| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching control apparatus which can stably supply a switching power supply voltage.SOLUTION: A voltage slew rate control circuit 6 changes and controls a combined resistance value of a gate resistance connected to a gate of a transistor M1 according to a predetermined noise permission amount. Here, it is assumed that the noise permission amount=Tc×Du×(Vin-Vout)/L×G or the noise permission amount=Tc×(Vout/Vin)×(Vin-Vout)/L×G. When a step-down ratio between an output voltage Vout and an input voltage Vin is large, the noise permission amount can be larger than that of a case where the step-down ratio is small. |
