| 摘要 |
PURPOSE:To obtain a very stable error amplifier with high accuracy by fixing a collector-emitter voltage of a 1st transistor (TR) being a component of a differential amplifier so as to have only to add a few components. CONSTITUTION:Captions R3 and Q7 are respectively a resistor and an NPN TR being components of a level shift circuit (fixed circuit). In the circuit with the constitution as above, a collector-emitter voltage of the TR Q1 at its balancing state is fixed by a current I1, and the resistor R3. That is, even with a power voltage VCC fluctuated, the collector-base voltage of the TR Q1 of the differential input is not fluctuated and not susceptible to the base width modulation effect, then the error amplifier with very high accuracy is obtained.
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