is picked up from the terminal 17. In this case, the temperature variation of the emitter potential of TR9 to 11 can be cancelled with TR5 of opposite polarity.</p> |
