Clamping Apparatus And Method
AssigneeContinental Automotive Systems, Inc.
InventorSergio Adolfo Elias-Palacios
Life of this patent
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Abstract
A protection circuit protects transistors in a DC-DC conversion circuit from over voltages. The transistors in the conversion circuit include first and second transistors. Converted energy is driven across a transformer by an H-bridge circuit. With a first configuration of the H-bridge circuit, a third transistor is turned on to discharge an inductor that was previously charged. The inductor is coupled to the third transistor. The discharging of the inductor boosts an output current of the conversion circuit. A capacitor is charged through a diode. The capacitor and diode are disposed in the protection circuit. The diode is coupled to the first transistor and the charging of the capacitor is effective to limit voltage across the first transistor.
Claims16
A method of protecting transistors in a DC-DC conversion circuit, the transistors in the conversion circuit including a first transistor and a second transistor, converted energy being driven across a transformer by an H-bridge circuit, the method comprising:
- with a first configuration of the H-bridge circuit:
- turning on a third transistor in a protection circuit to discharge an inductor in the DC-DC conversion circuit that was previously charged, the inductor coupled to the third transistor, the discharging of the inductor boosting an output current of the conversion circuit;
- charging a capacitor through a diode, the capacitor and diode being disposed in the protection circuit, the diode being coupled to the first transistor, the charging of the capacitor being effective to limit voltage across the first transistor.
A DC-DC conversion circuit, comprising:
- a first transistor and a second transistor for receiving converted energy being across a transformer from an H-bridge circuit, the first transistor and the second transistor being coupled to a load;
- an inductor;
- a protection circuit coupled to the first transistor and the second transistor, the protection circuit including a third transistor, a capacitor, and a diode, the diode being coupled to the first transistor;
- wherein with a first configuration of the H-bridge circuit, the third transistor in the protection circuit is turned on to discharge the inductor that was previously charged, the being inductor coupled to the third transistor, the discharging of the inductor boosting an output current of the conversion circuit, wherein the capacitor is charged through a diode, the capacitor and diode being disposed in the protection circuit, the charging of the capacitor being effective to limit voltage across the first transistor.
Dependencies are inferred from the claim text.