Patent ID: 8710820
Filing Date: 2014-04-29
Classification: H02J,H02M,Y02B

Abstract:
1. A boost converter power supply, comprising: a boost stage configured to convert an input signal having a first voltage level into an intermediate signal having a second voltage level, the second voltage level higher than the first voltage level; an operating capacitor electrically coupled to an output of the boost stage; a hold-up capacitor electrically coupled to the output of the boost stage under a first condition and electrically coupled to an input of the boost stage under a second condition; a detection circuit configured to provide a failure signal upon loss of the input signal; a slow transient response circuit coupled to the input signal; a fast transient response circuit coupled to the input signal; a switching circuit that, responsive to receipt of the failure signal from the detection circuit, isolates the slow transient response circuit from the input signal and couples the fast transient response circuit to the input signal; and a controllable switching circuit having a first controllable switch element and a second controllable switch element, the first and second controllable switch elements each having a first node directly connected to the holdup capacitor, the first controllable switch element having a second node directly connected to the output of the boost stage, the second controllable switch element having a second node electrically coupled to the input of the boost stage, the controllable switching circuit responsive to the failure signal and operable to disconnect, via the second controllable switch element, the hold-up capacitor from the input of the boost stage and connect, via the first controllable switch element, the hold-up capacitor to the output of the boost stage in parallel with the operating capacitor in the first condition when the failure signal has a first state, the controllable switching circuit further operable to disconnect, via the first controllable switch element, the hold-up capacitor from the output of the boost stage and connect, via the second controllable switch element, the hold-up capacitor to the input of the boost stage in the second condition when the failure signal has a second state.