Research And Design Of A Series Of Driver ASICs For High-speed Optical Communication In High Energy Physics Experiments

The Nuclotron-based Ion Collider f A-cility（NICA）is a new accelerator complex designed at the joint institute for nuclear research（Dubna,Russia）to study properties of dense baryonic matter.It will provide a variety of beam species ranged from protons and polarized deuterons to very massive gold ions.The multi-purpose detector（MPD）is one of three detectors in NICA and it has been designed to detect the charged hadrons,electrons and photons in heavy-ion collisions.The requirements of massive information transmission and anti-irradiation at the detector front-end pose a severe challenge to the design of high-speed data transmission link.The VCSEL based optical fiber link has been widely used in detector front-end high-speed data transmission optical links because of its high bandwidth,high density and anti-irradiation.The VCSEL driver ASIC and the optical receiver ASIC are the key and bottom electrical ASICs in optical fiber data transmission system.However,this kind of ASIC is almost monopolized by foreign countries,and has been banned and blocked by domestic technology for a long time.Therefore,it is of great significance to independently develop and apply the VCSEL driver ASIC and the optical transceiver ASIC for high-speed optical communication in high energy physics experiments.The main research work of this thesis is to design the four VCSEL driver ASICs with different driving forms and modulation modes using domestic SMIC 55 nm CMOS technology.Specifically,it includes a 14 Gbps NRZ laser array driver ASIC and a 14 Gbps NRZ single channel optical transceiver ASIC applied to NICA-MPD detector.And a 25Gbps NRZ and a 20 Gbps PAM4 laser array driver ASICs with the background of NICA-MPD detector as the frontier exploration of ultra-high-speed technology.Its specific research content and innovation points are reflected in the following aspects:1.In the 14 Gbps NRZ laser array driver ASIC,the novel output driver circuit based on AC coupling of double feedforward capacitor and cascode current source is proposed for the first time,which greatly improves the circuit bandwidth and optimizes the output eye.The simulation results show that the-3 d B bandwidth is improved from 8.5 GHz to13.5 GHz under the typical corner.The optical test results show that the open and clear optical eye can be obtained at the data rate of 14 Gbps.The RMS jitter of optical eye is 2.6ps with the peak-peak jitter of 16.6 ps,and the optical eye amplitude is 594.2μW with the overall power consumption of 65 m W.2.In 14 Gbps NRZ single channel optical transceiver ASIC,an output driver structure based on capacitive coupling pre-emphasis technology is proposed,which effectively solves the problem of traditional pre-emphasis circuit at the cost of output gain.In addition,the ASIC integrates the driver（Tx direction）and receiver（Rx direction）module design,in conjunction with the external TOSA and ROSA,can achieve 14 Gbps bidirectional high-speed fiber data transmission.The test results show that the RMS jitter and peak-peak jitter of 14 Gbps optical eye are 3.5 ps and 22.5 ps in the laser driver module test（Tx direction）,respectively.In the optical receiver module test（Rx direction）,the RMS jitter and peak-peak-jitter P-P jitter of 14 Gbps electrical eye are 4.7 ps and 23.1 ps,respectively.In the loop（Tx and Rx self-loop）test,the bit error rate of the overall optical fiber transceiver system reaches the design requirement of less than 10^-12.3.In the 25 Gbps NRZ laser array driver ASIC,two kinds of high-speed driver stage designs have been tried and verified successfully.A new output driver circuit in Design I based on AC-coupled CML pseudo-difference structure is proposed for the first time,and the programmable two-tap FFE pre-emphasis technology is combined to expand the circuit bandwidth.The output driver circuit in Design II uses a dual feedforward capacitor with cascode current source structure,and the custom T-Coil inductor technology is proposed to further improve the circuit bandwidth.This ASIC is also the VCSEL driver with the highest measured speed in international high energy physics experimental applications.The simulation results show that,under the default conditions,the bandwidth of the output driver in Design I increases from 10 GHz to 19.5 GHz,and that of the output driver in Design II increases from 13.5 GHz to 18.5 GHz.The optical test results show that the open and clear optical eye can be obtained in both Design I and Design II at the 25 Gbps data rate.The RMS jitter of the Design I is 2.9 ps with the peak-to-peak jitter of 19.5 ps,and the eye amplitude is 445.6μW.The RMS jitter of the Design II is 3.3 ps with the peak-peak jitter of 21.7 ps,and the eye amplitude is 587.6μW.4.In the 20 Gbps PAM4 laser array driver ASIC,a novel PAM4-core output driver is proposed,which combines the Adder stage and the output driver stage,directly converts the two-level voltage signal from the MSB channel and LSB channel to the four-level current signal.The VCSEL is driven to emit light,optimizing and streamlining the conventional PAM4 output driver stage circuit structure.This ASIC is also the first successful attempt and verification of PAM4 form of fiber optic data transmission technology in the field of high energy physics experiments in China.The optical test results show that at the data rate of 20 Gbps,the ASIC can output clear and open PAM4 optical eyes with the eye linearity of 0.97.The TDECQ is 0.63 d B with the eye amplitude of 761.2μW.At present,the four ASICs have been successfully taped-out and tested.The 14 Gbps NRZ laser array driver ASIC and the 14 Gbps NRZ single-channel optical transceiver ASIC have all reached the expected indexes,which can be used in the high-speed data transmission system of NICA-MPD detector front-end readout electronics.Taking the NICA-MPD detector as the background,as the development of high bandwidth technology,the 25 Gbps NRZ and the 20 Gbps PAM4 laser array driver ASICs have very positive promoting and guiding significance for the research and development of ultra-high speed data transmission in high energy physics experiments.