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US 12,658,819 B2Granted
Method to maintain synchronous rectification at light loads
AssigneeSTMicroelectronics Asia Pacific Pte Ltd
InventorKien Beng Tan
Life of this patent
Estimating the term…
Abstract
An electronic device includes a synchronous rectifier and a battery. The synchronous rectifier outputs a charging current to the battery. The electronic device includes rectifier controller that adjusts a resistance of a switch of the rectifier based on a magnitude of the charging current.
Claims22
A device, comprising:
- a rectifier including:
- a first input configured to receive a first AC voltage;
- a second input configured to receive a second AC voltage;
- an output configured to output a rectified voltage;
- a first switch coupled between the first input and ground and having a variable resistance;
- a first diode coupled in parallel with the first switch;
- a second switch coupled between the output of the rectifier and the second input;
- a second diode coupled in parallel with the second switch;
- a comparator having an output coupled to a control terminal of the first switch and configured to enable and disable the first switch;
- and
- a level shifter having an input coupled to the output of the comparator and the control terminal of the first switch and an output coupled to a control terminal of the second switch and configured to enable and disable the second switch;
- a current sensor coupled to the output of the rectifier;
- and
- a rectifier controller coupled to an output of the current sensor and to the first switch.
11 more elements
A device, comprising:
- a rectifier, including:
- a first input configured to receive a first AC voltage;
- a second input configuration to receive a second AC voltage;
- an output configured to output a rectified voltage;
- a first switch coupled between the first AC voltage and ground;
- a first comparator having an output coupled to a gate terminal of the first switch;
- a second switch coupled between the output of the rectifier and the second input;
- a third switch;
- a first diode coupled in parallel with the first switch;
- a second diode coupled in parallel with the second switch;
- a third diode coupled in parallel with the third switch;
- and
- a first level shifter having an input coupled to the output of the comparator and to the gate terminal of the first switch, and a first level shifter output coupled to a gate terminal of the second switch.
10 more elements
A method, comprising:
- receiving a first AC voltage at a first input of a rectifier;
- receiving a second AC voltage at a second input of the rectifier;
- outputting a rectified voltage from an output of the rectifier based on the first AC voltage and the second AC voltage;
- outputting a DC current with the output of the rectifier;
- sensing a magnitude of the DC current;
- adjusting a resistance of a first switch of the rectifier based on the magnitude of the DC current, the first switch being coupled between the first AC voltage and ground, a first diode being coupled in parallel with the first switch;
- controlling a gate terminal of the first switch with a comparator having an output coupled to the gate terminal of the first switch;
- controlling a second switch of the rectifier with a level shifter having an input coupled to the output of the comparator and to the gate terminal of the first switch, and a level shifter output coupled to a gate terminal of the second switch, the second switch being coupled between the output of the rectifier and the second input, a second diode being coupled in parallel with the second switch.
5 more elements
A method, comprising:
- receiving a first AC voltage at a first input of a rectifier;
- receiving a second AC voltage at a second input of the rectifier;
- outputting a DC current from an output of the rectifier;
- sensing a magnitude of the DC current;
- selectively enabling, responsive to the magnitude of the DC current, one or more of a plurality of parallel-coupled transistors of a first switch of the rectifier coupled between the first input and ground;
- controlling a gate terminal of the first switch with a comparator having an output coupled to the gate terminal of the first switch, a first diode being coupled in parallel with the first switch;
- and
- controlling a second switch of the rectifier with a level shifter having an input coupled to the output of the comparator and to the gate terminal of the first switch, and an output coupled to a gate terminal of the second switch, the second switch being coupled between the output of the rectifier and the second input, a second diode being coupled in parallel with the second switch.
5 more elements
Dependencies are inferred from the claim text.