Cyclical dc voltage converter for suppressing voltage spikes and oscillations

Abstract

A DC voltage converter is provided that cyclically converts an input-side supply voltage into an output voltage. The converter includes an inductive storage element connected between a terminal for the supply voltage and, in a manner such that it is coupled via a first switch, a reference potential terminal. The capacitively buffered output voltage terminal is connected, via a second switch, between the inductive storage element and the first switch. Provision is furthermore made of a third switch, which is intended to selectively short the inductive storage element that is connected in parallel and is controlled by a control circuit. The control circuit is controlled, on the input side, by a control voltage that is tapped off at the second terminal of the inductive storage element.

1 . A DC voltage converter, comprising:
 an inductance coupled between a supply potential and a feedback node;   a capacitance coupled between an output terminal and a reference potential;   a first switch coupled between the feedback node and the reference potential;   a second switch coupled between the feedback node and the output terminal;   a third switch coupled in parallel with the inductance; and   a control circuit configured to generate a control signal operable to selectively activate the third switch based on a voltage condition at the feedback node.   
   
   
       2 . The DC converter of  claim 1 , further comprising a regulating circuit configured to generate switching signals for the first and second switches, respectively, wherein the switching signals are configured to charge the inductance in a first phase, discharge the inductance and charge the capacitance in a second phase, and deactivate both the first and second switches in a third phase. 
   
   
       3 . The DC converter of  claim 2 , wherein the control circuit is configured to identify an undershoot condition or an overshoot condition at the feedback node during the third phase and close the third switch via the control signal in response thereto.