| 摘要 |
<P>PROBLEM TO BE SOLVED: To independently optimize the control operation time in PWM control processing and the frequency of carrier signals for synchronization for synchronizing with a PWM carrier signal, in this PWM control processing. <P>SOLUTION: This PWM controller generates a carrier synchronizing signal S2, with the rise of a carrier signal S1 as the trigger for synchronization generated in a carrier generating circuit 11, and counts the number of pulses of this carrier-synchronizing signal S2. This takes the logical sum of a PWM control action permitting signal S4, which starts with a given delay time, when this number of pulses amounts to a specified number, and the carrier-synchronizing signal S2, and starts a PWM control circuit 16 with the time of the rise of the number of pulses of the carrier-synchronizing signal S2 is a specified value, and when the rise the carrier-synchronizing signal S2 is set as the trigger. Since this can tunes the start timing of the PWM control circuit 16 by changing the specified value of the carrier synchronizing signal S2, the frequency of the carrier-synchronizing signal S2 can be set, regardless of the control operation time of the PWM control circuit 16. <P>COPYRIGHT: (C)2004,JPO |
