The controller is FAN2306, which is a constant-on-time controller from Fairchild Semiconductor. The circuit parameters are: V IN = 12V V O = 1.2V F SW = 500kHz L O = 1µH C O = 4x47µF MLCC R T ...

While passive precharge employs a power resistor to create an RC circuit that charges the capacitor asymptotically, active precharge can employ a switching converter with a buck topology that uses ...