A Calibration-Free Digital-to-Time Converter for Phase Interpolation-Based Fractional-N PLLs

In this paper, a fractional frequency division phase-locked loop based on phase interpolation is proposed and implemented using the TSMC 0.11 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sa...

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Main Authors: Weishuang Liang, Qi Liu, Yebing Gan
Format: Article
Language:English
Published: MDPI AG 2023-02-01
Series:Electronics
Subjects:
Online Access:https://www.mdpi.com/2079-9292/12/4/841
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author Weishuang Liang
Qi Liu
Yebing Gan
author_facet Weishuang Liang
Qi Liu
Yebing Gan
author_sort Weishuang Liang
collection DOAJ
description In this paper, a fractional frequency division phase-locked loop based on phase interpolation is proposed and implemented using the TSMC 0.11 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>m CMOS process. Compared with the conventional phase-locked loop, a digital time converter (DTC) module is added to this phase-locked loop, and the DTC module can reduce the fractional spurious by phase interpolation. The circuit and analysis method of this DTC module are given in this paper. Unlike the existing approaches, the proposed DTC is calibration-free, and the error introduced by it is only related to the DAC adopted in the DTC. In addition, the accuracy of the DTC is 8 bits. Finally, this paper verifies the proposed quantization noise reduction technique using a 0.11 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>m CMOS process. The proposed FNPLL achieves the overall power consumption of 20.3 mW, the noise of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo><mn>117</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>dBc/Hz@1 MHz and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo><mn>138</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>dBc/Hz<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mspace width="4pt"></mspace><mo>@</mo><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>10 MHz, and the RMS jitter of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.860</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>ps. The area of the proposed FDIV is <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>60</mn><mo>×</mo><mn>245</mn><mspace width="4pt"></mspace><mi mathvariant="sans-serif">μ</mi></mrow></semantics></math></inline-formula>m<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mn>2</mn></msup></semantics></math></inline-formula>, and the power consumption is <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>1.356</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>mW. The phase noise of the proposed FNPLL in the fractional division mode is just <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>dB higher than that in the integer division mode.
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spelling doaj.art-d14cedfea05c4e33922a641a4cd35d672023-11-16T20:10:50ZengMDPI AGElectronics2079-92922023-02-0112484110.3390/electronics12040841A Calibration-Free Digital-to-Time Converter for Phase Interpolation-Based Fractional-N PLLsWeishuang Liang0Qi Liu1Yebing Gan2Institute of Microelectronics of the Chinese Academy of Sciences, Beijing 100029, ChinaInstitute of Microelectronics of the Chinese Academy of Sciences, Beijing 100029, ChinaInstitute of Microelectronics of the Chinese Academy of Sciences, Beijing 100029, ChinaIn this paper, a fractional frequency division phase-locked loop based on phase interpolation is proposed and implemented using the TSMC 0.11 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>m CMOS process. Compared with the conventional phase-locked loop, a digital time converter (DTC) module is added to this phase-locked loop, and the DTC module can reduce the fractional spurious by phase interpolation. The circuit and analysis method of this DTC module are given in this paper. Unlike the existing approaches, the proposed DTC is calibration-free, and the error introduced by it is only related to the DAC adopted in the DTC. In addition, the accuracy of the DTC is 8 bits. Finally, this paper verifies the proposed quantization noise reduction technique using a 0.11 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>m CMOS process. The proposed FNPLL achieves the overall power consumption of 20.3 mW, the noise of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo><mn>117</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>dBc/Hz@1 MHz and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>−</mo><mn>138</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>dBc/Hz<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mspace width="4pt"></mspace><mo>@</mo><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>10 MHz, and the RMS jitter of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.860</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>ps. The area of the proposed FDIV is <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>60</mn><mo>×</mo><mn>245</mn><mspace width="4pt"></mspace><mi mathvariant="sans-serif">μ</mi></mrow></semantics></math></inline-formula>m<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mn>2</mn></msup></semantics></math></inline-formula>, and the power consumption is <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>1.356</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>mW. The phase noise of the proposed FNPLL in the fractional division mode is just <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2</mn><mspace width="4pt"></mspace></mrow></semantics></math></inline-formula>dB higher than that in the integer division mode.https://www.mdpi.com/2079-9292/12/4/841phase interpolationfractional-N dividerDTCphase adjustdelta-sigma modulator
spellingShingle Weishuang Liang
Qi Liu
Yebing Gan
A Calibration-Free Digital-to-Time Converter for Phase Interpolation-Based Fractional-N PLLs
Electronics
phase interpolation
fractional-N divider
DTC
phase adjust
delta-sigma modulator
title A Calibration-Free Digital-to-Time Converter for Phase Interpolation-Based Fractional-N PLLs
title_full A Calibration-Free Digital-to-Time Converter for Phase Interpolation-Based Fractional-N PLLs
title_fullStr A Calibration-Free Digital-to-Time Converter for Phase Interpolation-Based Fractional-N PLLs
title_full_unstemmed A Calibration-Free Digital-to-Time Converter for Phase Interpolation-Based Fractional-N PLLs
title_short A Calibration-Free Digital-to-Time Converter for Phase Interpolation-Based Fractional-N PLLs
title_sort calibration free digital to time converter for phase interpolation based fractional n plls
topic phase interpolation
fractional-N divider
DTC
phase adjust
delta-sigma modulator
url https://www.mdpi.com/2079-9292/12/4/841
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