| 摘要 |
Techniques for near zero light-load supply current in switching power supply are described. In one embodiment, a switching power supply comprises sub-circuits, a capacitor/inverter circuit, and a standby control circuit. The sub-circuits comprise a feedback resistor that supplies a fraction of an output voltage of the power supply, an integrator that provides an integrator output, a comparator that provides a pulse width modulated signal, a switching element that receives the pulse width modulated signal and modulates current such that the power supply provides a regulated voltage, and a monitoring circuit that provides a logic low signal when the pulse width modulated signal is absent over a period of time. The standby control circuit disables the sub-circuits when the logical low signal is detected permitting the switching power supply to operate at a minimum current, an re-enables the sub-circuits when an out of regulation signal from the capacitor/inverter circuit is detected.
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