Time-Interleaved ADC FIR Correction for Bandwidth Mismatch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed ADCs with time-interleaved architectures face challenges in correcting clock offset and bandwidth mismatch, leading to increased circuit complexity and risks of signal overflow due to high-order filter modules.
Innovation Solution
A method involving a time-interleaved ADC mismatch correction using a finite impulse response (FIR) filter and a Nelder-Mead search algorithm to calculate filtering coefficients, compensating for channel differences in frequency response rather than the response itself, reducing filter order and circuit complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-order filter modules are used to compensate channel frequency response, then bandwidth mismatch correction performance is improved, but circuit complexity increases and signal overflow risk increases
Solution Approach 1:
The patent changes the correction parameter from compensating the entire channel frequency response to compensating only the frequency response difference between channels. This parameter change allows using lower-order filters while achieving the same correction effect, thereby reducing circuit complexity and avoiding signal overflow.
Solution Approach 2:
Instead of applying uniform high-order filtering across all frequency components, the patent applies localized correction only to the frequency response differences between channels. This local quality approach uses lower-order filters targeted at specific mismatch characteristics, reducing overall circuit complexity while maintaining correction effectiveness.
2Measurement precision
If high-order filter modules are used to compensate channel frequency response, then bandwidth mismatch correction performance is improved, but signal power increases causing overflow or saturation
Solution Approach 1:
By changing the correction parameter from full frequency response compensation to frequency response difference compensation, the patent reduces the amplification of high-frequency signal power. This prevents overflow and saturation while maintaining correction performance.
Solution Approach 2:
The patent converts the harmful effect of high signal power amplification into a benefit by using lower-order filters that provide sufficient correction without excessive gain. The frequency response difference compensation approach inherently limits power amplification while still correcting the mismatch.
3Measurement precision
If high-order filter modules are used to compensate channel frequency response, then bandwidth mismatch correction performance is improved, but design difficulty increases
Solution Approach 1:
The patent simplifies design by changing the correction parameter to frequency response difference, which can be estimated and compensated using lower-order filters. This reduces design difficulty while maintaining correction effectiveness.
Data Source
AI summary
A time-interleaved ADC mismatch correction method and time-interleaved ADC relating to the technical field of integrated circuits are disclosed. The time-interleaved ADC mismatch correction method and time-interleaved ADC solve problems with high-order filter modules and signal overflow or saturation risks. The applied technical scheme uses time-interleaved ADC output signal(s) and a fitted signal to calculate a set of filtering coefficients, and uses this set of filtering coefficients to correct the ADC output signal in real time. The applied technical scheme compensates for differences in the frequency response of each channel, rather than the frequency response itself, and the filter order is smaller, the implementation is simpler, and the circuit design complexity and device cost are greatly reduced. The technical solution has a wide range of adaptability, can correct and improve broadband interleaving performance, and avoids the signal overflow/saturation risk because the compensation range is small.