Journal of the Institute of Electronics Engineers of Korea SC (전자공학회논문지SC)

The Institute of Electronics and Information Engineers (대한전자공학회)
권호 표지

A Study On Effects of The Termination Conditions on Crosstalk in The A/D Converter Circuit

A/D 변환기 회로에서 터미네이션 임피던스의 crosstalk에 대한 영향 분석

  • Lim, Han-Sang (Department of Electronics Convergence Engineering, Kwangwoon University)
  • 임한상 (광운대학교 전자융합공학과)
  • Received : 2009.08.11
  • Accepted : 2010.03.09
  • Published : 2010.03.25
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, crosstalk between dominant interconnect pairs in an A/D converter circuit is analyzed in frequency domain and effects of termination conditions on crosstalk are described, based on the practical circuit conditions. An A/D converter circuit is a mixed circuit where both clean and noisy signals coexist such that the circuit probably suffers from distortion by crosstalk. An analog input signal and the reference voltage signal, which dominate the overall conversion performance of the A/D converter circuit, are ready to be distorted by crosstalk and include specific termination conditions, such as non-matching and capacitive termination, respectively. Thus, this study presents the model of crosstalk considering impedance mismatch at both ends and analyzes effects of the practical termination conditions in the analog input and the reference voltage interconnects on crosstalk. A typical circuit configuration of the two interconnects is described and crosstalk including near-end and far-end termination impedances is modeled. Effects of the near-end impedance mismatch in the analog input interconnect and the far-end capacitive termination in the reference voltage interconnect are estimated in the frequency domain by using the model of crosstalk and experiments are performed to confirm the estimated results. Microstrip lines are used as interconnects, involving the increase of loss in high frequencies.

본 논문은 A/D 변환기(Analog-to-Digital Converter) 회로에서 신호선의 터미네이션 조건이 crosstalk에 의해 왜곡되기 쉬운 특성을 가지며 동작 주파수가 높아짐에 따라 이에 대한 주의가 더욱 요구된다. 그중에서도 아날로그 신호인 입력 신호와 레퍼런스 전압 신호는 crosstalk에 의해 왜곡되기 쉬운 아날로그 신호이면서, A/D 변환 전체의 동작 성능을 좌우하는 신호들이다. 이 두 신호들은 각각의 회로 구성에 따라 독특한 터미네이션 조건을 가지므로 본 논문에서는 주파수 영역에서 임피던스 불일치 조건을 고려한 crosstalk를 모델링하고 해당 터미네이션 조건이 crosstalk에 미치는 영향을 확인한다. 먼저, A/D 변환기 회로에서 두 신호의 회로 구성을 파악한 후 near-end와 far-end에서 임피던스 불일치를 고려한 crosstalk 모델을 유도한다. 유도한 crosstalk 모델을 이용하여 입력 신호의 near-end와 터미네이션 임피던스 불일치와 레퍼런스 전압 신호의 far-end 커패시턴스 터미네이션이 crosstalk에 미치는 영향을 예측하고, 실험을 통해 예측 결과를 확인한다. 신호선으로는 가장 널리 사용되는 microstrip 구조를 사용하였으며 skin effect에 의한 손실 증가를 반영하였다.

Keywords

References

  1. D.A. Hill, K.H. Cavcey, and R.T. Johnk, "Crosstalk between microstrip transmission lines," IEEE Trans. Electromagnetic Compatibility, Vol. 36, No. 4, pp. 314-321, November 1994. https://doi.org/10.1109/15.328861
  2. T.T. Yan and M.Z. Zenu, "Capacitive and inductive couplings of PCB traces," TENCON 2000, Vol. 1, pp. 186-191, 2000.
  3. P.F. Wahid, M. Fletcher, A. Abei, and M.A. Belkerdid, "Modeling of crosstalk in coupled microstrip lines," IEEE Conference Proceedings, Southeastcon '88, pp. 506-510, 1988.
  4. S. Malisuwan and V. Ungvichian, "A Study of crosstalk applied to ultra high speed parallel lossy micro and strip lines with shielding effectiveness," 1999 International Symposium on Electromagnetic Compatibility, pp. 742-745, 1999
  5. S.V.K. Shastry and M.N. Rao, "Electromagnetic coupling and radiation analysis if lossy multiconductor lines in high speed switching circuits," 1995 International Symposium on Electromagnetic Compatibility, pp. 125-130, 1995.
  6. H.J. Park, Y. S. Sohn, J.C. Lee, and S.I. Cho, "Empirical equations on electrical parameters of coupled microstrip lines for crosstalk estimation in printed circuit board," IEEE Trans. Advanced Packaging, Vol. 24, No. 4, pp. 521-527, 2001. https://doi.org/10.1109/6040.982839
  7. C.S. Walker, Capacitance, Inductance, and Crosstalk Analysis, Artech House, 1990.
  8. M.S. Lin, "Measured capacitance coefficients of multiconductor microstrip lines with small dimensions," IEEE Trans. Components, Hybrid, and Manufacturing Technology, Vol. 13, No. 4, pp. 1050-1054, 1990. https://doi.org/10.1109/33.62547
  9. S. Voranantakul, J.L. Prince, and P. Hsu, "Crosstalk analysis for high speed pulse propagation in lossy electrical interconnections," IEEE Trans. Components, Hybrid, and Manufacturing Technology, Vol. 16, No. 1, pp. 127-136, February 1993. https://doi.org/10.1109/33.214869
  10. B.L. Hart, Digital Signal Transmission Line Circuit Technology, Van Nostrand Reinhold, 1988.
  11. X. Luo, F. Sha, J. L. Drewniak, T.P. Van Doren and T. Anderson, "Lumped-element Sections for Modeling Coupling between High-speed Digital and I/O Lines," Proceedingd of International IEEE EMC Symposium, pp. 260-265, 1997.
  12. D. Woods, "Multiport-network analysis by matrix renormalisation employing voltage=wave s-parameter with complex normalisation," Proc. IEE, Vol. 124, pp. 198-204, March 1977.
  13. Arbitrary impedance, Anritsu Application Note revision B, pp. 1-12, 2002.