Equalizer Group Delay Compensation Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional equalizer circuits face signal distortion due to group delay, which is exacerbated by parasitic resistance and capacitance, limiting manufacturing process margins and affecting electric characteristics.
Innovation Solution
An equalizer circuit design incorporating a first low pass filter, a gain control circuit, and a group delay compensation circuit connected in parallel, with a second low pass filter, to modulate the gain of the transfer function and compensate for group delay, thereby reducing surface area on a semiconductor substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transconductor and capacitor are added to compensate for parasitic resistance and capacitance, then group delay characteristics are improved, but the area occupied on the semiconductor substrate increases
Solution Approach 1:
The patent combines the group delay compensation function and gain modulation function into a single integrated circuit structure. The transconductor's output is directly connected to one plate of the capacitor, merging what would traditionally be separate compensation and gain control stages into one compact unit, thereby reducing overall substrate area while maintaining both functions.
Solution Approach 2:
The capacitor in the patent serves dual purposes: it provides group delay compensation by counteracting parasitic effects, and simultaneously enables gain modulation when combined with the transconductor. This multi-functionality eliminates the need for separate components, reducing the total area required on the semiconductor substrate.
2Manufacturing precision
If transconductance is matched with capacitor to reduce transfer function error, then manufacturing precision is improved, but process margins are limited and electric characteristics cannot be guaranteed
Solution Approach 1:
The patent employs a feedback mechanism where the capacitor is connected back to the transconductor's output, creating a closed-loop system. This feedback structure automatically compensates for variations in transconductance values caused by manufacturing tolerances, ensuring consistent transfer function performance without requiring precise matching and thereby maintaining process margins.
3Reliability
If group delay compensation is implemented using conventional biquadratic filter structure, then signal distortion is reduced, but device complexity increases
Solution Approach 1:
The patent segments the equalizer circuit into distinct functional blocks: a first low-pass filter for initial signal conditioning, a transconductor-capacitor combination for group delay compensation and gain modulation, and a second low-pass filter for final output conditioning. This segmentation allows each block to be optimized independently, reducing overall complexity compared to a monolithic biquadratic filter while achieving the same distortion reduction.
Data Source
AI summary
An equalizer, group delay compensation circuit for the equalizer and method of compensating for group delay may improve group delay characteristics in the equalizer. The equalizer circuit may include a first low pass filter configured to filter a received input signal to output a filtered input signal, and a gain control circuit connected to an output terminal of the first low pass filter, and configured to modulate a gain of a transfer function for the equalizer. The equalizer may include a group delay compensation circuit connected to the output terminal of the first low pass filter and configured to compensate for a group delay of the input signal, and a second low pass filter connected to the output terminal of the first low pass filter.