Multi-Point Chopper Amplifier Offset Correction Without Ripple
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Solution Overview
Problem
Conventional chopper amplifiers face challenges in effectively reducing input offset voltage and low-frequency noise, which can result in output chopping ripple and require complex compensation paths, increasing power consumption and component count, while also being inefficient in low-power applications.
Innovation Solution
A chopper amplifier with multiple sensing points and a multi-point sensed offset correction circuit that generates an input offset compensation signal based on signal levels at various points along the signal path, injecting it to compensate for input offset voltage and suppress output chopping ripple, thereby avoiding the need for high-frequency feedforward compensation paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional chopper amplifiers use complex compensation paths to reduce input offset voltage and low-frequency noise, then offset voltage is reduced, but power consumption and device complexity increase
Solution Approach 1:
The patent segments the offset correction process into multiple sensing points along the signal path (input stage, intermediate stage, output stage). Each sensing point independently measures offset voltage, allowing distributed correction without requiring a single complex compensation path. This segmentation reduces both device complexity and power consumption while maintaining offset correction effectiveness.
2Object-generated harmful factors
If conventional chopper amplifiers use complex compensation paths to suppress output chopping ripple, then ripple is reduced, but power consumption increases
Solution Approach 1:
The patent implements preliminary offset correction at multiple sensing points before the offset voltage propagates through the amplification stages. By detecting and correcting offset voltage at the input stage and intermediate stages, the system prevents the generation of chopping ripple at the output, eliminating the need for complex post-correction compensation paths and reducing power consumption.
3Measurement precision
If conventional chopper amplifiers use high-frequency feedforward compensation paths, then offset correction is achieved, but device complexity and power consumption increase
Solution Approach 1:
The patent replaces high-frequency feedforward compensation paths with feedback-based offset correction at multiple sensing points. Each sensing point uses feedback mechanisms to detect offset voltage and generate correction signals that are applied back to the amplification stages. This feedback approach achieves effective offset correction with simpler circuitry and lower power consumption compared to feedforward paths.
Data Source
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AI summary
Chopper amplifiers with multiple sensing points for correcting input offset are disclosed herein. In certain embodiments, a chopper amplifier includes chopper amplifier circuitry including an input chopping circuit, an amplification circuit, and an output chopping circuit electrically connected in a cascade along a signal path. The chopper amplifier further incudes a multi-point sensed offset correction circuit that generates an input offset compensation signal based on sensing a signal level of the signal path at multiple signal points. Furthermore, the multi-point sensed offset correction circuit injects the input offset compensation signal into the signal path to thereby compensate for input offset voltage of the amplification circuit while suppressing output chopping ripple from arising.