A High SNR Improvement CMOS Analog Accumulator with Charge Compensation Technique
Zhongjie Guo1, Chen Li1, Ruiming Xu1
1Department of Electronic Engineering, Xi'an University of Technology, No. 5 Jinhua South Road, Xi'an 710054, China.
Sensors (Basel, Switzerland)
|September 23, 2022
Summary
This study introduces a 128-stage analog Time Delay Integration (TDI) CMOS accumulator. Adaptive compensation techniques significantly improve the signal-to-noise ratio (SNR) by reducing charge loss in analog circuits.
Area of Science:
- Analog integrated circuit design
- CMOS technology
- Signal processing
Background:
- Parasitic effects in analog circuits cause charge loss, degrading signal quality.
- Time Delay Integration (TDI) is crucial for enhancing signal-to-noise ratio (SNR) in imaging and sensing applications.
- Existing analog accumulators face challenges in compensating for charge loss.
Purpose of the Study:
- To propose and verify an analog domain Time Delay Integration (TDI) CMOS analog accumulator with 128 stages.
- To implement an adaptive compensation technique for charge loss caused by parasitic effects.
- To demonstrate significant SNR improvement in the proposed 128-stage accumulator.
Main Methods:
- Design of a 7.75 kHz line rate, 128-stage analog domain TDI CMOS analog accumulator.
- Implementation of an adaptive compensation mechanism utilizing alternate charging of capacitor plates and a positive feedback capacitor.
- Post-layout simulation to verify the circuit's performance and effectiveness.
Main Results:
- The proposed circuit successfully compensates for charge loss during sampling and holding phases.
- Post-layout simulations confirmed the effectiveness of the adaptive compensation technique.
- A significant SNR improvement of up to 20.9 dB was achieved for the 128-stage accumulation.
Conclusions:
- The developed analog domain TDI CMOS accumulator effectively mitigates parasitic effects.
- The adaptive compensation strategy provides substantial SNR enhancement in multi-stage analog accumulators.
- This work offers a promising solution for improving performance in analog signal processing systems.
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