reflection suppression methods eecs 713 liyao wang
TRANSCRIPT
Outlines
TheorySimulation circuitTermination• Source termination• Load termination• Thevenin termination• RC termination• Diode termination
Theory
𝑍 𝑠≠𝑍0≠𝑍𝐿
Reflection 1: Source reflectionReflection coefficient:
Reflection 2:Load reflectionReflection coefficient:
Figure_1
Theory
Figure_2[1]
Figure_3[1]
Set the voltage source as a dc source in which Vdc=100V, =150Ω, and =(10^16)
Source termination
• Advantage1) Easy to assemble2) Reduce ringing3) Increase signal integrity4) Reduce EMI
• Disadvantage1) Load reflection still there2) Increase the rise time of input signal3) Wasting power
Load termination
• Advantage1) Easy to assemble2) Reduce ringing3) Easy to find the resistor value
• Disadvantage1) Increase power consumption
Thevenin termination
• Advantage1) Good overshoot suppression
• Disadvantage1) Large current drive (increase power consumption)2) Increase the difficulty of layout3) Hard to choose the resistor value and Vcc value
RC termination
• Advantage1) Absorbing all the reflection wave2) Low power consumption
• Disadvantage1) Increase signal delay2) The time constant of RC circuit may cause reflection3) In high speed digital design, need to be careful of the
capacitor value
Reference
[1] Paul, Clayton R., Introduction to Electromagnetic compatibility, Wiley Series in Microwave and Optical Engineering, 2006.[2]Wakerly, John F., Digita l Design Principles and Practices, Pearson Education, Inc., 2006.[3] R. Jagdale, A. Reddy, and K. Sundeep, “Optimization of reflection issues in high speed printed circuit boards,” in Proceedings of the 12th International Conference on Networking, VLSI and Signal Processing, pp. 108–112, World Scientific and Engineering Academy and Society, 2010