Patent ID: 7049772

Claim:
A motor drive circuit which has a first source-side transistor and a first sink-side transistor connected in series; a second source-side transistor and a second sink-side transistor connected in series; and a control circuit supplying the first source-side transistor, the first sink-side transistor, the second source-side transistor, and the second sink-side transistor with control signals for supplying a current in one direction or the opposite direction to a coil connected between a connection point of the first source-side transistor and the first sink-side transistor and a connection point of the second source-side transistor and the second sink-side transistor based on a plurality of input signals that complementarily change at a predetermined frequency, wherein the control circuit, during each time period between timings of complementary switching of the plurality of input signals, outputs control signals for holding two to-operate transistors turned off for a predetermined time, which transistors are either the first source-side transistor and the second sink-side transistor or the second source-side transistor and the first sink-side transistor, and then, while holding one transistor of the two to-operate transistors turned on all the time, turning on and off the other transistor at timings when one of the input signals changes at a predetermined frequency, which transistors are either the first source-side transistor and the second sink-side transistor or the second source-side transistor and the first sink-side transistor.