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US 12,619,268 B2Granted
Current sensing circuit with temperature coefficient compensation
AssigneeApple Inc.
InventorsJing Xue, Chongli Cai, Ziyu Xia, Jitendra K Agrawal, Joey Yurgelon, Hao Zhou
Life of this patent
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Abstract
A current sensing circuit includes a first field-effect transistor (FET) coupled to a first current source, an inductor, and a power FET, and includes a second FET coupled to a second current source. The current sensing circuit also includes a temperature circuit coupled to the first FET and the second FET. The temperature circuit is configured to compensate for one or more differences between one or more temperature coefficients of one or more of the first FET, the second FET, and the power FET.
Claims20
An apparatus, comprising:
- a first field-effect transistor (FET) coupled to a first current source, an inductor, and a power FET, wherein the first current source is configured to generate a first current;
- a second FET coupled to a second current source configured to generate a second current;
- and
- a temperature circuit coupled to the first FET and the second FET, wherein the temperature circuit configured to adjust a value of the second current based on respective temperature coefficients of one or more of the first FET, the second FET, and the power FET.
1 more element
A method, comprising:
- providing a first current from a first current source to a first FET, a temperature circuit, and a power FET;
- providing a second current from a second current source to a second FET and the temperature circuit;
- and
- adjusting the second current based on one or more temperature coefficients of one or more of the first FET, the second FET, and a temperature coefficient of the power FET.
1 more element
An apparatus, comprising:
- a voltage regulator circuit that includes a switch node coupled to a regulated power supply node via an inductor, wherein the voltage regulator circuit is configured to source a charge current to the switch node during a charge cycle;
- a current sensing circuit comprising:
- a first field-effect transistor (FET) coupled to a first current source, the inductor, and a power FET, wherein the first current source is configured to generate a first current;
- a second FET coupled to a second current source configured to generate a second current;
- and
- a comparator circuit coupled to the first FET and the second FET, wherein the comparator circuit is configured to:
- adjust the second current based on one or more temperature coefficients of one or more of the first FET, the second FET, and the power FET;
- and
- determine whether the charge current from the first current source matches a target current;
- and
- a control circuit configured to, in response to determining that the charge current matches the target current, start the charge cycle or stop the charge cycle.
8 more elements
Dependencies are inferred from the claim text.