Rohm Co., Ltd.

Toshikazu Satake

Hiroyuki Ishii

Hiroaki Hayashi

A driving device capable of driving a motor more efficiently is provided. A zero-crossing detection comparatorcompares a pair of Hall signals H+ and H&#x2212; having reverse phases and representing a rotor position of a fan motor, and generates a level-shifted zero-crossing detection signal Sat each zero-crossing timing when the Hall signals cross each other. A control circuitreceives the zero-crossing detection signal S, switches a driving phase at each zero-crossing timing to rotationally drive the motor, and regeneratively controls the motor during a duration from a first time point ahead of each zero-crossing timing by a first time width &#x3c4;to a second time point behind each zero-crossing timing by a second time width &#x3c4;shorter than the first time width &#x3c4;

Motor driving circuit and method, and cooling device and electronic apparatus using the same

A drive signal generation circuit generates drive signals that control ON and OFF states of transistors of a H-bridge circuit, in accordance with a target value of torque. A driver circuit alternatively turns ON and OFF high side transistors, and low side transistors of the H-bridge circuit, based on the drive signals outputted from the drive signal generation circuit. The driver circuit immediately turns OFF the high side transistors, when an instruction is issued to stop a motor, and after a predetermined delay time &#x3c4;d has elapsed, turns OFF the low side transistors.

Growing community of inventors

Kyoto, Japan

Toshikazu Satake