| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve voltage detection accuracy without depending on a method of increasing a clock frequency. <P>SOLUTION: The output voltage detection circuit for a power conversion apparatus comprises: an integration circuit 203 which selects and integrates a voltage to be detected or a result of adding/subtracting the voltage to be detected and a first or second reference voltage; comparators 207, 209; latch circuits 208, 210; and a voltage detection control circuit 206 to which these outputs, a clock signal and a carrier synchronizing signal are input, and which selects an input voltage to the integration circuit 203. The voltage to be detected or a value obtained by adding/subtracting the voltage to be detected and the first reference voltage is selected and integrated in accordance with the output of the latch circuit 208 in a first carrier period, output of the integration circuit 203 at the end of the first carrier period is defined as an initial value in accordance with the output of the latch circuit 210 in a second carrier period, the second reference voltage is integrated, and the first count value of clock signals during the integration period of the first carrier period and the second count value of clock signals during the integration period of the second carrier period are used to measure the voltage to be detected. <P>COPYRIGHT: (C)2009,JPO&INPIT |
