SWITCHED MODE POWER SUPPLY HAVING A STAIRCASE CURRENT LIMIT

摘要

Disclosed is switching power supply that includes a pulse frequency modulation (PFM) mode of operation current feedback control. A reference current source is configured to output a reference current at one of several selectable levels. The level of the reference current may vary during operation of the current feedback control loop.

主权项

1. A circuit comprising:
an output stage; first circuitry configured to generate a first signal representative of changes in a voltage level of an output voltage of the circuit relative to a reference voltage; second circuitry connected to the first circuitry and selectively operable as a function of the first signal, the second circuitry connected to the output stage and configured to generate a control signal to drive the output stage in response to changes in an output current of the output stage relative to a reference current; and a reference circuit configured to generate the reference current, the reference circuit configured to change a level of the reference current from a first level to a second level in response to changes in the output current of the output stage relative to the reference current.