System and method for input voltage regulation of switch mode supplies implementing burst mode operation

摘要

Switching regulator methods and systems are provided for supplying output current at a regulated voltage level to a load. Upon determining that the output current is not below a predetermined current threshold, the regulator is operated in a continuous mode. The input voltage is monitored. If the input voltage is not below a first input threshold level, the system remains in continuous mode. Otherwise, the system enters a burst mode in which the switch mode power supply is turned OFF, thereby reducing transistor gate charge losses.

主权项

1. A switching regulator that supplies output current at a regulated voltage level to a load, the switching regulator being operable in a burst mode, the switching regulator comprising:
an input node; an output node coupled to the load; a switch mode power supply coupled to the load; and a control circuit coupled between the input node and the switch mode power supply, wherein the control circuit is configured to determine when to enter burst mode, in which switching elements of the switch mode power supply provide output current to the load on an intermittent aperiodic basis, based on a voltage at the input node that is below a predetermined threshold level and at least one of (i) a current at the input node or (ii) the output current being below a predetermined current threshold.