Method of forming a semiconductor device
AssigneeSemiconductor Components Industries, LLC
InventorsMartin Podzemny, Vaclav Peroutka
Life of this patent
Estimating the term…
Abstract
In one embodiment, a controller for a power supply may be configured to operate as a quasi-resonant controller while operating in a discontinuous current mode and to operate as one of a pulse width or pulse frequency modulation controller while operating in a continuous current mode. The controller may have an embodiment that varies a frequency of the switching drive signal around a center frequency while operating in the continuous current mode, and varies a value of a current sense signal but not vary the frequency of the switching drive signal around a center frequency while operating in the discontinuous current mode.
Claims17
A controller for a power supply comprising:
- a control circuit configured to select the controller for operating in a continuous current mode or a discontinuous current mode and to switch therebetween;
- a first jitter circuit configured to vary a frequency of a clock signal around a center frequency of the clock signal in response to operating in the continuous current mode;
- and
- a current sense circuit including a second jitter circuit configured to form a DCM jitter signal, the current sense circuit configured to vary a current sense signal by the DCM jitter signal, in response to operating in the discontinuous current mode, wherein the current sense circuit does not substantially vary the current sense signal by the DCM jitter signal in response to operating in the continuous current mode.
A method of forming a controller for a power supply comprising:
- configuring the controller to form a switching drive signal having cycles to control a primary current through a transformer to regulate an output voltage to a desired value, the controller receiving a current sense signal that is representative of the primary current;
- configuring the controller to operate in either a discontinuous current mode or to operate in a continuous current mode, and to switch therebetween wherein the controller varies a frequency of the switching drive signal around a center frequency while operating in the continuous current mode and wherein the controller forms a compensated current sense signal that varies a value of the compensated current sense signal around a value of the current sense signal while operating in the discontinuous current mode;
- and
- configuring the controller to transition from the discontinuous current mode to the continuous current mode in response to a discontinuous current mode cycle in which the controller does not does not vary the value of the compensated current sense signal;
- and
- configuring the controller to form a first cycle after transitioning from the discontinuous current mode to the continuous current mode to vary the frequency in a direction that is opposite to a direction in which the controller varied the compensated current sense signal during an immediately preceding discontinuous current mode cycle.
A method of forming a controller for a power supply comprising:
- configuring the controller to form a switching drive signal having cycles to control a primary current through a transformer to regulate an output voltage to a desired value, the controller receiving a current sense signal that is representative of the primary current;
- configuring the controller to operate in either a discontinuous current mode or to operate in a continuous current mode, and to switch therebetween wherein the controller varies a frequency of the switching drive signal around a center frequency while operating in the continuous current mode and wherein the controller forms a compensated current sense signal that varies a value of the compensated current sense signal around a value of the current sense signal while operating in the discontinuous current mode;
- and
- configuring the controller to transition from the continuous current mode to the discontinuous current mode in response to a continuous current mode cycle in which the controller does not does not vary the frequency, including forming the controller to vary the compensated current sense signal oppositely to a variation of the frequency of the switching drive signal in response to changing from the continuous current mode to the discontinuous current mode.
Dependencies are inferred from the claim text.