MOTOR DRIVE DEVICE, MOTOR DRIVE CIRCUIT, MOTOR DRIVE IC, COOLING DEVICE EMPLOYING THE SAME, AND ELECTRONIC APPARATUS

摘要

PROBLEM TO BE SOLVED: To improve linearity of a rotation speed with respect to control input.;SOLUTION: An analog control voltage V_TH indicating the rotation speed is inputted to a TH terminal. In an OSC terminal, a capacitor C21 and a discharge resistor R22 are connected in parallel between an OSC and the ground in a first platform. A charge resistor R21 and a first switch 252 are provided in series between a reference voltage line 254 in which a voltage is stabilized, and the OSC terminal. When an oscillator voltage V_OSC that is generated in the OSC terminal reaches an upper threshold value V_H, a switch circuit 250 turns off the first switch 252 and when the oscillator voltage V_OSC falls down to a lower threshold V_L, the switch circuit turns on the first switch 252. The oscillator voltage V_OSC is compared with the voltage V_TH of the TH terminal and a pulse-modulated control pulse S3 is generated.;SELECTED DRAWING: Figure 4;COPYRIGHT: (C)2017,JPO&INPIT