Active bridge rectification
AssigneeLinear Technology Corporation
InventorsJeffrey Lynn Heath, Kirk Su, John Stineman
Life of this patent
Estimating the term…
Abstract
Technique for controlling a circuit that converts an AC input voltage into a DC output voltage using transistors arranged in first and second transistor pairs. Each transistor of the first pair is controlled in accordance with polarity of the AC input voltage. Each transistor of the second pair is controlled based on a difference between the AC input voltage and the DC output voltage.
Claims25
A system for converting an AC input voltage into a DC output voltage, comprising:
- first and second transistors arranged in a first transistor pair,
- third and fourth transistors arranged in a second transistor pair, and
- a controller responsive to the input voltage and the output voltage to control switching of the first, second, third and fourth transistors,
- the controller including an AC polarity detect circuit for determining polarity of the AC input voltage to produce a first enabling signal that enables the first transistor to turn on.
A system for converting an AC input voltage into a DC output voltage, comprising:
- first and second transistors arranged in a first transistor pair,
- third and fourth transistors arranged in a second transistor pair, and
- a controller responsive to the AC input voltage and the DC output voltage to control switching of the first, second, third and fourth transistors,
- the controller including a transistor control circuit for turning on the third transistor based on a difference between the AC input voltage and the DC output voltage, the transistor control circuit being configured for producing a first lock out signal asserted to prevent the fourth transistor from turning on when the third transistor is on.
A method of controlling a circuit for converting an AC input voltage into a DC output voltage that has first and second transistors arranged in a first transistor pair, and third and fourth transistors arranged in a second transistor pair;
- the method comprising the steps of:
- controlling a transistor of the first pair in accordance with polarity of the AC input voltage, and
- controlling a transistor of the second pair based on a difference between the AC input voltage and the DC output voltage.
A system for converting an AC input voltage into a DC output voltage, comprising:
- first and second input nodes for providing the AC input voltage,
- first and second transistors arranged in a first transistor pair,
- third and fourth transistors arranged in a second transistor pair, and
- a controller responsive to the input voltage and the output voltage to control switching of the first, second, third and fourth transistors,
- the controller being configured for:
- producing a first turn on signal for turning on the third transistor coupled to the first input node when a difference between a first voltage developed at the first input node and the output voltage exceeds a first turn on value,
- producing a first regulate signal for controlling the third transistor to maintain the difference between the first voltage and the output voltage at a first regulate value lower than the first turn on value, and
- producing a first turn off signal for turning off the third transistor when the difference between the first voltage and the output voltage falls below a first turn off value lower than the first regulate value.
Dependencies are inferred from the claim text.