Capacitive DAC Paths in ADC Circuits for Flat Wideband Response
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Solution Overview
Problem
Existing ADC circuits face challenges in achieving a flat delay profile, high gain, and wide bandwidth due to frequency-dependent attenuation and high power consumption in transimpedance and passive summation configurations, particularly in high-frequency applications.
Innovation Solution
Incorporating capacitors in the DAC paths of ADC circuits to match the capacitance of the filter, eliminating frequency-dependent attenuation and reducing power consumption by using a passive summation configuration without feedback impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transimpedance or passive summation configuration is used in ADC circuits, then conversion function is achieved, but frequency-dependent attenuation occurs and power consumption increases
Solution Approach 1:
The patent changes the electrical parameters of the DAC paths by adding capacitors in parallel with the resistors. This modifies the impedance characteristics of the DAC paths to match the filter capacitance, thereby eliminating frequency-dependent attenuation and reducing power consumption while maintaining conversion accuracy.
2Device complexity
If conventional DAC paths are used without capacitance matching, then circuit simplicity is maintained, but frequency response becomes non-flat and bandwidth is limited
Solution Approach 1:
The patent modifies the electrical parameters of the DAC paths by adding capacitors in parallel with the resistors. This changes the impedance characteristics to match the filter capacitance, thereby achieving a flat frequency response and extended bandwidth while maintaining reasonable circuit complexity.
3Manufacturing precision
If capacitance is added to DAC paths to match filter capacitance, then frequency response flatness and bandwidth improve, but device complexity increases
Solution Approach 1:
The patent combines the capacitor addition with the existing resistor structure in the DAC paths. The capacitors are added in parallel with the existing resistors, merging the capacitance function with the existing resistive DAC structure. This achieves frequency response improvement while minimizing the increase in device complexity by utilizing the existing circuit topology.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration achieves a wider unity gain bandwidth, flatter frequency response, and higher effective bandwidth, enhancing the ADC's sampled pulse response and effective number of bits, while consuming less power.
Implementation Method 1
the DAC includes one or more capacitive paths with capacitors between the input of the DAC and the output of the DAC
Data Source
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AI summary
An ADC circuit includes an ADC that converts an input analog signal to a digital signal. The ADC circuit includes a filter circuit that receives the analog input signal and provides a filtered signal to a combiner circuit. The ADC circuit includes a DAC that converts the digital signal back to an analog signal that is provided to a combiner circuit. The DAC includes one or more capacitive paths with capacitors between the input of the DAC and the output of the DAC.