eetop.cn_T6 - Front-End Circuit Design for High-Speed Optical Transceivers.pdf

1、 2025 IEEE International Solid-State Circuits ConferenceT6:Front-End Circuit Design for High-Speed Optical TransceiversPeter Ossieur(peter.ossieurimec.be)imec and Ghent University-BelgiumFebruary 16th,2025T6:Front-end circuit design for high-speed optical transceivers1 of 75Peter Ossieur 2025 IEEE I

2、nternational Solid-State Circuits ConferenceApplications for optical transceiversPeter Ossieur2 of 75DatacomInter data centerReach:10km to 80kmCapacity:10Tb/s per fiberIntra data centerReach:100m to 2kmCapacity:1Tb/s per fiberT6:Front-end circuit design for high-speed optical transceiversIntra data

3、center100m2kmInter data center 100kmIntra data center100m2km 2025 IEEE International Solid-State Circuits ConferenceApplications for optical transceiversPeter Ossieur2 of 75DatacomInter data centerReach:10km to 80kmCapacity:10Tb/s per fiberIntra data centerReach:100m to 2kmCapacity:1Tb/s per fiberTe

4、lecomMetro links:linking citiesReach:100km1000kmCapacity:100Tb/s per fiberLong haul linksReach:10010.000 kmCapacity:100Tb/s per fiberT6:Front-end circuit design for high-speed optical transceiversLong-haul or submarinelink10.000kmMetro ring network100km 1.000kmMetro ring network100km 1.000km 2025 IE

5、EE International Solid-State Circuits ConferenceApplications for optical transceiversPeter Ossieur2 of 75DatacomInter data centerReach:10km to 80kmCapacity:10Tb/s per fiberIntra data centerReach:100m to 2kmCapacity:1Tb/s per fiberTelecomFiber-to-the-homeMetro links:linking citiesReach:100km1000kmCap

6、acity:100Tb/s per fiberLong haul linksReach:10010.000 kmCapacity:100Tb/s per fiberPassive optical networksReach:up to 25kmSplit factor:up to 128Capacity:up to 50Gb/sMultipoint to point network(passiveoptical network)Up to25km reachDownstreamUpstreamOptical line terminationOptical network unitsT6:Fro

7、nt-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceQuestions addressed in this tutorialWhat are the basic components of an optical link,what are their most important parameters?How can we drive an optical modulator or laser at high-speed?

8、How can we detect and condition(amplify)an optical signal?3 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceOutlineAnatomy of an optical linkIntensity-modulated,direct-detect optical linksCoherent optical linksM

9、odulator driver circuitryLumped driver circuitsTraveling wave driver circuitsOptical receiver circuitryConclusions and upcoming research challenges4 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceOutlineAnatomy

10、 of an optical linkIntensity-modulated,direct-detect optical linksCoherent optical linksModulator driver circuitryLumped driver circuitsTraveling wave driver circuitsOptical receiver circuitryConclusions and upcoming research challenges4 of 75Peter OssieurT6:Front-end circuit design for high-speed o

11、ptical transceivers 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link5 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversElectrical(client)sideOptical(line)side 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical

12、 link5 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCMOS(DSP)chipMulti-channelDriver EICDACDACTx-DSP22Electrical(client)sideOptical(line)sideEIC:electrical integrated circuitDSP:digital signal processingDAC:digital-to-analog converterADC:analog-to-digital converte

13、r2:differential signal 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link5 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCMOS(DSP)chipMulti-channelDriver EICOptical Modulator ArrayLaserArrayDACDACTx-DSP22(MUX)Electrical(client)sideOpt

14、ical(line)sideEIC:electrical integrated circuitDSP:digital signal processingDAC:digital-to-analog converterADC:analog-to-digital converterMUX:wavelength multiplexerDeMUX:wavelength demultiplexer 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link5 of 75Peter OssieurT6:F

15、ront-end circuit design for high-speed optical transceiversCMOS(DSP)chipMulti-channelDriver EICOptical Modulator ArrayOptical Detector ArrayLaserArrayDACDACTx-DSP22(MUX)(DeMUX)Electrical(client)sideOptical(line)sideEIC:electrical integrated circuitDSP:digital signal processingDAC:digital-to-analog c

16、onverterADC:analog-to-digital converterMUX:wavelength multiplexerDeMUX:wavelength demultiplexer 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link5 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCMOS(DSP)chipMulti-channelDriver EICOpti

17、cal Modulator ArrayMulti-channelReceiver EICOptical Detector ArrayLaserArrayDACDACADCADCTx-DSPRx-DSP22(MUX)(DeMUX)22Electrical(client)sideOptical(line)sideEIC:electrical integrated circuitDSP:digital signal processingDAC:digital-to-analog converterADC:analog-to-digital converterMUX:wavelength multip

18、lexerDeMUX:wavelength demultiplexer 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD(*)linksProperties of intensity modulated,non-return to zero(NRZ)optical signals6 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers()10(*)IMDD:int

19、ensity modulation,direct detectionBit period ,=1bit rate Gb/s 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD(*)linksProperties of intensity modulated,non-return to zero(NRZ)optical signals6 of 75Peter OssieurT6:Front-end circuit design for high-speed optical t

20、ransceivers=1+02()10(*)IMDD:intensity modulation,direct detection 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD(*)linksProperties of intensity modulated,non-return to zero(NRZ)optical signals6 of 75Peter OssieurT6:Front-end circuit design for high-speed optic

21、al transceivers=1 0()=1+0210(*)IMDD:intensity modulation,direct detectionOptical modulation amplitude:2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD(*)linksProperties of intensity modulated,non-return to zero(NRZ)optical signals6 of 75Peter OssieurT6:Front-end

22、 circuit design for high-speed optical transceivers=1 0()=1+0210=10Extinction ratio:(*)IMDD:intensity modulation,direct detectionOptical modulation amplitude:2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksProperties of intensity modulated,non-return to ze

23、ro(NRZ)optical signals6 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers=1 0()=1+0210=10Extinction ratio:Optical powers usually expressed in dBm:=10log101Extinction ratio and penalties usually expressed in dB:=10log1010Optical modulation amplitude:2025 IEEE Internati

24、onal Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksProperties of intensity modulated,4-level amplitude modulated optical signals7 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers3=3+02()210Symbol period ,=14symbol rate Gbaud 4 2025 IEEE Internat

25、ional Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksProperties of intensity modulated,4-level amplitude modulated optical signals7 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers3=3+02()210=3 3 2,2 1,1 03 0Level separation mismatch ratio RLM:IE

26、EE 802.3 Clause 94,other definitions also used 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksProperties of intensity modulated,4-level amplitude modulated optical signals7 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers3

27、=3+02()210=3 3 2,2 1,1 03 0Level separation mismatch ratio RLM:IEEE 802.3 Clause 94,other definitions also usedIdeal value=1,0.95 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksDirect modulation8 of 75Peter OssieurT6:Front-end circuit design for high-spee

28、d optical transceiversSwitch ASICLaser driver or VCSEL driverLaser diode or VCSEL(*)diodeI1I010VCSEL:vertical cavity,surface emitting laserASIC:application-specific,integrated circuit 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksModulation properties of

29、 lasers and VCSELs:(V,I)curve9 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversVLASERVILASERmAILASERVLASER1/slope=differential resistance RDLasers:5 10WILASERVLASER 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksModulation

30、 properties of lasers and VCSELs:(V,I)and(P,I)curves9 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversVLASERVILASERmAILASERVLASER1/slope=differential resistance RDLasers:5 10WILASERVLASERILASERmAITHP mWT2T3Temperature T1T2T3T1Threshold current 2025 IEEE International

31、 Solid-State Circuits Conference0.00.20.40.60.81.0012345PVCSELmWIVCSELmAAnatomy of an optical link:IMDD linksModulation properties of lasers and VCSELs9 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversVVCSELVIVCSELmAIVCSELVVCSEL1/slope=differential resistance RDVCSEL

32、s:50 100WIVCSELVVCSELT1Temperature T1T2 vTH:digital 1vRX vTH:digital 1vRX vTH:digital 1vRX vTH:digital 0Bit errors!2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksDirect detection:noise and bit-error rateAssumeaverage current for received digital 1saverage

33、 current for received digital 0svariance of noise current corresponding to digital 1svariance of noise current corresponding to digital 0s 20 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers1001 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an opt

34、ical link:IMDD linksDirect detection:noise and bit-error rateAssumeaverage current for received digital 1saverage current for received digital 0svariance of noise current corresponding to digital 1svariance of noise current corresponding to digital 0sQ-factor20 of 75Peter OssieurT6:Front-end circuit

35、 design for high-speed optical transceivers1001=1 01+0 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksDirect detection:noise and bit-error rateAssumeaverage current for received digital 1saverage current for received digital 0svariance of noise current co

36、rresponding to digital 1svariance of noise current corresponding to digital 0sQ-factorBit-error rate for NRZ signal can then be calculated from:20 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers=12erfc21001=1 01+0 2025 IEEE International Solid-State Circuits Confere

37、nceAnatomy of an optical link:IMDD linksDirect detection:noise and bit-error rateAssumeaverage current for received digital 1saverage current for received digital 0svariance of noise current corresponding to digital 1svariance of noise current corresponding to digital 0sQ-factorBit-error rate for NR

38、Z signal can then be calculated from:Under the assumption that the decision threshold was placed at:20 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers=12erfc21001=1 01+001+101+0 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD l

39、inksDirect detection:noise and bit-error rateBit-error rate for NRZ signal can then be calculated from:21 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers=12erfc21.0E-151.0E-121.0E-091.0E-061.0E-031.0E+0012345678910Bit-error rateQ-factor1.010-310-610-910-1210-15Bit-e

40、rror rate 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksDirect detection:noise and bit-error rateBit-error rate for NRZ signal can then be calculated from:21 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers=12erfc21.0E-15

41、1.0E-121.0E-091.0E-061.0E-031.0E+0012345678910Bit-error rateQ-factor1.010-310-610-910-1210-15Bit-error rateQ=3.09 for BER=10-3Q=7.03 for BER=10-12 2025 IEEE International Solid-State Circuits ConferenceSimple optical link budget:53Gb/s NRZ link22 of 755dB modulator OMA penalty6dB extinction ratioRes

42、ponsivity:0.8A/WInput-ref.noise:4.8mArmsPeter OssieurT6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceSimple optical link budget:53Gb/s NRZ link0dBm5dB modulator OMA penalty6dB extinction ratio-5dBmResponsivity:0.8A/WInput-ref.noi

43、se:4.8mArmsPeter OssieurT6:Front-end circuit design for high-speed optical transceivers22 of 75 2025 IEEE International Solid-State Circuits Conference1.0E-061.0E-051.0E-041.0E-031.0E-02-15-13-11-9-7-5Bit-error rateReceived optical power dBm,OMASimple optical link budget:53Gb/s NRZ link0dBm5dB modul

44、ator OMA penalty6dB extinction ratio-5dBmResponsivity:0.8A/WInput-ref.noise:4.8mArms-14.4dBmBER=2x10-4Can support 9.4dB lossPeter OssieurT6:Front-end circuit design for high-speed optical transceivers22 of 75 2025 IEEE International Solid-State Circuits Conference1.0E-061.0E-051.0E-041.0E-031.0E-02-

45、15-13-11-9-7-5Bit-error rateReceived optical power dBm,OMASimple optical link budget:53GBd PAM-4 link0dBm5dB modulator OMA penalty6dB extinction ratio-5dBmResponsivity:0.8A/WInput-ref.noise:4.8mArms-9.4dBmBER=2x10-45dB penaltyPeter OssieurT6:Front-end circuit design for high-speed optical transceive

46、rs22 of 75 2025 IEEE International Solid-State Circuits Conference1.0E-061.0E-051.0E-041.0E-031.0E-02-15-13-11-9-7-5Bit-error rateReceived optical power dBm,OMASimple optical link budget:53GBd PAM-4 link0dBm5dB modulator OMA penalty6dB extinction ratio-5dBmResponsivity:0.8A/WInput-ref.noise:4.8mArms

47、-9.4dBmBER=2x10-4Can support 4.4dB loss5dB penaltyPeter OssieurT6:Front-end circuit design for high-speed optical transceivers22 of 75 2025 IEEE International Solid-State Circuits Conference1.0E-061.0E-051.0E-041.0E-031.0E-02-15-13-11-9-7-5Bit-error rateReceived optical power dBm,OMASimple optical l

48、ink budget:53GBd PAM-4 link0dBm5dB modulator OMA penalty6dB extinction ratio-5dBmResponsivity:0.8A/WInput-ref.noise:4.8mArms-9.4dBmBER=2x10-4Can support 4.4dB loss5dB penaltyPeter OssieurT6:Front-end circuit design for high-speed optical transceivers22 of 75x3 eye height reductionvs.NRZ modulation 2

49、025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksRelative intensity noise of the laser23 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers =+()()Average laser optical powerRandom fluctuations of laser optical power 2025 IEEE I

50、nternational Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksRelative intensity noise of the laserUsually expressed as dBc/Hz23 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers =+()()Average laser optical powerRandom fluctuations of laser optical

51、power=10log102 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksRelative intensity noise of the laserUsually expressed as dBc/Hz23 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers =+()()Average laser optical powerRandom fluc

52、tuations of laser optical power=10log102-10.0-9.0-8.0-7.0-6.0-5.0-150-145-140-135Sensitivity dBmLaser RIN dBc/Hz53GBd PAM-4 receiver sensitivityResponsivity:0.8A/WInput-ref.noise:4.8mArmsBER=2x10-4 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksInput-refe

53、rred noise current:dealing with frequency-dependent noise densityNoise current referred back to input of optical receiver for ease of comparison:24 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers2,2Transimpedance amplifier(see later)Transimpedance dc-gainTransimpeda

54、nce frequency transferInput-referred noise current densityDetection bandwidth,2=12022 E.Sackinger,Analysis and design of transimpedance amplifiers for optical receivers,John Wiley and Sons,2018.2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:IMDD linksInput-referred

55、 noise current:dealing with frequency-dependent noise densityNoise current referred back to input of optical receiver for ease of comparison:Input-referred noise current density usually has form:Then:24 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers,2=12022 2=0+22,

56、2=02+233Bitrate22ndpersonick integral,I2=0.740 for 2ndorder Butterworth33rdpersonick integral,I3=0.329 for 2ndorder Butterworth2,2Transimpedance amplifier(see later)E.Sackinger,Analysis and design of transimpedance amplifiers for optical receivers,John Wiley and Sons,2018.2025 IEEE International Sol

57、id-State Circuits ConferenceOutlineAnatomy of an optical linkIntensity-modulated,direct-detect optical linksCoherent optical linksModulator driver circuitryLumped driver circuitsTraveling wave driver circuitsOptical receiver circuitryConclusions and upcoming research challenges25 of 75Peter OssieurT

58、6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksIncreasing spectral efficiencyTill now:intensity modulation:only amplitude of optical carrier modulated26 of 75Peter OssieurT6:Front-end circ

59、uit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksIncreasing spectral efficiencyTill now:intensity modulation:only amplitude of optical carrier modulatedAlternative to non-return to zero modulation:binary ph

60、ase shift keying(BPSK)26 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversP.J.Winzer and R.-J.Essiambre,Advanced Optical Modulation Formats,in Proceedings of the IEEE,vol.94,no.5,pp.952-985,May 2006 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an

61、optical link:coherent linksIncreasing spectral efficiencyTill now:intensity modulation:only amplitude of optical carrier modulatedIQ phase modulation of the optical carrier allows to increase capacity using e.g.QPSK(quadrature phase-shift keying),16-QAM(16-ary quadrature modulation)Frequency of a 13

62、10nm(O-band)optical carrier:228.8THz26 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversP.J.Winzer and R.-J.Essiambre,Advanced Optical Modulation Formats,in Proceedings of the IEEE,vol.94,no.5,pp.952-985,May 2006 2025 IEEE International Solid-State Circuits Conference

63、Anatomy of an optical link:coherent linksIncreasing spectral efficiencyTill now:intensity modulation:only amplitude of optical carrier modulatedIQ phase modulation of the optical carrier allows to increase capacity using e.g.QPSK(quadrature phase-shift keying),16-QAM(16-ary quadrature modulation)Fre

64、quency of a 1310nm(O-band)optical carrier:228.8THzIQ modulation of the two orthogonal(TE and TM)polarizations:double spectral efficiencyTE:transverse electric polarization modeTM:transverse magnetic polarization mode26 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers

65、P.J.Winzer and R.-J.Essiambre,Advanced Optical Modulation Formats,in Proceedings of the IEEE,vol.94,no.5,pp.952-985,May 2006 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can we generate such dual-polarization,IQ modulated signals?Mach-Zehnder mo

66、dulator27 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversECW,in+Vdr/2-Vdr/2+22EOUT-1.0-0.50.00.51.0-2-1012Normalized power or field magnitudeNormalized drive voltage Power transferIntensity modulation:quadrature biasVp 2025 IEEE International Solid-State Circuits Co

67、nferenceAnatomy of an optical link:coherent linksHow can we generate such dual-polarization,IQ modulated signals?Mach-Zehnder modulator27 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversECW,in+Vdr/2-Vdr/2+22EOUT-1.0-0.50.00.51.0-2-1012Normalized power or field magnit

68、udeNormalized drive voltage Power transferField transferPhase modulation:min.transmission point2Vp 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can we generate such dual-polarization,IQ modulated signals?Mach-Zehnder modulator27 of 75Peter Ossie

69、urT6:Front-end circuit design for high-speed optical transceiversECW,in+Vdr/2-Vdr/2+22EOUT-1.0-0.50.00.51.0-2-1012Normalized power or field magnitudeNormalized drive voltage Power transferField transferPhase modulation:min.transmission point2Vp 2025 IEEE International Solid-State Circuits Conference

70、Anatomy of an optical link:coherent linksDual-polarization,IQ modulator28 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversppTETM 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksDual-polarization,IQ modulator28 of 75Pete

71、r OssieurT6:Front-end circuit design for high-speed optical transceiversppTETM 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksDual-polarization,IQ modulator28 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversppTETM 2025

72、 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksDual-polarization,IQ modulator28 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversppTETMTETM 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:c

73、oherent linksHow can we detect such signals?Enter the coherent optical receiver!29 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers=2cos +2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can we detect such signals?En

74、ter the coherent optical receiver!29 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers=2cos +=2cos +K.Kikuchi,Fundamentals of Coherent Optical Fiber Communications,in Journal of Lightwave Technology,2016 2025 IEEE International Solid-State Circuits ConferenceAnatomy o

75、f an optical link:coherent linksHow can we detect such signals?Enter the coherent optical receiver!29 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers3dB coupler=2cos +=2cos +=2 cos +K.Kikuchi,Fundamentals of Coherent Optical Fiber Communications,in Journal of Lightw

76、ave Technology,2016 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can we detect such signals?Enter the coherent optical receiver!29 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers3dB coupler=2cos +=2cos +Amplific

77、ation due to mixing with local oscillator laser,leading to improved receiver sensitivity =2 cos +K.Kikuchi,Fundamentals of Coherent Optical Fiber Communications,in Journal of Lightwave Technology,2016 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow

78、 can we detect such signals?Polarization and phase diversity coherent Rx30 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can we detect such signals?Polarization and

79、 phase diversity coherent Rx30 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers90 degree hybrid90 degree hybridIXQXIYQY 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can we detect such signals?Polarization and pha

80、se diversity coherent Rx30 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers90 degree hybrid90 degree hybridIXQXIYQYADCADCADCADCDeskew and IQ imbalance compensation 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can

81、 we detect such signals?Polarization and phase diversity coherent Rx30 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers90 degree hybrid90 degree hybridIXQXIYQYADCADCADCADCDeskew and IQ imbalance compensationChromatic dispersion compensation 2025 IEEE International So

82、lid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can we detect such signals?Polarization and phase diversity coherent Rx30 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers90 degree hybrid90 degree hybridIXQXIYQYADCADCADCADCDeskew and IQ imbal

83、ance compensationChromatic dispersion compensationTiming recovery 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can we detect such signals?Polarization and phase diversity coherent Rx30 of 75Peter OssieurT6:Front-end circuit design for high-speed

84、 optical transceivers90 degree hybrid90 degree hybridIXQXIYQYADCADCADCADCDeskew and IQ imbalance compensationChromatic dispersion compensationTiming recoveryPolarization demultiplexing 2025 IEEE International Solid-State Circuits ConferenceAnatomy of an optical link:coherent linksHow can we detect s

85、uch signals?Polarization and phase diversity coherent Rx30 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers90 degree hybrid90 degree hybridIXQXIYQYADCADCADCADCDeskew and IQ imbalance compensationChromatic dispersion compensationTiming recoveryPolarization demultiplex

86、ingFrequency and phase recovery 2025 IEEE International Solid-State Circuits ConferenceOutlineAnatomy of an optical linkIntensity-modulated,direct-detect optical linksCoherent optical linksModulator driver circuitryLumped driver circuitsTraveling wave driver circuitsOptical receiver circuitryConclus

87、ions and upcoming research challenges31 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceLaser,VCSEL and modulator driver circuitry32 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiv

88、ersSpecificationRemarkNumber of channels1,4,8,Output bias current mALasers or VCSELs,usually tunable,few mA to 10s of mAOutput modulation current mAppLasers or VCSELs,usually tunable,few mA to 10s of mAOutput bias voltage VUsually tunable,0V to several VOuput modulation voltage VppSingle-ended or di

89、fferential,can be tunable,15VBaudrate GBde.g.56Gb/s NRZ,112GBd PAM-4,250GBd 16-QAMRise-and fall times ps0.1 to 0.25 x symbol period,e.g.5ps for 53Gb/s NRZ3dB bandwidth GHz Nyquist bandwidth,e.g.56GHz for 112GBd PAM-4Peaking dBCan be tunable,equalize high-frequency lossesGroup delay variation ps0.25

90、x symbol period up till Nyquist frequencyTotal harmonic distortion%For linear drivers,e.g.2%with 1GHz toneInput-and output return loss dBE.g.10V!Discharging of Ccdue to IPHincreases baseline wander 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers39 of 75Peter Oss

91、ieurT6:Front-end circuit design for high-speed optical transceiversDifferential EAM and ring modulator drivers:current steering approachSimultaneous application of DC-bias and high-speed signals:through power railsSmall bias currents IBAand IBCallow tuning duty cycle and balance diff.pairH.Ramon et

92、al.,70 Gb/s Low-Power DC-Coupled NRZ Differential Electro-Absorption Modulator Driver in 55 nm SiGe BiCMOS,in Journal of Lightwave Technology,vol.37,no.5,pp.1504-1514,March 2019VIN+VIN-IPHVBIAS,AVBIAS,CIPHIPHIBCIBA 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers

93、39 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversDifferential EAM and ring modulator drivers:bandwidth enhancement techniquesShunt inductive peakingCross-coupled capacitors partially cancelling capacitive loading of amplifierH.Ramon et al.,70 Gb/s Low-Power DC-Coup

94、led NRZ Differential Electro-Absorption Modulator Driver in 55 nm SiGe BiCMOS,in Journal of Lightwave Technology,vol.37,no.5,pp.1504-1514,March 2019VIN+VIN-IPH 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers40 of 75Peter OssieurT6:Front-end circuit design for hi

95、gh-speed optical transceiversCommon-source NMOS driverVINVOUT 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers40 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCommon-source NMOS driverVINVOUTAchievable voltage swing limited by d

96、rain-source and drain-gate breakdown voltage 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers40 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCommon-source,cascoded NMOS driverVINVOUTAchievable voltage swing limited by drain to

97、gate breakdown of cascode transistor.One solution:use a thick-oxide transistor for the cascode device:due to common-gate arrangement,the speed of the cascode transistor is less criticalVBIAS 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers40 of 75Peter OssieurT6:

98、Front-end circuit design for high-speed optical transceiversCommon-source,stacked NMOS driverStack three transistors M1,M2,M3VOUTVINVBIASM1M2M3T.-J.Chen,et.al.,A 64-Gb/s 4.2-Vpp Modulator Driver Using Stacked-FET Distributed Amplifier Topology in 65-nm CMOS,2019 IEEE MTT-S International Microwave Sy

99、mposium(IMS),2019J.Kim and J.F.Buckwalter,A 40-Gb/s Optical Transceiver Front-End in 45 nm SOI CMOS,in IEEE Journal of Solid-State Circuits,vol.47,no.3,pp.615-626,March 2012 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers40 of 75Peter OssieurT6:Front-end circuit

100、 design for high-speed optical transceiversCommon-source,stacked NMOS driverStack three transistors M1,M2,M3Gates of M2and M3dynamically biased using capacitively loaded resistive dividerFurther reduces the gate drain voltage stress on transistor M3VOUTVINVBIASM1M2M3C2C3T.-J.Chen,et.al.,A 64-Gb/s 4.

101、2-Vpp Modulator Driver Using Stacked-FET Distributed Amplifier Topology in 65-nm CMOS,2019 IEEE MTT-S International Microwave Symposium(IMS),2019J.Kim and J.F.Buckwalter,A 40-Gb/s Optical Transceiver Front-End in 45 nm SOI CMOS,in IEEE Journal of Solid-State Circuits,vol.47,no.3,pp.615-626,March 201

102、2 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers40 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCommon-source,stacked NMOS driverStack three transistors M1,M2,M3Gates of M2and M3dynamically biased using capacitively loaded re

103、sistive dividerFurther reduces the gate drain voltage stress on transistor M3VOUTVINVBIASThe gate-source capacitors form a capacitivedividers with C2and C3,setting the dynamicbias at the gates of M2and M3M1M2M3C2C3T.-J.Chen,et.al.,A 64-Gb/s 4.2-Vpp Modulator Driver Using Stacked-FET Distributed Ampl

104、ifier Topology in 65-nm CMOS,2019 IEEE MTT-S International Microwave Symposium(IMS),2019J.Kim and J.F.Buckwalter,A 40-Gb/s Optical Transceiver Front-End in 45 nm SOI CMOS,in IEEE Journal of Solid-State Circuits,vol.47,no.3,pp.615-626,March 2012 2025 IEEE International Solid-State Circuits Conference

105、EAM and ring modulator drivers41 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCMOS inverter style ring modulator drivers:easy interface with digital logicMaximum achievable swing limited by supply voltage 0.8V 1.0VSignificant improved optical modulation amplitude

106、for drive swing 2.0VHow can we achieve such swings?-25.0-20.0-15.0-10.0-5.00.01307.501307.751308.001308.251308.50Modulator OMA penalty dBWavelength nmVoltage swing=2VVoltage swing=1V2.7dB 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers42 of 75Peter OssieurT6:Fro

107、nt-end circuit design for high-speed optical transceiversCMOS inverter style ring modulator drivers:easy interface with digital logicHow can we achieve such swings?Negative supply railMaximum voltage stress VDD,take care during transitionsVDDGND-VDDVINVIN-VDDVDD2xVDDJ.F.Buckwalter,X.Zheng,G.Li,K.Raj

108、 and A.V.Krishnamoorthy,A Monolithic 25-Gb/s Transceiver With Photonic Ring Modulators and Ge Detectors in a 130-nm CMOS SOI Process,in IEEE Journal of Solid-State Circuits,vol.47,no.6,pp.1309-1322,June 2012 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers42 of 7

109、5Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCMOS inverter style ring modulator drivers:easy interface with digital logicHow can we achieve such swings?Static biased cascode voltage doubler Use VDDand 2x VDDsupply railsGNDVIN+VDDVINVDDVDD2x VDDVDD2x VDDGNDVDDS.Palermo

110、 and M.Horowitz,High-Speed Transmitters in 90nm CMOS for High-Density Optical Interconnects,“ESSCIRC 2006.S.Zhou et.al.,“Driver circuit for a PAM-4 optical transmitter using 65nm CMOS and silicon photonic technologies”,Electronics Letters,vol.52,Nov.2016 2025 IEEE International Solid-State Circuits

111、ConferenceEAM and ring modulator drivers42 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCMOS inverter style ring modulator drivers:easy interface with digital logicHow can we achieve such swings?Static biased cascode voltage doublerUse VDDand 2x VDDsupply rails:ma

112、x.voltage stress VDDGNDVIN+VDDVINVDDVDD2x VDDVDDVDDVDD2x VDDGNDVDDGND2x VDD 2025 IEEE International Solid-State Circuits ConferenceEAM and ring modulator drivers42 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversCMOS inverter style ring modulator drivers:easy interfa

113、ce with digital logicHow can we achieve such swings?Static biased cascode voltage doublerUse VDDand 2x VDDsupply rails:max.voltage stress 70Output swing Vpp,diff3.41dB output compression dBm15.2 1GHzTHD%,1GHz tone2%3.56VPPPower mW/channel725 2025 IEEE International Solid-State Circuits ConferenceTra

114、veling-wave modulator driversSiGe BiCMOS HBT based traveling-wave modulator driverTunable gain to support wide range of input voltagesPeaking at Nyquist(55GHz)to enhance optical transmitter EOE(electro-optical to electrical)bandwidthPeter Ossieur52 of 75T6:Front-end circuit design for high-speed opt

115、ical transceiversS.Niu et al.,A Linear Modulator Driver With Over 70-GHz Bandwidth 21.8-dB Gain and 3.4-Vppd Output Swing for Beyond 120-GBd Optical Links,IEEE Transactions on Microwave Theory and Techniques,July 2024 2025 IEEE International Solid-State Circuits ConferenceTraveling-wave modulator dr

116、iversSiGe BiCMOS HBT based traveling-wave modulator driverLinearity is critical for PAM-4 and coherent transmitter applicationsTotal harmonic distortion:Peter Ossieur53 of 75T6:Front-end circuit design for high-speed optical transceivers=22+32+42+52+62+1Typical spec1:amplitude of fundamental tone:am

117、plitude of mthharmonic tone 2025 IEEE International Solid-State Circuits ConferenceTraveling-wave modulator driversSiGe BiCMOS HBT based traveling-wave modulator driverPeter Ossieur54 of 75T6:Front-end circuit design for high-speed optical transceiversS.Niu et al.,A Linear Modulator Driver With Over

118、 70-GHz Bandwidth 21.8-dB Gain and 3.4-Vppd Output Swing for Beyond 120-GBd Optical Links,IEEE Transactions on Microwave Theory and Techniques,July 2024B2B:waveform generator to scopeThru:calibration substrate 2025 IEEE International Solid-State Circuits ConferenceOutlineAnatomy of an optical linkIn

119、tensity-modulated,direct-detect optical linksCoherent optical linksModulator driver circuitryLumped driver circuitsTraveling-wave driver circuitsOptical receiver circuitryConclusions and upcoming research challenges55 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceivers

120、2025 IEEE International Solid-State Circuits ConferenceOptical receiver specifications56 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversSpecificationRemarkNumber of channels1,4,8,Min.AC input current mAppDefined by required SNR(Q-factor),few mAMax.AC input current m

121、AppSeveral mAppDC input current mA0 to several mA(e.g.coherent receivers)Input-referred noise current mArmsDepends on bandwidth,100nArmstill few mArmsOutput voltage swing mV100mV 500mV 1VBaudrate GBd112Gb/s NRZ,112GBd PAM-4,250GBd 16-QAM3dB bandwidth GHzFor example Nyquist bandwidthPeaking dBCan be

122、tunable,equalize high-frequency lossesGroup delay variation psE.g.0.25 x symbol period up till Nyquist frequencyTotal harmonic distortion%Usually measured with 1GHz tone,see laterInput-and output return loss dBE.g.-10dB till Nyquist 2025 IEEE International Solid-State Circuits ConferenceRecap of our

123、 optical link5dB modulator OMA penalty6dB extinction ratioResponsivity:0.8A/W-9.4dBmPeter OssieurT6:Front-end circuit design for high-speed optical transceivers57 of 75Design optical receiver with following specifications:1)3dB bandwidth 40GHz2)Input-referred noise current 500mVPP 2025 IEEE Internat

124、ional Solid-State Circuits ConferenceRecap of our optical link5dB modulator OMA penalty6dB extinction ratioResponsivity:0.8A/W-9.4dBmPeter OssieurT6:Front-end circuit design for high-speed optical transceivers57 of 75Design optical receiver with following specifications:1)3dB bandwidth 40GHz2)Input-

125、referred noise current 500mVPPI1=69mAI0=17mAI1-I0=52mA 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalThe high-impedance front-endPeter Ossieur58 of 75=5001 0=9.7Optical receiver specifications:1)3dB bandwidth 40GHz2)Input-referred noise current 500m

126、VPPT6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalThe high-impedance front-endPeter Ossieur58 of 75=753=12=219=5001 0=9.7Photodetector capacitance,pad capacitance,ESD protection diodes,i

127、nput capacitance subsequent receiver stages and interconnectOptical receiver specifications:1)3dB bandwidth 40GHz2)Input-referred noise current 500mVPPT6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an op

128、tical signalThe low-impedance front-endPeter Ossieur59 of 75=123=53.1=75Optical receiver specifications:1)3dB bandwidth 40GHz2)Input-referred noise current 500mVPPT6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceDetecting and ampl

129、ifying an optical signalThe low-impedance front-endPeter Ossieur59 of 75=123=53.1=75,=1=4.7Optical receiver specifications:1)3dB bandwidth 40GHz2)Input-referred noise current 500mVPPT6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits Conferenc

130、eDetecting and amplifying an optical signalThe transimpedance amplifier front-endThe feedback action improves achievable gain x bandwidth by a factor equal to gain of the voltage amplifierFor example,assume A=10Peter Ossieur60 of 75=+111+2+1=75=+1 11+2Optical receiver specifications:1)3dB bandwidth

131、40GHz2)Input-referred noise current 500mVPP=10+123=584,=1=424T6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalThe transimpedance amplifier front-endThe feedback action improves achievable

132、gain x bandwidth by a factor equal to gain of the voltage amplifierFor example,assume A=10.Remaining 24.4dB through additional stagesPeter Ossieur60 of 75=+111+2+1=75=+1 11+2=10+123=584,=1=424Optical receiver specifications:1)3dB bandwidth 40GHz2)Input-referred noise current 500mVPPT6:Front-end circ

133、uit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalThe transimpedance amplifier front-endThe feedback action improves achievable gain x bandwidth by a factor equal to gain of the voltage amplifierFor example

134、,assume A=10.Remaining 24.4dB through additional stagesPeter Ossieur60 of 75=+111+2+1=75=+1 11+2=10+123=584,=1=424Optical receiver specifications:1)3dB bandwidth 40GHz2)Input-referred noise current 500mVPPVoltage amplifier will now add noise!T6:Front-end circuit design for high-speed optical transce

135、ivers 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalThe transimpedance amplifier:voltage-amplifier A with finite bandwidth:Second-order transfer function(A 1):Peter Ossieur61 of 75T6:Front-end circuit design for high-speed optical transceivers()=01+

136、11+20+242020=12=+with:=12E.Sackinger,Analysis and design of transimpedance amplifiers for optical receivers,John Wiley&Sons,2018 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalThe transimpedance amplifier:Bessel-Thomson responseSecond-order transfer

137、function(A 1):Transimpedance amplifiers for multilevel modulation formats(PAM-4)Preferably no peaking in the amplitude response and flat group delayPoints to:Bessel-Thomson filter response,for which:Hence bandwidth fAof voltage-amplifier:3dB bandwidth for Bessel-Thomson response:Peter Ossieur62 of 7

138、5T6:Front-end circuit design for high-speed optical transceivers 11+20+242020=12=+with:=13=32E.Sackinger,Analysis and design of transimpedance amplifiers for optical receivers,John Wiley&Sons,20183=0.7860 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical sign

139、alThe transimpedance amplifier:Bessel-Thomson responseTransimpedance amplifiers for multilevel modulation formats(PAM-4)Preferably no peaking in the amplitude response and flat group delayPoints to:Bessel-Thomson filter response,for which:Hence bandwidth fAof voltage-amplifier:3dB bandwidth for Bess

140、el-Thomson response:Peter Ossieur62 of 75T6:Front-end circuit design for high-speed optical transceivers=13=32E.Sackinger,Analysis and design of transimpedance amplifiers for optical receivers,John Wiley&Sons,20183=0.7860=1.362 2Remarkable!2025 IEEE International Solid-State Circuits ConferenceDetec

141、ting and amplifying an optical signalThe common-emitter transimpedance amplifierInput dc-bias voltage=1x VBEEmitter follower Q2increases the collector-emitter voltage across Q1,increasing its fTVBIASneeds to be carefully decoupled:any disturbance is coupled to the TIA input via the photodetectors ca

142、pacitance and amplifiedPeter Ossieur63 of 75T6:Front-end circuit design for high-speed optical transceiversQ1IBIASvOUTRCRFVCCVCCVBIASQ2 2025 IEEE International Solid-State Circuits Conference0.11.010.0100.00.1110100Input-referred noise current density pA/Hz1/2Frequency GHzDetecting and amplifying an

143、 optical signalThe common-emitter transimpedance amplifierInput-referred noise current densityPeter Ossieur63 of 75T6:Front-end circuit design for high-speed optical transceiversQ1IBIASvOUTRCRFVCCVCCVBIASQ22=4+2+22+222+4222Noise due to feedback resistorRF=380W,Rb=10W b=250,fT=250GHz,Ic=5mA,gm=170mS,

144、Cp=111fF,CTOT=75fFE.Sackinger,Analysis and design of transimpedance amplifiers for optical receivers,John Wiley&Sons,2018 2025 IEEE International Solid-State Circuits Conference0.11.010.0100.00.1110100Input-referred noise current density pA/Hz1/2Frequency GHzDetecting and amplifying an optical signa

145、lThe common-emitter transimpedance amplifierInput-referred noise current densityPeter Ossieur63 of 75T6:Front-end circuit design for high-speed optical transceiversQ1IBIASvOUTRCRFVCCVCCVBIASQ22=4+2+22+222+4222Noise due to base current shot noiseRF=380W,Rb=10W b=250,fT=250GHz,Ic=5mA,gm=170mS,Cp=111fF

146、,CTOT=75fF 2025 IEEE International Solid-State Circuits Conference0.11.010.0100.00.1110100Input-referred noise current density pA/Hz1/2Frequency GHzDetecting and amplifying an optical signalThe common-emitter transimpedance amplifierInput-referred noise current densityPeter Ossieur63 of 75T6:Front-e

147、nd circuit design for high-speed optical transceiversQ1IBIASvOUTRCRFVCCVCCVBIASQ22=4+2+22+222+4222Noise due to collector current shot noiseRF=380W,Rb=10W b=250,fT=250GHz,Ic=5mA,gm=170mS,Cp=111fF,CTOT=75fF 2025 IEEE International Solid-State Circuits Conference0.11.010.0100.00.1110100Input-referred n

148、oise current density pA/Hz1/2Frequency GHzDetecting and amplifying an optical signalThe common-emitter transimpedance amplifierInput-referred noise current densityPeter Ossieur63 of 75T6:Front-end circuit design for high-speed optical transceiversQ1IBIASvOUTRCRFVCCVCCVBIASQ22=4+2+22+222+4222Noise du

149、e to base resistanceRF=380W,Rb=10W b=250,fT=250GHz,Ic=5mA,gm=170mS,Cp=111fF,CTOT=75fF 2025 IEEE International Solid-State Circuits Conference0.11.010.0100.00.1110100Input-referred noise current density pA/Hz1/2Frequency GHzDetecting and amplifying an optical signalThe common-emitter transimpedance a

150、mplifierInput-referred noise current densityPeter Ossieur63 of 75T6:Front-end circuit design for high-speed optical transceiversQ1IBIASvOUTRCRFVCCVCCVBIASQ22=4+2+22+222+4222Noise starts to rise well before TIA 3-dB bandwidth:typical bump in output-referred noise current densityRF=380W,Rb=10W b=250,f

151、T=250GHz,Ic=5mA,gm=170mS,Cp=111fF,CTOT=75fF 2025 IEEE International Solid-State Circuits Conference01101000.1110100Input-referred noise current density pA/Hz1/2Frequency GHzDetecting and amplifying an optical signalThe common-source transimpedance amplifierInput-referred noise current densityPeter O

152、ssieur64 of 75T6:Front-end circuit design for high-speed optical transceiversM1vOUTRDRFVCCVBIAS2=4+2+42+42+22Noise due to feedback resistorRF=380W,IG=100nAG=3,fT=310GHz,gm=100mS,CGS+CGD=51fF,CTOT=75fF 2025 IEEE International Solid-State Circuits Conference01101000.1110100Input-referred noise current

153、 density pA/Hz1/2Frequency GHzDetecting and amplifying an optical signalThe common-source transimpedance amplifierInput-referred noise current densityPeter Ossieur64 of 75T6:Front-end circuit design for high-speed optical transceiversM1vOUTRDRFVCCVBIAS2=4+2+42+42+22Shot noise due to gate leakage cur

154、rentRF=380W,IG=100nAG=3,fT=310GHz,gm=100mS,CGS+CGD=51fF,CTOT=75fF 2025 IEEE International Solid-State Circuits Conference01101000.1110100Input-referred noise current density pA/Hz1/2Frequency GHzDetecting and amplifying an optical signalThe common-source transimpedance amplifierInput-referred noise

155、current densityPeter Ossieur64 of 75T6:Front-end circuit design for high-speed optical transceiversM1vOUTRDRFVCCVBIAS2=4+2+42+42+22NMOS channel noiseRF=380W,IG=100nAG=3,fT=310GHz,gm=100mS,CGS+CGD=51fF,CTOT=75fF 2025 IEEE International Solid-State Circuits Conference01101000.1110100Input-referred noi

156、se current density pA/Hz1/2Frequency GHzDetecting and amplifying an optical signalThe common-source transimpedance amplifierInput-referred noise current densityPeter Ossieur64 of 75T6:Front-end circuit design for high-speed optical transceiversM1vOUTRDRFVCCVBIAS2=4+2+42+42+22NMOS channel noiseRF=380

157、W,IG=100nAG=3,fT=310GHz,gm=100mS,CGS+CGD=51fF,CTOT=75fF 2025 IEEE International Solid-State Circuits Conference01101000.1110100Input-referred noise current density pA/Hz1/2Frequency GHzDetecting and amplifying an optical signalThe common-source transimpedance amplifierInput-referred noise current de

158、nsityPeter Ossieur64 of 75T6:Front-end circuit design for high-speed optical transceiversM1vOUTRDRFVCCVBIAS2=4+2+42+42+22RF=380W,IG=100nAG=3,fT=310GHz,gm=100mS,CGS+CGD=51fF,CTOT=75fFNoise starts to rise well before TIA 3-dB bandwidth:typical bump in output-referred noise current density 2025 IEEE In

159、ternational Solid-State Circuits ConferenceDetecting and amplifying an optical signalA differential common-emitter transimpedance amplifierConventional transimpedance amplifier:single-ended operationCurrent from one end of the photodiode is amplifiedSingle-ended to differential conversion after the

160、front-endPeter Ossieur65 of 75T6:Front-end circuit design for high-speed optical transceivers()+,J.Lambrecht et al.,90-Gb/s NRZ Optical Receiver in Silicon Using a Fully Differential Transimpedance Amplifier,Journal of Lightwave Technology,May 2019 2025 IEEE International Solid-State Circuits Confer

161、enceDetecting and amplifying an optical signalA differential common-emitter transimpedance amplifierSense from cathode and anode side:In principle 1.5dB optical sensitivity improvement(assuming uncorrelated noise)Improved immunity against power supply noise and crosstalkPeter Ossieur65 of 75T6:Front

162、-end circuit design for high-speed optical transceivers()+,J.Lambrecht et al.,90-Gb/s NRZ Optical Receiver in Silicon Using a Fully Differential Transimpedance Amplifier,Journal of Lightwave Technology,May 2019+2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optica

163、l signalA differential common-emitter transimpedance amplifierSense from cathode and anode side:Equivalent circuits single-ended vs.differential detectionPeter Ossieur65 of 75T6:Front-end circuit design for high-speed optical transceiversJ.Lambrecht et al.,90-Gb/s NRZ Optical Receiver in Silicon Usi

164、ng a Fully Differential Transimpedance Amplifier,Journal of Lightwave Technology,May 2019RPD/2CPDRPD/2IPDLBWLBWVBIASPhotodiodeSingle-ended TIA 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalA differential common-emitter transimpedance amplifierSense

165、from cathode and anode side:Equivalent circuits single-ended vs.differential detectionPeter Ossieur65 of 75T6:Front-end circuit design for high-speed optical transceiversJ.Lambrecht et al.,90-Gb/s NRZ Optical Receiver in Silicon Using a Fully Differential Transimpedance Amplifier,Journal of Lightwav

166、e Technology,May 2019RPD/2CPDRPD/2IPDLBWLBWRPD/22xCPDRPD/2IPDLBWLBWPhotodiode2xCPDVBIASPhotodiodeSingle-ended TIADifferential TIA 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalA differential common-emitter transimpedance amplifierSense from cathode

167、and anode side:Equivalent circuits single-ended vs.differential detectionPeter Ossieur65 of 75T6:Front-end circuit design for high-speed optical transceiversJ.Lambrecht et al.,90-Gb/s NRZ Optical Receiver in Silicon Using a Fully Differential Transimpedance Amplifier,Journal of Lightwave Technology,

168、May 2019RPD/2CPDRPD/2IPDLBWLBWRPD/22xCPDRPD/2IPDLBWLBW2xCPDSingle-ended circuit:1x CPD,1x RPD,2x LBWDifferential half-circuit:2x CPD,x RPD,1x LBWPhotodiodeVBIASPhotodiodeSingle-ended TIADifferential TIA 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signal

169、A differential common-emitter transimpedance amplifierHow to apply the bias voltage to the photodetector?Peter Ossieur66 of 75T6:Front-end circuit design for high-speed optical transceiversTo TIACathode and anode forced to VrefCand VrefAusing feedback loopsJ.Lambrecht et al.,90-Gb/s NRZ Optical Rece

170、iver in Silicon Using a Fully Differential Transimpedance Amplifier,Journal of Lightwave Technology,May 2019 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalA differential common-emitter transimpedance amplifierHow to apply the bias voltage to the pho

171、todetector?Peter Ossieur66 of 75T6:Front-end circuit design for high-speed optical transceiversTo TIACathode and anode forced to VrefCand VrefAusing feedback loopsNoise contribution from drain currents of M1and M2scales with photodiode current:negligible impact on total receiver noiseMinimum current

172、 to keep loops operational set with Rh=15kWJ.Lambrecht et al.,90-Gb/s NRZ Optical Receiver in Silicon Using a Fully Differential Transimpedance Amplifier,Journal of Lightwave Technology,May 2019 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalA differ

173、ential common-emitter transimpedance amplifierHow to apply the bias voltage to the photodetector?Peter Ossieur66 of 75T6:Front-end circuit design for high-speed optical transceiversTo TIACathode and anode forced to VrefCand VrefAusing feedback loopsNoise contribution from drain currents of M1and M2s

174、cales with photodiode current:negligible impact on total receiver noiseMinimum current to keep loops operational set with Rh=15kWCoupling capacitors and loop bandwidth to be carefully designed to maintain voltage during long sequences of consecutive identical digits 2025 IEEE International Solid-Sta

175、te Circuits ConferenceDetecting and amplifying an optical signalA differential common-emitter transimpedance amplifierHow to apply the bias voltage to the photodetector?Peter Ossieur65 of 75T6:Front-end circuit design for high-speed optical transceiversTunable feedback resistor RF to handle high inp

176、ut currentsMaintain frequency response(avoid peaking or even instability):also tail current and RC2made tunableJ.Lambrecht et al.,90-Gb/s NRZ Optical Receiver in Silicon Using a Fully Differential Transimpedance Amplifier,Journal of Lightwave Technology,May 2019 2025 IEEE International Solid-State C

177、ircuits ConferenceDetecting and amplifying an optical signalA differential common-emitter transimpedance amplifierHow to apply the bias voltage to the photodetector?Peter Ossieur65 of 75T6:Front-end circuit design for high-speed optical transceivers 2025 IEEE International Solid-State Circuits Confe

178、renceDetecting and amplifying an optical signalAlternative means to lower impedance viewed from the photodiode:The common-gate transimpedance amplifierPeter Ossieur66 of 75T6:Front-end circuit design for high-speed optical transceiversVBIASVDDVGvOUTRIN1+1 Transimpedance gain:Impedance at the PD:RBRL

179、 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalAlternative means to lower impedance viewed from the photodiode:The common-gate transimpedance amplifierPeter Ossieur66 of 75T6:Front-end circuit design for high-speed optical transceiversVBIASVDDVGvOUT

180、RLInput-referred noise current density:Two resistors directly contributing to noise!2=4+4+2+42+222RB 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalAlternative means to lower impedance viewed from the photodiode:The regulated cascode transimpedance a

181、mplifier:drive the gate of the common-gate transistor with a feedback loopPeter Ossieur67 of 75T6:Front-end circuit design for high-speed optical transceiversVBIASVDDvOUTRLRB1RB2VDD111+2 Transimpedance gain:Impedance at the PD:MBM1Sung Min Park and Hoi-Jun Yoo,1.25-Gb/s regulated cascodeCMOS transim

182、pedance amplifier for Gigabit Ethernet applications,in IEEE Journal of Solid-State Circuits,an.2004 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalInverter based transimpedance amplifiers:Self-biased through feedback resistor RFTotal transconductance

183、 gMN+gMPPeter Ossieur68 of 75T6:Front-end circuit design for high-speed optical transceiversvOUTVINVOUTRFSelf-biasing throughresistorMPMNVBIAS 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalInverter based transimpedance amplifiers:Self-biased through

184、 feedback resistor RFAlternating transimpedance and transconductance stages:broadband amplification,while retaining self-biasingPeter Ossieur68 of 75T6:Front-end circuit design for high-speed optical transceiversRFvOUTH.Ramon et al.,Low-Power 56Gb/s NRZ Microring Modulator Driver in 28nm FDSOI CMOS,

185、in IEEE Photonics Technology Letters,March 2018.VBIAS 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalInverter based transimpedance amplifiers:Self-biased through feedback resistor RFAlternating transimpedance and transconductance stages:broadband amp

186、lification,while retaining self-biasingCommon-mode feedback to keep balance in presence of unipolar input and unavoidable offsetsPeter Ossieur68 of 75T6:Front-end circuit design for high-speed optical transceiversVBIASRFvOUTH.Ramon et al.,Low-Power 56Gb/s NRZ Microring Modulator Driver in 28nm FDSOI

187、 CMOS,in IEEE Photonics Technology Letters,March 2018.+VREF 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalInverter based transimpedance amplifiers:Series inductive peaking Peter Ossieur69 of 75T6:Front-end circuit design for high-speed optical trans

188、ceiversvOUTRFLsChia-Hsin Wu,Chih-Hun Lee,Wei-Sheng Chen and Shen-Iuan Liu,CMOS wideband amplifiers using multiple inductive-series peaking technique,IEEE Journal of Solid-State Circuits,Feb.2005 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalInverter

189、 based transimpedance amplifiers:Series inductive peaking Shunt inductive peakingPeter Ossieur69 of 75T6:Front-end circuit design for high-speed optical transceiversvOUTRFLsvOUTRFLsLsChia-Hsin Wu,Chih-Hun Lee,Wei-Sheng Chen and Shen-Iuan Liu,CMOS wideband amplifiers using multiple inductive-series p

190、eaking technique,IEEE Journal of Solid-State Circuits,Feb.2005S.Shopov and S.P.Voinigescu,A 360Gb/s Transmitter/Repeater Front-End With 4.3VPP Single-Ended Output Swing in a 28nm UTBB FD-SOI Technology,in IEEE Journal of Solid-State Circuits,July 2016 2025 IEEE International Solid-State Circuits Con

191、ferenceDetecting and amplifying an optical signalInverter based transimpedance amplifiers:Allow to achieve both low-power and high-speed optical receiver designsExample using 22nm FinFET CMOS:45.5GHz bandwidth,920W transimpedance gain12.6pA/Hz1/2input-referred noise densityDemonstrated up to 64Gbaud

192、 PAM-4DC-power:11.2mWPeter Ossieur69 of 75T6:Front-end circuit design for high-speed optical transceiversS.Daneshgar,H.Li,T.Kim and G.Balamurugan,A 128 Gb/s,11.2 mW Single-Ended PAM4 Linear TIA With 2.7 Arms Input Noise in 22 nm FinFET CMOS,in IEEE Journal of Solid-State Circuits,May 2022 2025 IEEE

193、International Solid-State Circuits ConferenceDetecting and amplifying an optical signal T-coil based bandwidth broadeningPeter Ossieur70 of 75T6:Front-end circuit design for high-speed optical transceiversVOUTVINRDCLB.Razavi,“The bridged T-coil:a circuit for all seasons”,IEEE Solid-state circuits ma

194、gazine,2015.2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalPeter Ossieur70 of 75T6:Front-end circuit design for high-speed optical transceiversVOUTVINRDCLL1VOUTVINCLRDL2CBB.Razavi,“The bridged T-coil:a circuit for all seasons”,IEEE Solid-state circui

195、ts magazine,2015.T-coil based bandwidth broadening 2025 IEEE International Solid-State Circuits ConferenceDetecting and amplifying an optical signalPeter Ossieur70 of 75T6:Front-end circuit design for high-speed optical transceiversVOUTVINRDCLL1VOUTVINCLRDL2CB=22+2+22ndorder transfer function:Assume

196、 we want certain dampingfactor :1=2=241+142Coupling factor=42 142+1=162B.Razavi,“The bridged T-coil:a circuit for all seasons”,IEEE Solid-state circuits magazine,2015.T-coil based bandwidth broadening 2025 IEEE International Solid-State Circuits ConferenceMain learnings 1Peter Ossieur71 of 75T6:Fron

197、t-end circuit design for high-speed optical transceiversOverview of optical linksFigure of meritIntensity-modulation,direct-detectCoherentModulationOnly amplitudeAmplitude,optical phase,in two orthogonal polarizationsLoss budgetModerateHigh,due to gain of local oscillator laserTransceiver complexity

198、ModerateHigh(er):low-linewidth laser,DSP 2025 IEEE International Solid-State Circuits ConferenceMain learnings 2Comparison of optical transmitters72 of 75Peter OssieurT6:Front-end circuit design for high-speed optical transceiversFigure of meritDirectly modulated laserDirectly modulated VCSELMach-Ze

199、hnder modulatorElectro-absorption modulatorRing modulatorInsertion loss0dB0dBLow to moderateModerateModerateExtinction ratioModerateModerateHigh to moderateModerateModerate to lowOptical bandwidthSingle wavelengthSingle wavelengthHighModerateRequires controlModulation bandwidthLowModerateMedium to h

200、ighHighMediumDriving schemeCurrentswitchingCurrentswitching orvoltage drivenTraveling wave:terminatedamplifiersSwitching smallmodulatorcapacitanceSwitching smallmodulatorcapacitanceSize(area)MediumSmallLargeSmallVery small 2025 IEEE International Solid-State Circuits ConferenceMain learnings 3Peter

201、Ossieur73 of 75T6:Front-end circuit design for high-speed optical transceiversBroadband front-end modulator driversScaling towards high bandwidths:inductive peaking techniquesScaling even higher:traveling-wave amplifiersSiGe BiCMOS driversCMOS driversVoltage swing VModerate:several VppfeasibleLow:st

202、acking required to avoid breakdownGain dBCan be highLowGeneral applicationHigh bandwidth Mach-Zehnder modulatorsLow capacitance lumpedmodulators 2025 IEEE International Solid-State Circuits ConferenceMain learnings 4Peter Ossieur74 of 75T6:Front-end circuit design for high-speed optical transceivers

203、Broadband front-end transimpedance amplifiersRely on feedback of voltage amplifier to break trade-off between achievable transimpedance gain,bandwidth and input-referred noise currentCommon-emitter or common-sourceInverter basedCommon-base or common-gateRegulated common-base or common-gate cascodeIn

204、put impedanceModerateLowVery lowInput-referred noise currentLowModerateModerate 2025 IEEE International Solid-State Circuits ConferenceConclusionPeter Ossieur75 of 75T6:Front-end circuit design for high-speed optical transceivers Significant need for broadband and low-power optical transceivers Driv

205、en by AI applications Need for ultra high-baudrates:targeting 250GbaudLinear modulator drivers with bandwidths 100GHzLinear transimpedance amplifiers with bandwidths 100GHzNeed for ultra low-power optical IO:1pJ/bitCMOS-based“inverter-style”analog designsThere is much more to exploreAutomatic gain and offset control,burst-mode operationEqualization techniques such as continuous-time linear equalizers,feedforward equalizers,decision feedback equalizers