Compensation technique for amplifiers in a current sensing circuit for a battery

摘要

In one embodiment, a circuit includes a first amplifier having a first differential input, a second differential input, and an output. The replica device is configured to generate a replica current of a current flowing through the battery where the first amplifier controls the control device to control the replica current. The circuit also includes a second amplifier having a third differential input, a fourth differential input, and an output. The second amplifier is configured to compensate for a first offset error of the first amplifier and a second offset error of the second amplifier based on selectively coupling the third differential input to the output of the first amplifier during a first phase, selectively coupling the output of the second amplifier to the second differential input during the first phase, and selectively coupling the output of the second amplifier to the fourth differential input during a second phase.

主权项

1. A circuit comprising:
a first amplifier comprising a first differential input, a second differential input, and an output, the first differential input coupled to a replica device and a voltage of a battery and the output coupled to a control device, the replica device configured to generate a replica current of a current flowing through the battery where the first amplifier controls the control device to control the replica current; and a second amplifier comprising a third differential input, a fourth differential input, and an output, wherein the second amplifier is configured to compensate for a first offset error of the first amplifier and a second offset error of the second amplifier based on selectively coupling the third differential input to the output of the first amplifier during a first phase, selectively coupling the output of the second amplifier to the second differential input during the first phase, and selectively coupling the output of the second amplifier to the fourth differential input during a second phase.