Control device for resonant converters
AssigneeSTMicroelectronics S.r.l.
InventorClaudio Adragna
Life of this patent
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Abstract
A control device for a switching circuit of a resonant converter having a direct current at the output, the switching circuit having at least one half bridge of at least first and second transistors connected between an input voltage and a reference voltage. The half bridge is adapted to generate a periodic square wave voltage to drive the resonant circuit of the resonant converter; The control device has a circuit to proportionally generate a first voltage to a switching period, and a circuit adapted to limit the voltage at the ends of a capacitor between a reference voltage and the first voltage, and a further circuit structured to control the switching off of a first or second transistor at the time instant in which the voltage across the capacitor has reached the first voltage.
Claims35
A control device of a switching circuit for a resonant converter having at least one half-bridge of at least first and second transistors coupled between an input voltage terminal and a reference voltage terminal and to a capacitor and adapted to drive a resonant circuit of the resonant converter the control device comprising:
- a first circuit configured to synchronize a starting time instant of a time period of discharging or charging the capacitor crossing a zero value of a signal indicating the current flowing in the resonant circuit, and a second circuit structured to control the switching off of the first or the second transistor at the end of the time period of discharging or charging the capacitor, the control device structured to control the half-bridge according to the time period of charging or discharging the capacitor.
(canceled)
A method of controlling a switching circuit for a resonant converter having a direct current at the output the switching circuit having at least one half-bridge of at least first and second transistors connected between an input voltage and a reference voltage, the half-bridge structured to generate a periodic square wave voltage to drive the resonant circuit of the resonant converter, the periodic square wave voltage ranging from a high voltage corresponding to the input voltage, to a low voltage corresponding to the reference voltage, the method comprising:
- synchronizing the starting time instant of the time period of discharging or charging a capacitor crossing the value zero of a signal indicating the current flowing in the resonant circuit, and controlling the switching off of the first or the second transistor at the end of the time period of discharging or charging the capacitor.
A circuit, comprising:
- a control circuit structured to control a time period of charging and discharging a capacitor coupled to a resonant circuit, the control circuit including a first circuit structured to synchronize the a time period of charging and discharging the capacitor at a start time with a crossing of a zero value of a signal that indicates current flowing in the resonant circuit, and a second circuit structured to control a switching off of the charging or discharging of the capacitor at an end time of the charging or discharging of the capacitor.
A system comprising:
- a control device for a switching circuit for a resonant converter having a direct current at an output terminal the switching circuit including:
- at least one half-bridge circuit of at least first and second transistors connected between an input voltage terminal and a reference voltage terminal, the half bridge structured to generate a periodic square wave voltage to drive the resonant circuit for the resonant converter, the periodic square wave voltage ranging from a high voltage corresponding to the input voltage, and a low voltage corresponding to the reference voltage, the control device structured to control the half-bridge according to a time period of charging a capacitor, the control device including a circuit adapted to synchronize a starting time instant of the time period of charging the capacitor crossing a zero value of a signal indicating the current flowing in the resonant circuit and a further circuit structured to control switching off of the first or the second transistor at the end of the time period of charging the capacitor, and a generation circuit structured to proportionally generate a first voltage to the switching period, and a circuit adapted to limit a voltage at ends of the capacitor between a reference voltage and the first voltage, the further circuit structured to control the switching off of the first or second transistor of the half-bridge circuit at a time instant in which a voltage at the ends of the capacitor has reached the first voltage.
(canceled)
A circuit, comprising:
- a control circuit structured to control a time period of charging a capacitor coupled to a resonant circuit, the control circuit including a first circuit structured to synchronize a time period of charging the capacitor at a start time with a crossing of a zero value of a signal that indicates current flowing in the resonant circuit, and a second circuit structured to control a switching off of the charging of the capacitor at an end time of the charging of the capacitor in which a voltage across the capacitor is limited to range between a minimum value and a maximum value and in which charging of the capacitor is stopped when the capacitor charge reaches the maximum value.
Dependencies are inferred from the claim text.