Patent ID: 7019497

Claim:
A method for synchronizing a non-constant frequency switching regulator that generates a regulated voltage output at an output node, the method comprising: controlling the duty cycle of the switching regulator with control circuitry coupled to the output node and adapted to receive one or more variables, the control circuitry generating a pulse that is proportional or inversely proportional or approximately inversely proportional to one of the one or more variables; providing as one of the one or more variables a signal corresponding to a voltage at an input node of the switching regulator or a signal corresponding to a voltage at the output node of the switching regulator; and providing the control circuitry with an output of a phase locked loop having an input for receiving a clock signal and an output at which a signal is generated to control a parameter of the switching regulator, the phase locked loop adjusting the switching frequency of the switching regulator through control of the parameter.