Patent ID: 6995531

Claim:
A direct current motor drive circuit for driving a brushless direct current motor, comprising a hall element disposed between predetermined magnetic poles of a coil of the brushless direct current motor; an H-bridge drive circuit including a first comparator which receives an input of a sinusoidal signal outputted from the hall element and outputs a first rectangular wave signal corresponding to the positive voltage of the sinusoidal signal and a second comparator which receives an input of the first rectangular wave signal and outputs a second rectangular wave signal corresponding to the negative voltage of the sinusoidal signal; a dead time circuit which carries out rectangular wave signal processing for turning the first rectangular signal and the second rectangular signal on at timings in which their ON voltage periods are different; and an H-bridge circuit which receives inputs of the first rectangular wave signal and the second rectangular wave signal subjected to signal processing in the dead time circuit, wherein the H-bridge circuit includes a first series circuit in which a second switching element connected to a positive power supply voltage and a first field effect transistor (referred to as FET) connected to the ground are connected in series via a first node, a second series circuit in which a first switching element connected to the positive power supply voltage and a second FET connected to the ground are connected in series via a second node, and a coil of the direct current motor connected to the first node and the second node.