Circuit and method for a high common mode rejection amplifier by using a digitally controlled gain trim circuit
AssigneeDialog Semiconductor (UK) Limited
InventorsZakaria Mengad, Steven Collins, Vladislav Vasilev
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Abstract
An amplifier comprising a differential amplifier configured to be provide a comparator function, and a gain trimming circuit is electrically configured to provide gain trimming using a T-network comprising a varistor element. In addition, a method of trimming the gain of a differential amplifier, comprising the steps of a first step, (a) providing the differential amplifier comprising resistors in both of its paths, a second step, (b) providing a varistor in a T-network between both said paths; and lastly, a third step, (c) trimming the gain of the differential amplifier by adjusting the varistor's resistance.
Claims17
A differential amplifier with high common mode rejection, comprising:
- resistors in both paths of said differential amplifier wherein said differential amplifier comprises a pair of said resistors in each of its feedback paths;
- and
- a varistor in a T-network between said both said feedback paths, to provide gain trimming;
- and
- wherein said varistor is connected between each pair of said resistors.
A method of trimming gain of a differential amplifier, comprising the steps of:
- (a) wherein said a differential amplifier comprises resistors in both of its paths wherein said differential amplifier comprises a pair of said resistors in each of its feedback paths;
- (b) connecting a varistor in a T-network between both said feedback paths, wherein said varistor is connected between each pair of said resistors;
- (c) trimming the gain of said differential amplifier by adjusting resistance of said varistor.
A differential amplifier with high common mode rejection, comprising:
- resistors in both paths of said differential amplifier wherein said differential amplifier comprises a pair of said resistors in each of its input paths;
- and
- a varistor in a T-network between said both said input paths, to provide gain trimming.
Dependencies are inferred from the claim text.