Patent ID: 9673813
Date: 2017-06-06
CPC Classifications: G01R,H02M,H03K

Claim:
1. A power control circuit comprising: first and second power transistors respectively forming a top arm and a bottom arm of a first phase; third and fourth power transistors respectively forming a top arm and a bottom arm of a second phase; first to fourth diodes respectively in inverse-parallel connection with the first to fourth power transistors; first to fourth current measurement circuits that respectively measure currents flowing through the first to fourth power transistors; first to fourth gate drive circuits that output drive voltages for respectively driving the first to fourth power transistors; a control circuit that controls the first to fourth gate drive circuits based on current values respectively measured by the first to fourth current measurement circuits; and a load circuit having a first terminal connected to an output node of the first phase and a second terminal connected to an output node of the second phase, wherein each of the first to fourth power transistors includes a main emitter or main source, and a sense emitter or sense source through which a current corresponding to a current flowing through the main emitter or main source flows, the first to fourth current measurement circuits respectively measure currents flowing through the first to fourth power transistors by using currents flowing through the sense emitter or sense source included in the first to fourth power transistors, and the control circuit obtains a current value flowing through the load circuit by using output values from the first to fourth current measurement circuits, wherein each of the first to fourth current measurement circuits comprises: an operational amplifier having a first input terminal connected to the sense emitter or sense source and a second input terminal connected to the main emitter or main source, and configured to output a signal that controls a voltage of the main emitter or main source and a voltage of the sense emitter or sense source to be substantially the same.