| 摘要 |
A chopper-stabilized amplifier having an additional differential amplifier stage for improved noise reduction. A main amplifier provides a fast AC path, while a nulling amplifier is used to zero out input offset voltages of both the main amplifier and itself. An additional differential amplifier stage precharges the nulling amplifier within an offset compensating loop to a predetermined voltage such that when the nulling amplifier is switched into the main amplifier's loop, it contributes no unwanted noise at the output of the main amplifier. An additional pair of switches activated by an additional phase of the chopper clock insert the precharge differential amplifier into the circuit at the appropriate time.
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