Cancel voltage offset of operational amplifier
First Claim
1. A method comprising:
- determining, by a computing system, whether a voltage output from an operational amplifier in a current regulating circuit is stable, wherein stability is determined by whether the voltage output changes at a rate beyond a predetermined operational level desired for a rechargeable battery, the voltage being read by an analog-to-digital converter of the computing system, wherein the operational amplifier having a negative input to receive a pre-bias voltage, a positive input, an output, and a voltage offset, and wherein the pre-bias voltage received at the negative input of the operational amplifier is greater than half the range of the voltage offset of the operational amplifier;
responsive to determining that the voltage output from the operational amplifier in the current regulating circuit is not stable, inputting, by the computing system, a voltage input into the operational amplifier in the current regulating circuit equal to a first constant value minus the voltage output times a second constant value until the voltage output is stable; and
responsive to determining that the voltage output from the operational amplifier in the current regulating circuit is stable, storing, by the computing system, the voltage output value as a voltage bias value to cancel an offset of the current regulating circuit.
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Accused Products
Abstract
A system according to examples of the present disclosure includes a battery charger electrically coupled to a battery and a battery charging circuit. The battery charging circuit includes an operational amplifier having a negative input to receive a pre-bias voltage, a positive input, an output, and a voltage offset. The battery charging circuit also includes a charge controller having an analog-to-digital converter to receive a voltage output from the output of the operational amplifier and a voltage supply to supply a voltage input into the positive input of the operation amplifier to cancel the voltage offset of the operational amplifier. In the example, the voltage output of the charge controller is a function of the voltage input of the charge controller.
17 Citations
15 Claims
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1. A method comprising:
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determining, by a computing system, whether a voltage output from an operational amplifier in a current regulating circuit is stable, wherein stability is determined by whether the voltage output changes at a rate beyond a predetermined operational level desired for a rechargeable battery, the voltage being read by an analog-to-digital converter of the computing system, wherein the operational amplifier having a negative input to receive a pre-bias voltage, a positive input, an output, and a voltage offset, and wherein the pre-bias voltage received at the negative input of the operational amplifier is greater than half the range of the voltage offset of the operational amplifier; responsive to determining that the voltage output from the operational amplifier in the current regulating circuit is not stable, inputting, by the computing system, a voltage input into the operational amplifier in the current regulating circuit equal to a first constant value minus the voltage output times a second constant value until the voltage output is stable; and responsive to determining that the voltage output from the operational amplifier in the current regulating circuit is stable, storing, by the computing system, the voltage output value as a voltage bias value to cancel an offset of the current regulating circuit. - View Dependent Claims (2, 3, 4, 5)
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6. A computing system comprising:
a battery charger electrically coupled to a battery and a battery charging circuit, the battery charging circuit further comprising; an operational amplifier having a negative input to receive a pre-bias voltage, a positive input, an output, and a voltage offset, wherein the pre-bias voltage received at the negative input of the operational amplifier is greater than the half the range of the voltage offset of the operational amplifier; and a charge controller having an analog-to-digital converter to receive a voltage output from the output of the operational amplifier and a voltage supply to supply a voltage input into the positive input of the operation amplifier to cancel the voltage offset of the operational amplifier, wherein the charge controller determines whether the voltage output from the operational amplifier in the battery charging circuit is stable, wherein stability is determined by whether the voltage output changes at a rate beyond a predetermined operational level desired for a rechargeable battery, and wherein the voltage output of the charge controller is a function of the voltage input of the charge controller. - View Dependent Claims (7, 8)
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9. A method, comprising:
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initiating, by a computing system, a battery charging for a rechargeable battery; calibrating, by the computing system, a battery charging circuit, the battery charging circuit further comprising; an operational amplifier having a negative input to receive a pre-bias voltage, a positive input, an output, and a voltage offset, wherein the pre-bias voltage received at the negative input of the operational amplifier is greater than the half the range of the voltage offset of the operational amplifier, and a charge controller having an analog-to-digital converter to receive a voltage output from the output of the operational amplifier and a voltage supply to supply a voltage input into the positive input of the operation amplifier, wherein the charge controller determines whether the voltage output from the operational amplifier in the battery charging circuit is stable, wherein stability is determined by whether the voltage output changes at a rate beyond a predetermined operational level desired for the rechargeable battery; determining, by the computing system, a desired charge current for the battery charging circuit; applying, by the computing system, the desired charge current to the battery charging circuit to cancel the voltage offset of the battery charging circuit; and supplying, by the computing system, a battery charging current to the battery. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification