Patent ID: 8963522
Filing Date: 2015-02-24
Classification: H02M,Y02B

Abstract:
1. A current-direction detecting circuit configured to detect a direction of current being passed between a source end and a drain end of a switching transistor turning on and off based on a gate signal, the circuit comprising: an amplifier configured to amplify a voltage on the source end to output a first amplified signal and configured to amplify a voltage on the drain end to output a second amplified signal; a first offset compensation capacitor connected to a first output terminal of the amplifier, the first amplified signal being outputted from the first output terminal; a second offset compensation capacitor connected to a second output terminal of the amplifier, the second amplified signal being outputted from the second output terminal; a switch configured to form a first loop circuit comprising the amplifier and the first offset compensation capacitor based on the gate signal when the switching transistor is turned off, configured to form a second loop circuit comprising the amplifier and the second offset compensation capacitor based on the gate signal when the switching transistor is turned off, configured to supply a common reference voltage to the first loop circuit and the second loop circuit in such a manner that a charge is stored in the first offset compensation capacitor and the second offset compensation capacitor, and configured to end the first loop circuit and the second loop circuit based on the gate signal when the switching transistor is turned on; and a monitoring comparator configured to compare a first input signal with a second input signal and configured to output a signal in accordance with a comparison result when the switching transistor is turned on, the first input signal being input through the first offset compensation capacitor, the second input signal being input through the second offset compensation capacitor.