Control device for rectifiers of switching converters
AssigneeSTMicroelectronics S.r.l.
InventorsAlberto Iorio, Jeanpierre Vicquery
Life of this patent
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Abstract
A control device controls a rectifier of a switching converter that is supplied with an input voltage and provides an output current. The rectifier is configured to rectify the output current of the converter and has at least one transistor. The control device, when the at least one transistor is turned off, provides a slow discharge path to ground in a normal operation condition and provides a fast discharge path to ground for discharging the control terminal of the at least one transistor in response to detecting a zero cross event of the current flowing through said at least one transistor.
Claims20
A control device for a rectifier of a switching converter, said control device comprising:
- a zero crossing detector configured to detect a zero crossing of a current through a rectifier transistor of the rectifier and output a zero crossing signal indicating a detection of the zero crossing;
- a selectable slow discharge path configured to discharge a control terminal of the rectifier transistor to ground;
- a selectable fast discharge path configured to discharge the control terminal of the rectifier transistor to ground more quickly than the slow discharge path;
- and
- a controller configured to enable the slow discharge path to discharge the control terminal of the rectifier transistor in a normal operation condition and enable the fast discharge path to discharge the control terminal of the rectifier transistor in response to the zero crossing signal indicating the zero crossing of the current through said rectifier transistor.
A switching resonant converter, comprising:
- a transformer configured to provide an output current of the converter, said transformer including a primary winding and a secondary winding;
- a rectifier coupled to the secondary winding and configured to rectify said output current of the converter, said rectifier including a rectifier transistor;
- and
- a control device configured to control the rectifier and including:
- a zero crossing detector configured to detect a zero crossing of a current through the rectifier transistor and output a zero crossing signal indicating a detection of the zero crossing;
- a selectable slow discharge path configured to discharge a control terminal of the rectifier transistor to ground;
- a selectable fast discharge path configured to discharge the control terminal of the rectifier transistor to ground more quickly than the slow discharge path;
- and
- a controller configured to enable the slow discharge path to discharge the control terminal of the rectifier transistor in a normal operation condition and enable the fast discharge path to discharge the control terminal of the rectifier transistor in response to the zero crossing signal indicating the zero crossing of the current through said rectifier transistor.
A control method, comprising:
- controlling a rectifier of a switching converter that is configured to provide an output current based on an input voltage, said rectifier being configured to rectify the output current of the converter and having a rectifier transistor, the controlling including:
- providing a slow discharge path from a control terminal of the rectifier transistor to ground in a normal operation condition when the rectifier transistor is turned off;
- detecting a zero crossing of a current through the rectifier transistor;
- and
- providing a fast discharge path from the control terminal of the rectifier transistor to ground in response to detecting the zero crossing of the current through said rectifier transistor, the fast discharge path discharging the control terminal more quickly than the slow discharge path.
Dependencies are inferred from the claim text.