Adaptive blanking of transformer primary-side feedback winding signals
OwnerVijay Phadkeinventor
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Abstract
A method of regulating a power converter using a transformer primary-side feedback winding to provide a feedback signal. The feedback signal is selectively blanked based on a signal indicative of a duty cycle of a switch controlling the converter. The converter is regulated based on the selectively blanked feedback signal. The blanking is dynamically adapted to changes in the switch duty cycle.
Claims20
A method of regulating a power converter using a transformer primary-side feedback winding to provide a feedback signal, the method comprising:
- selectively blanking the feedback signal based on a signal indicative of a duty cycle of the converter;
- and
- regulating the converter based on the selectively blanked feedback signal.
A method for selectively blanking the voltage spike on a flyback feedback winding voltage used for primary side feedback regulation in a power converter having a primary and secondary winding for enabling a sensing on the primary winding side of the converter of a true reflected voltage of said secondary winding comprising:
- receiving of said flyback feedback winding voltage;
- and
- providing a blanking period for selectively filtering said flyback feedback winding voltage, said blanking period increasing with the output voltage of said converter for ensuring that any such voltage spikes on the primary and secondary winding settle;
- so as to provide a sensing on the primary side of the converter of a true reflected voltage of said secondary winding.
A method of regulating a flyback converter including a switch for switching voltage across a primary winding of the converter to regulate power to a load, the converter further including a transformer primary-side feedback winding to provide a feedback signal, the method comprising:
- selecting a reference voltage to indicate a blanking threshold for blanking a portion of the feedback signal;
- varying a voltage signal based on a duration of a pulse of the switch;
- blanking the feedback signal while the varied voltage signal exceeds the blanking threshold to filter the feedback signal;
- and
- using the filtered signal as feedback to control the switch.
A feedback control circuit for regulating voltage input to a converter having a switch that switches voltage across a primary winding of the converter, the circuit comprising:
- a primary-side feedback winding configured to produce a feedback signal;
- and
- a blanking subcircuit configured to:
- monitor a duration of a pulse of the switch;
- and
- blank a portion of the feedback signal during a blanking time period based on the monitored pulse duration.
A feedback control circuit for regulating voltage input to a flyback converter having a switch that switches voltage across a primary winding of the converter, the circuit comprising:
- a primary-side flyback feedback winding configured to produce a feedback signal;
- and
- a blanking subcircuit configured to:
- determine, based on a signal indicative of a duty cycle of the switch, a time during which to blank a portion of the feedback signal;
- and
- blank a portion of the feedback signal during the determined time period.
Dependencies are inferred from the claim text.