| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an overcurrent protection technology which prevents malfunction of overcurrent protection under impact of noise generated suddenly while protecting a switching element surely from overcurrent in a motor control circuit. <P>SOLUTION: The motor control circuit includes a drive signal generation circuit (22) which generates and outputs a gate signal for turning the switching elements (31u-31w, 31x-31z) of an inverter circuit (30) on/off based on the positional information of the rotor and a PWM command, and an overcurrent detection circuit (26) which detects a current flowing through the inverter circuit. The overcurrent detection circuit (26) removes the high frequency components of a signal according to the current flowing through the inverter circuit, and compares that signal with a signal indicating a predetermined current value thus detecting existence of overcurrent. When an overcurrent is detected, the drive signal generation circuit (22) generates a gate signal so that each switching element is turned off. Furthermore, overcurrent detection result is notified to an external CPU (50) through an output terminal (OVP). <P>COPYRIGHT: (C)2010,JPO&INPIT |
