| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power unit for guaranteeing that a switching element is turned off for each period of a carrier signal Vosc, and for quickly reducing an inductor current when decreasing the inductor current, and to provide a control circuit of the switching power unit. SOLUTION: An output voltage of an error amplifier circuit composed of a transconductance amplifier OTA2 and a capacitor C3 is clamped by a clamping circuit composed of an operational amplifier OP1 and a diode D2, thus guaranteeing that the switching element is turned off for each period of the carrier signal Vosc. A value not more than a clamping voltage becomes an initial value when decreasing an output voltage of the error amplifier circuit, thus decreasing the inductance current quickly when decreasing the inductor current in the switching power unit, and hence quickly decreasing the inductor current. COPYRIGHT: (C)2011,JPO&INPIT |
