Advanced Circuit Design and Implementation of a Highly Digitalized Third-Order VCO-Based Sigma-Delta Modulator With Enhanced Noise Transfer Function
This study proposes an advanced circuit design to implement a highly digitalized current input third-order sigma-delta modulator (SDM) with enhanced noise transfer function (NTF). The proposed current input SDM can directly quantize current-type signals without any trans-impedance amplifier. Noise s...
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IEEE
2025-01-01
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| Online Access: | https://ieeexplore.ieee.org/document/10843677/ |
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| author | Shuenn-Yuh Lee Yi-Ting Hsieh Ju-Yi Chen |
| author_facet | Shuenn-Yuh Lee Yi-Ting Hsieh Ju-Yi Chen |
| author_sort | Shuenn-Yuh Lee |
| collection | DOAJ |
| description | This study proposes an advanced circuit design to implement a highly digitalized current input third-order sigma-delta modulator (SDM) with enhanced noise transfer function (NTF). The proposed current input SDM can directly quantize current-type signals without any trans-impedance amplifier. Noise shaping with the proposed third-order SDM is realized via a passive integrator and two-stage voltage-controlled oscillator (VCO) phase integrators, which make the circuit structure highly digitalized and benefit from evolutionary fabrication techniques. The second VCO phase integrator can be easily realized by a current-steering digital-to-analog converter (I-DAC) because of the digital output from the previous phase integrator. This I-DAC is also used as the feedback path to develop current subtraction. A zero is implemented in the transfer function to establish the Chebyshev transfer function and further increase the resolution of the proposed SDM by the enhanced NTF. Measurement results reveal that the proposed highly digitalized SDM has a signal-to-noise and distortion ratio (SNDR) of 80.35 dB in the 10 kHz bandwidth and consumes <inline-formula> <tex-math notation="LaTeX">$67.34~\mu $ </tex-math></inline-formula>W under a supply voltage of 1.2 V, achieving a peak Schreier figure of merit (FoM) of 164.7 dB. The experimental setup of the proposed analog-front-end (AFE) architecture is also presented to showcase the AFE functionality. |
| format | Article |
| id | doaj-art-01d7b5067dd944f9b2d9641d1bf8e2df |
| institution | Kabale University |
| issn | 2169-3536 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IEEE |
| record_format | Article |
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| spelling | doaj-art-01d7b5067dd944f9b2d9641d1bf8e2df2025-01-25T00:01:58ZengIEEEIEEE Access2169-35362025-01-0113125151252610.1109/ACCESS.2025.353068610843677Advanced Circuit Design and Implementation of a Highly Digitalized Third-Order VCO-Based Sigma-Delta Modulator With Enhanced Noise Transfer FunctionShuenn-Yuh Lee0https://orcid.org/0000-0002-9757-1410Yi-Ting Hsieh1https://orcid.org/0009-0009-9577-6189Ju-Yi Chen2https://orcid.org/0000-0003-2760-9978Department of Electrical Engineering, National Cheng Kung University, Tainan City, TaiwanDepartment of Electrical Engineering, National Cheng Kung University, Tainan City, TaiwanDepartment of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan City, TaiwanThis study proposes an advanced circuit design to implement a highly digitalized current input third-order sigma-delta modulator (SDM) with enhanced noise transfer function (NTF). The proposed current input SDM can directly quantize current-type signals without any trans-impedance amplifier. Noise shaping with the proposed third-order SDM is realized via a passive integrator and two-stage voltage-controlled oscillator (VCO) phase integrators, which make the circuit structure highly digitalized and benefit from evolutionary fabrication techniques. The second VCO phase integrator can be easily realized by a current-steering digital-to-analog converter (I-DAC) because of the digital output from the previous phase integrator. This I-DAC is also used as the feedback path to develop current subtraction. A zero is implemented in the transfer function to establish the Chebyshev transfer function and further increase the resolution of the proposed SDM by the enhanced NTF. Measurement results reveal that the proposed highly digitalized SDM has a signal-to-noise and distortion ratio (SNDR) of 80.35 dB in the 10 kHz bandwidth and consumes <inline-formula> <tex-math notation="LaTeX">$67.34~\mu $ </tex-math></inline-formula>W under a supply voltage of 1.2 V, achieving a peak Schreier figure of merit (FoM) of 164.7 dB. The experimental setup of the proposed analog-front-end (AFE) architecture is also presented to showcase the AFE functionality.https://ieeexplore.ieee.org/document/10843677/Analog-to-digital convertercurrent-sensing techniquevoltage-controlled oscillator-based sigma-delta modulatorChebyshev transfer functionproportional-integral structureanalog front-end |
| spellingShingle | Shuenn-Yuh Lee Yi-Ting Hsieh Ju-Yi Chen Advanced Circuit Design and Implementation of a Highly Digitalized Third-Order VCO-Based Sigma-Delta Modulator With Enhanced Noise Transfer Function IEEE Access Analog-to-digital converter current-sensing technique voltage-controlled oscillator-based sigma-delta modulator Chebyshev transfer function proportional-integral structure analog front-end |
| title | Advanced Circuit Design and Implementation of a Highly Digitalized Third-Order VCO-Based Sigma-Delta Modulator With Enhanced Noise Transfer Function |
| title_full | Advanced Circuit Design and Implementation of a Highly Digitalized Third-Order VCO-Based Sigma-Delta Modulator With Enhanced Noise Transfer Function |
| title_fullStr | Advanced Circuit Design and Implementation of a Highly Digitalized Third-Order VCO-Based Sigma-Delta Modulator With Enhanced Noise Transfer Function |
| title_full_unstemmed | Advanced Circuit Design and Implementation of a Highly Digitalized Third-Order VCO-Based Sigma-Delta Modulator With Enhanced Noise Transfer Function |
| title_short | Advanced Circuit Design and Implementation of a Highly Digitalized Third-Order VCO-Based Sigma-Delta Modulator With Enhanced Noise Transfer Function |
| title_sort | advanced circuit design and implementation of a highly digitalized third order vco based sigma delta modulator with enhanced noise transfer function |
| topic | Analog-to-digital converter current-sensing technique voltage-controlled oscillator-based sigma-delta modulator Chebyshev transfer function proportional-integral structure analog front-end |
| url | https://ieeexplore.ieee.org/document/10843677/ |
| work_keys_str_mv | AT shuennyuhlee advancedcircuitdesignandimplementationofahighlydigitalizedthirdordervcobasedsigmadeltamodulatorwithenhancednoisetransferfunction AT yitinghsieh advancedcircuitdesignandimplementationofahighlydigitalizedthirdordervcobasedsigmadeltamodulatorwithenhancednoisetransferfunction AT juyichen advancedcircuitdesignandimplementationofahighlydigitalizedthirdordervcobasedsigmadeltamodulatorwithenhancednoisetransferfunction |