| 摘要 |
PURPOSE:To decrease the rise of an output current droop start point based on the change in an input voltage, by protecting overcurrent with a signal obtained through the addition of an input voltage detection signal to a current detection signal. CONSTITUTION:Resistors R1, R2, a diode D2, and capacitor C2 constitute a current detection section A, and resistors R3, R4 constitute an input voltage addition section B. Taking a voltage produced across the resistor R2 with a reactor current iL as a Vs, a voltage V1 applied to one input terminal of an error amplifier 1 is represented as the addition with a voltage across the resistor R4 of the voltage Vs. When an input voltage Vin is low, the detection voltage Vs based on the reactor current is large, and when the voltage Vin is high, the voltage Vs is small, then the change in the drooping point of the output current can be decreased regardless of the change in the input voltage. |
