Reflection suppression methods EECS 713 Liyao Wang

Outlines  Theory  Simulation circuit  Termination Source termination Load termination Thevenin termination RC termination Diode termination

Theory Figure_1

Theory Figure_2 [1] Figure_3 [1]

Simulation circuit

Simulation Result

Source termination Advantage 1)Easy to assemble 2)Reduce ringing 3)Increase signal integrity 4)Reduce EMI Disadvantage 1)Load reflection still there 2)Increase the rise time of input signal 3)Wasting power

Source termination

Simulation result

Load termination Advantage 1)Easy to assemble 2)Reduce ringing 3)Easy to find the resistor value Disadvantage 1)Increase power consumption

Load termination

Simulation result

Thevenin termination

Advantage 1)Good overshoot suppression Disadvantage 1)Large current drive (increase power consumption) 2)Increase the difficulty of layout 3)Hard to choose the resistor value and Vcc value

Thevenin termination

Simulation result

RC termination Advantage 1)Absorbing all the reflection wave 2)Low power consumption Disadvantage 1)Increase signal delay 2)The time constant of RC circuit may cause reflection 3)In high speed digital design, need to be careful of the capacitor value

RC termination

Simulation Result

Reference [1] Paul, Clayton R., Introduction to Electromagnetic compatibility, Wiley Series in Microwave and Optical Engineering, [2]Wakerly, John F., Digita l Design Principles and Practices, Pearson Education, Inc., [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