Patent ID: 7728567
Filing Date: 2010-06-01
Classification: H02M

Abstract:
1. A switching regulator comprising: a driver circuit for receiving a pulse frequency modulation (PFM) signal and responding by turning on a set of first type switching transistors and turning off a set of second type switching transistors; an error amplifier for receiving a first reference voltage and a voltage control loop signal on its input terminals as well as a voltage limit signal on a control terminal, the voltage limit signal setting a maximum output voltage of the error amplifier, the voltage limit signal being a first current control loop signal generated by the driver circuit; a PFM comparator for receiving an output of the error amplifier and a second current control loop signal generated by the driver circuit; a timer circuit for receiving a reset signal generated by the PFM comparator and other current control loop signals generated by the driver circuit, the timer circuit generating the PFM signal based on a steady state mode and at least one of a positive over-current condition and a negative over-current condition; and an LC filter for receiving an output of the driver circuit and generating the voltage control loop signal.