| 摘要 |
PURPOSE:To reduce the scale of a circuit by using a single count means so as to generate plural pulse width modulation means (PWM) signals. CONSTITUTION:The single count means 55 driven synchronously with a clock, counting it cyclicly and outputting a count DCT and comparators 56, 57 for plural control systems, that is, a speed error signal DSE and a phase error signal DPE respectively are provided. PWM waves SPW1, SPW2 are obtained by comparison in magnitude of a speed error signal DSE, a phase error signal DPE and a counted value DCT. The counting means applying the count is used in common for the plural control systems to output the resulted counting value thereby allowing the single count means to generate th plural PWM signals. Thus, the scale of circuit is reduced. |
