Patent ID: 7394975

Claim:
A drive circuit for a sensored brushless DC motor having a rotating rotor hub, the rotor hub carrying a rotor magnet having magnetic north and south poles, said drive circuit comprising: a first leg comprising: a first p-type MOSFET having a gate, a source and a drain; a first diode, coupled to said first p-type MOSFET, such that a cathode of said first diode is coupled to the drain of said first p-type MOSFET to create a first node; a second leg comprising: a first n-type MOSFET having a gate, a source and a drain; a second diode, coupled to said first n-type MOSFET, such that an anode of said second diode is coupled to the drain of said first n-type MOSFET to create a second node; a first primary winding coupled between said first and second nodes; a third leg comprising: a second p-type MOSFET having a gate, a source and a drain; a third diode, coupled to said second p-type MOSFET, such that a cathode of said third diode is coupled to the drain of said MOSFET to create a third node; a fourth leg comprising: a second n-type MOSFET having a gate, a source and a drain; a forth diode, coupled to said second n-type MOSFET, such that an anode of said fourth diode is coupled to the drain of said second n-type MOSFET to create a fourth node; a second primary winding coupled between said third and fourth nodes, wherein said first MOSFETS provide control over said first primary winding and said second MOSFETS provide control over said second primary winding, so as to provide two-phase control thereof; herein the source of said first p-type MOSFET and said second p-type MOSFET are coupled to the cathode of said second and fourth diodes at a fifth node; and wherein the anode of said first and third diodes are coupled to the source of said first n-type MOSFET and said second n-type MOSFET at a sixth node, and wherein during operation of the drive circuit, said first MOSFETS are substantially simultaneously turned off before said second MOSFETS are turned on, and said second MOSFETS are substantially simultaneously turned off before said first MOSFETS are turned on.