Title Page
Abstract
Contents
Chapter 1. Introduction 15
1.1. Motivation 15
1.2. Thesis Organization 18
Chapter 2. Background of Simultaneous Bidirectional Transceiver 19
2.1. Overview 19
2.2. Basic Architectures 24
2.3. Hybrid 30
2.3.1. Replica Hybrid 31
2.3.2. Resistor-Transconductor (R-gm) Hybrid 34
2.3.3. Wide Linear Range (WLR) Hybrid 38
Chapter 3. Design of Asymmetric SBD Transceiver with Two-Step Hybrid 41
3.1. Overview 41
3.2. Analysis on Wide Linear Range (WLR) Hybrid 45
3.3. Proposed Two-Step Hybrid Strategy 50
3.4. SBD Transceiver Implementation 55
3.4.1. Serializer Chip (SER) 57
3.4.2. Deserializer Chip (DES) 63
3.5. Measurement 70
Chapter 4. Design of Symmetric SBD Transceiver with Hybrid Adaptation 80
4.1. Overview 80
4.2. Proposed Hybrid Adaptation Scheme 83
4.3. SBD Transceiver Implementation 88
4.3.1. Transmitter 90
4.3.2. Receiver 95
4.3.3. Clock Distribution 99
4.4. Measurement 102
Chapter 5. Conclusion 109
Bibliography 111
초록 123
Table 3.1. Performance summary and comparison with prior SBD transceivers 79
Table 4.1. Performance summary and comparison with prior symmetric SBD transceivers 108
Fig. 1.1. Number of published papers on wireline SBD transceivers by year. 16
Fig. 1.2. Per-pin data rates of SBD transceivers by year. 16
Fig. 2.1. Comparison of unidirectional and bidirectional communications. 20
Fig. 2.2. Examples of symmetric SBD signaling applications. 21
Fig. 2.3. Examples of asymmetric SBD signaling applications. 21
Fig. 2.4. (a) Operational principle of PAM-4 signaling and (b) power spectral density of NRZ and PAM-4 signals with same data rate. 22
Fig. 2.5. Eye diagrams of overlapped signals in symmetrical SBD communication using (a) NRZ and (b) PAM-4 signaling. 23
Fig. 2.6. Concept of time division duplexing (TDD). 25
Fig. 2.7. Concept of frequency division duplexing (FDD). 25
Fig. 2.8. (a) Conceptual diagram of SBD transceiver using active cancellation. (b) Separation process of active cancellation. 26
Fig. 2.9. Near-end/far-end echoes in SBD transceiver. 27
Fig. 2.10. Basic architecture of wireline SBD transceiver (single side). 28
Fig. 2.11. Structure of conventional replica hybrid. 31
Fig. 2.12. Implementation example of a subtraction stage. 32
Fig. 2.13. Structure of switched-capacitor hybrid. 33
Fig. 2.14. (a) Conceptual structure and (b) separation process of R-gm hybrid. 34
Fig. 2.15. Implementation example of (a) conventional replica hybrid and (b) R-gm hybrid. 36
Fig. 2.16. (a) Structure of WLR hybrid. (b) Operational principle of WLR hybrid (when inbound signal is off). 38
Fig. 3.1. Overall architecture of automotive camera link system. 42
Fig. 3.2. Characteristic of hybrid operation in the asymmetric SBD transceivers. 43
Fig. 3.3. (a) WLR hybrid including an interconnect model and (b) small signal model of the hybrid network. 46
Fig. 3.4. Power overhead and frequency characteristic of WLR hybrid to RHYB.[이미지참조] 48
Fig. 3.5. RLM comparison of hybrid structures to the input voltage swing. 49
Fig. 3.6. Conceptual diagram of SBD structure that emulates PAM-4 drivers including TX FFE using replica. 50
Fig. 3.7. (a) Conceptual diagram of proposed two-step hybrid structure in SER and (b) operational principle of the hybrid structure with a single-bit model. 51
Fig. 3.8. FFT simulation results of FC signal with different hybrid coefficients. 52
Fig. 3.9. Simulated received eye-opening of BC signal to the timing difference between FC driver and hybrid. 54
Fig. 3.10. Simulated FC driver RLM vs. output voltage swing 55
Fig. 3.11. Simulated eye openings of received FC and BC vs. signal swing ratio of FC and BC. 56
Fig. 3.12. SER block diagram with two-step hybrid architecture. 57
Fig. 3.13. Configuration of 6:1 serializer. 58
Fig. 3.14. Schematic of PAM-4 FC driver (including pre-driver) and hybrid. 58
Fig. 3.15. Structure of 2nd order gm-C LPF.[이미지참조] 59
Fig. 3.16. Signal spectra of FC and BC after hybrid in SER. 60
Fig. 3.17. Eye diagrams of received BC signal with 1st and 2nd order LPF.[이미지참조] 61
Fig. 3.18. Frequency response of gm-C LPF. 62
Fig. 3.19. Vertical/horizontal margins of received BC signal to Q factor. 62
Fig. 3.20. DES block diagram with WLR hybrid and echo canceller. 63
Fig. 3.21. Schematic of BC driver and WLR hybrid network. 64
Fig. 3.22. (a) Overlapped hybrid input under SBD operation. Outputs of WLR hybrid (b) without attenuator, (c) with passive attenuator, and (d) with active PGA instead of passive attenuator. 65
Fig. 3.23. Configuration of FC RX data path. 66
Fig. 3.24. Frequency response of PGA including passive attenuator 67
Fig. 3.25. Frequency response of CTLE (DC gain control). 68
Fig. 3.26. (a) A single-bit response of BC with 5-m automotive cable and (b) echo waveforms with and without echo canceller. 69
Fig. 3.27. Measurement setup of SBD transceiver. 70
Fig. 3.28. Measured channel characteristics of 5-m STQ cable. 71
Fig. 3.29. Measured transmitter output waveform of PAM-4 FC signal. 73
Fig. 3.30. Measured transmitter output waveform of PAM-2 BC signal. 73
Fig. 3.31. Measured spectra of SER intermediate nodes. 74
Fig. 3.32. Measured spectra of DES intermediate nodes. 74
Fig. 3.33. Measured bathtub curve of FC data under SBD operation. 76
Fig. 3.34. Measured bathtub curves of BC data under SBD operation with two hybrid coefficients. 76
Fig. 3.35. Measured JTOL curves of 12-Gb/s PAM-4 FC data. 77
Fig. 3.36. Measured JTOL curves of 125-Mb/s PAM-2 BC data. 77
Fig. 3.37. Chip photomicrographs of SER and DES. 78
Fig. 3.38. Power breakdown of SBD transceiver. 78
Fig. 4.1. Conceptual block diagram of SBD transceiver with hybrid adaptation engine. 81
Fig. 4.2. Operational principle of proposed hybrid adaptation scheme. 83
Fig. 4.3. Truth table of (a) pattern filter for hybrid adaptation and (b) hybrid weight adaptation logic. 84
Fig. 4.4. Simulated results of (a) normalized VEO by the normalized hybrid weight and (b) eye diagrams by the hybrid mismatches. 86
Fig. 4.5. Block diagram of overall PAM-4 SBD transceiver architecture. 88
Fig. 4.6. Schematic implementation of final 2:1 serializer. 90
Fig. 4.7. Schematic of driver and hybrid. 91
Fig. 4.8. Simulated waveforms of PAM-4 hybrid operation. 92
Fig. 4.9. Simulated eye diagrams of hybrid (a) input and (b) output. 93
Fig. 4.10. Simulated output impedance of driver including hybrid. 94
Fig. 4.11. (a) Schematic and (b) frequency response of CTLE. 95
Fig. 4.12. Logical operation of dLev adaptation. 96
Fig. 4.13. Logical operations of SS-MMPD in PAM-4 using one error sampler. 97
Fig. 4.14. Simulated locking transients of adaptation loops. 98
Fig. 4.15. Simulated PI locking behaviors with different hybrid weights. 98
Fig. 4.16(a) Schematic of PI and (b) interpolated phase by control code. 99
Fig. 4.17. Conceptual diagram of data alignment technique. 100
Fig. 4.18. Chip photomicrograph and power/area breakdown. 102
Fig. 4.19. Measured frequency response of channel. 103
Fig. 4.20. Output waveform of PAM-4 transmitter. 103
Fig. 4.21. Measurement setup of SBD transceiver. 104
Fig. 4.22. Measured bathtub curves of 40-Gb/s UD and 80-Gb/s SBD transceiver. 106
Fig. 4.23. Measured JTOL curves of 40-Gb/s UD and 80-Gb/s SBD transceiver. 106
Fig. 4.24. Measured BER of SBD transceiver by hybrid weight. 107
Fig. 4.25. Measured BER of SBD transceiver by phase difference of SBD signals. 107