| 摘要 |
A motor drive circuit which can be suitably made into a small IC, has a reduced number of outer components and a small size, and is capable of stably rotating a motor. When a rotor (101) is rotated by three-phase drive signals U, V, W generated according to a CLK signal from a VCO (7), the induced voltage in the three-phase coil (102) is monitored, and the phase shift from the electrical phase of the rotor phase is detected. A charge pump circuit (5) is driven with an up signal f_up which is active for the time corresponding the phase delay when the rotor phase is lagged behind the electrical phase or with a down signal f_down which is active for the time corresponding to the phase lead when the rotor phase is ahead of the electrical phase. This motor drive circuit (1) instantaneously, dynamically, and directly varies the voltage at the VCO control terminal (T_cp) according to the detected phase shift information without using a smoothing filter. ® KIPO & WIPO 2007 |
