Chopper Amplifier Feed-Forward Offset Correction for Low Ripple
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Solution Overview
Problem
Conventional chopper-stabilized amplifiers experience input offset voltage and output voltage ripple issues due to the use of chopper circuitry, which affects their performance.
Innovation Solution
The implementation of a signal amplification block combined with a feed-forward offset correction block, which includes a feed-forward amplification circuit, a chopping circuit, and a notch filter to generate an input offset correction signal, thereby reducing the input offset voltage and output ripple.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional chopper circuitry is used to reduce input offset voltage, then input offset voltage is reduced, but output signal ripple is generated at chopping frequency and harmonics
Solution Approach 1:
The amplifier is divided into separate functional blocks: a signal amplification block and a feed-forward offset correction block. This segmentation allows independent optimization of each block's function, enabling offset correction without directly coupling the correction mechanism to the main signal path, thereby reducing ripple generation.
Solution Approach 2:
A feed-forward offset correction block is introduced as an intermediary element that generates an offset correction signal independent of the main signal path. This correction signal is then combined with the amplified signal, allowing offset voltage reduction without requiring the main amplification block to directly generate the correction, thus minimizing ripple.
2Stability of the object's composition
If chopper circuitry is added to stabilize offset voltage, then amplifier stability is improved, but device complexity increases
Solution Approach 1:
The amplifier architecture is segmented into distinct functional blocks with specialized roles. The signal amplification block handles main signal amplification while the feed-forward offset correction block handles offset compensation. This segmentation distributes complexity across modular units, making the overall system more manageable and potentially easier to implement than a monolithic chopper-stabilized design.
Solution Approach 2:
Offset correction is performed in advance through the feed-forward mechanism, where the correction signal is generated and prepared before being combined with the main amplified signal. This preliminary action allows offset compensation to be established independently, simplifying the main amplification path and reducing the complexity burden on critical signal handling components.
Data Source
AI summary
Apparatus and methods for electronic amplification are provided. In one embodiment, a method of electronic amplification includes amplifying a differential input voltage signal to generate a feed-forward signal, chopping the feed-forward signal at a chopping frequency to generate a chopped feed-forward signal, notch filtering the chopped feed-forward signal at the chopping frequency to generate a notched signal, generating an input offset correction signal based at least partly on the notched signal, and amplifying the differential input voltage signal using a signal amplification block to generate an output signal. Amplifying the differential input voltage signal using the signal amplification block includes chopping the input signal at the chopping frequency to generate a chopped input signal and combining the chopped input signal and the offset correction signal to reduce input offset error of the signal amplification block.