Back to results
US 8,711,578 B2Granted
Method of forming a power supply controller and structure therefor
AssigneeSemiconductor Components Industries, LLC
InventorJoel Turchi
Life of this patent
Estimating the term…
Abstract
In one embodiment, a power supply controller is configured to adjust a peak value of a primary current through a power switch responsively to a difference between a demagnetization time and a discharge time of the parasitic leakage inductance of a transformer.
Claims20
A power supply controller comprising:
- a switching control circuit configured to form a switching control signal to control a power switch to regulate an output current through a transformer to a desired value, the switching control signal having a period, the transformer including a secondary winding to conduct a secondary current, the transformer also including an auxiliary winding to form an auxiliary voltage, and the transformer further including a parasitic leakage inductance;
- a demag detect circuit configured to receive a signal representative of the auxiliary voltage and form a zero detect signal representative of a demagnetization time of the transformer;
- a leakage detect circuit configured to form a leakage reset signal responsively to completion of a discharge time of the parasitic leakage inductance;
- a compensation circuit configured to receive the leakage reset signal and the zero detect signal and form a compensation control signal that is representative of a difference between the demagnetization time and the discharge time of the parasitic leakage inductance;
- and
- a reference generation circuit configured to use the compensation control signal to form a current reference signal having a value that varies responsively to the compensation control signal wherein the switching control circuit adjusts an ON-time of the power switch responsively to changes of the current reference signal.
3 more elements
A method of forming a power supply controller comprising:
- forming the power supply controller to form a switching control signal to control a power switch to regulate an output current through a transformer to a desired value wherein the transformer includes a secondary winding to conduct a secondary current, and a parasitic leakage inductance;
- configuring the power supply controller to form a first signal representative of a demagnetization time of the transformer and to form a second signal representative of a discharge time of the parasitic leakage inductance;
- configuring the power supply controller to use the first signal and the second signal to form a third signal that is representative of a difference between the demagnetization time and the discharge time of the parasitic leakage inductance;
- and
- configuring a first circuit of the power supply controller to use the third signal to adjust an ON-time of the power switch responsively to the difference between the demagnetization time and the discharge time of the parasitic leakage inductance.
2 more elements
A method of forming a power supply controller comprising:
- forming the power supply controller to form a switching control signal to control a power switch to regulate an output current through a transformer to a desired value wherein the transformer includes a secondary winding to conduct a secondary current, and a parasitic leakage inductance;
- forming the power supply controller to sense a demagnetization time of the transformer;
- forming power supply controller to sense a discharge time of the parasitic leakage inductance;
- and
- forming the power supply controller to adjust a peak value of a primary current through the power switch responsively to a difference between the demagnetization time and the discharge time of the parasitic leakage inductance.
2 more elements
Dependencies are inferred from the claim text.