| 摘要 |
For load currents greater than a threshold current, the voltage regulator operates in a conventional manner by fully turning on and off one or more switching transistors at a duty cycle necessary to maintain the output voltage a regulated voltage. Upon a load current below a threshold being detected, a controller stops the switching of the transistor(s) and applies a reduced drive signal to the high side transistor so as to apply a constant trickle current to the load. Unnecessary components are shut down to save power. When the output voltage falls below a threshold, the normal switching routine is resumed to recharge the regulator's output capacitor to a certain level, and the regulator once again enters the light load current mode. By not completely shutting down the transistors at light load currents, as in done in a conventional intermittent-operation mode, there is lower power loss by less frequent switching of the transistor(s).
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