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US 2020/0052500 A1Published application
Battery charging circuit
AssigneeAnpec Electronics Corporation
InventorCHIH-NING CHEN
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Abstract
A battery charging circuit adjusts a voltage proportional relationship between a turned-on voltage of a charging transistor and a turned-on voltage of a first transistor according to a first voltage corresponding to a charging current and a second voltage corresponding to the charging current, so that a ratio between the charging current and a first current sensing the charging current is a constant value or close to a constant value.
Claims10
A battery charging circuit operated in a constant current charging mode, comprising:
- a charging transistor coupled to a battery module and configured to generate a charging current flowing through the charging transistor to charge the battery module;
- a first transistor coupled to the charging transistor and generating a first current flowing through the first transistor, wherein a size of the first transistor is smaller than a size of the charging transistor, and a bulk of the first transistor is connected in series with a bulk of the charging transistor through a voltage regulator;
- a second transistor coupled to the charging transistor and generating a second current flowing through the second transistor, wherein a size of the second transistor is smaller than the size of the charging transistor and different from the size of the first transistor, and a bulk of the second transistor is connected in series with the bulk of the charging transistor;
- a first sensor coupled to the first transistor and a charging terminal between the charging transistor and the battery module, configured to generate, according to a battery voltage of the battery module, a first voltage corresponding to the charging current, and control turned-on and turned-off states of the charging transistor, the first transistor and the second transistor according to the first voltage and a reference voltage;
- and
- a second sensor coupled to the charging terminal, the second transistor and the first sensor, configured to generate, according to the battery voltage of the battery module, a second voltage corresponding to the charging current, and generate, according to the first voltage and the second voltage, a bulk voltage to apply on the bulk of the second transistor and the bulk of the charging transistor;
- wherein the voltage regulator adjusts a voltage proportional relationship between a turned-on voltage of the charging transistor and a turned-on voltage of the first transistor to stabilize a current value of the charging current.
4 more elements
Dependencies are inferred from the claim text.