Patent ID: 7902884
Filing Date: 2011-03-08
Classification: H02M

Abstract:
1. An H-bridge circuit having a power supply terminal, a ground terminal, a first node, and a second node, the H-bridge circuit comprising: a first upper-arm MOSFET for conducting current between the power supply terminal and the first node; a first lower-arm MOSFET for conducting current between the first node and the ground terminal, the first lower-arm MOSFET having a source connected to the ground terminal, a drain connected to the first node, and a first parasitic diode; a second upper-arm MOSFET for conducting current between the power supply terminal and the second node; a second lower-arm MOSFET for conducting current between the second node and the ground terminal, the second lower-arm MOSFET having a source connected to the ground terminal, a drain connected to the second node, and a second parasitic diode; a coil load connected between the first node and the second node; a first current supplying element connected in parallel with the first parasitic diode and conductively interconnecting the source and drain of the first lower-arm MOSFET when the drain of the first lower-arm MOSFET is negatively biased, thereby supplying current to the drain of the first lower-arm MOSFET; and a second current supplying element connected in parallel with the second parasitic diode and conductively interconnecting the source and drain of the second lower-arm MOSFET when the drain of the second lower-arm MOSFET is negatively biased, thereby supplying current to the drain of the second lower-arm MOSFET.