Patent ID: 7800456

Claim:
An oscillator circuit of a power supply controller comprising: a timing input configured to be coupled to a timing element; a synchronization input operably coupled to receive a synchronization signal that has a first state and a second state wherein the synchronization input receives the synchronization signal from external to the oscillator circuit; a first edge detector operably coupled to receive the synchronization signal and set an output of the first edge detector to a first state of the first edge detector responsively to the synchronization signal changing from the first state of the synchronization signal to the second state of the synchronization signal; an oscillator configured to use the timing element to oscillate at a first frequency having a period and to form a clock signal having a first state and a second state during the period, the oscillator configured to restart the clock signal at the first state responsively to the synchronization signal transitioning from the first state of the synchronization signal to the second state of the synchronization signal during an interval where the clock signal is in the second state of the clock signal, and the oscillator configured to not restart the period responsively to the synchronization signal transitioning from the first state of the synchronization signal to the second state of the synchronization signal during an interval where the clock signal is in the first state of the clock signal; and an output circuit operably coupled to receive the clock signal and force the synchronization input to the second state of the synchronization signal responsively to the clock signal transitioning from the second state of the clock signal to the first state of the clock signal.