Proactively operational over-voltage protection circuit
First Claim
1. An over-voltage protection loop for a transformer, the transformer to include a primary clock and feedback control circuit, a main servo loop circuit, and the over-voltage protection loop, the over-voltage protection loop comprising:
- an over-voltage winding magnetically coupled to a magnetic core, the over-voltage winding which, in response to a voltage on a primary winding in the primary clock and feedback control circuit, is activated to provide a secondary side voltage supply;
an error amplifier electrically coupled to a first node and a second node, wherein the error amplifier uses the secondary side voltage supply to maintain a voltage on the second node according to an internal reference voltage;
a feedback impedance electrically coupled between the first node and the second node, the feedback impedance which introduces a time delay to provide feedback from the first node to the second node; and
an output voltage sensing circuit electrically coupled to at least the second node and a output node, the output voltage sensing circuit which controls an output voltage at the output node based on the voltage at the second node,wherein the over-voltage protection loop provides the output voltage for the transformer under an error condition.
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Accused Products
Abstract
Systems and methods are disclosed for providing over-voltage protection for power converters. An over-voltage protection loop includes an error amplifier that maintains an external reference voltage within a highly precise range that can be used to provide a highly precise output voltage from the over-voltage protection loop. The over-voltage protection loop may also include feedback impedance that delays the output of the over-voltage protection loop. The delay may prevent the over-voltage protection loop from being engaged due to voltage transients output from a main servo loop circuit that provides a nominal output voltage under normal operation, thus allowing the threshold voltage and output voltage of the over-voltage protection loop to be set close to the nominal output voltage of the main servo loop circuit.
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Citations
10 Claims
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1. An over-voltage protection loop for a transformer, the transformer to include a primary clock and feedback control circuit, a main servo loop circuit, and the over-voltage protection loop, the over-voltage protection loop comprising:
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an over-voltage winding magnetically coupled to a magnetic core, the over-voltage winding which, in response to a voltage on a primary winding in the primary clock and feedback control circuit, is activated to provide a secondary side voltage supply; an error amplifier electrically coupled to a first node and a second node, wherein the error amplifier uses the secondary side voltage supply to maintain a voltage on the second node according to an internal reference voltage; a feedback impedance electrically coupled between the first node and the second node, the feedback impedance which introduces a time delay to provide feedback from the first node to the second node; and an output voltage sensing circuit electrically coupled to at least the second node and a output node, the output voltage sensing circuit which controls an output voltage at the output node based on the voltage at the second node, wherein the over-voltage protection loop provides the output voltage for the transformer under an error condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification