| 摘要 |
PROBLEM TO BE SOLVED: To suppress power consumption during a standby operation.SOLUTION: A feedback amplifier IC 400 is connected with an input side of a photocoupler 204. As an output voltage Vof a DC-DC converter 200 is lower, an error current Iis generated more increasingly. A primary side controller 202 has a feedback (FB) terminal, and as a voltage Vof a FB terminal is higher, a switching transistor M1 is switched at a higher duty ratio. A non-inversion type feedback circuit 208 is connected with an output side and the FB terminal of a photocoupler 204. As a feedback current Irunning through the output side of the photocoupler 204 increases more, the voltage Vof the FB terminal becomes higher.SELECTED DRAWING: Figure 2 |
