DesignCon 2011 Methods for Discovering and Mitigating Switching Regulator Noise Coupling for Complex PCB System

Server boards and other complex PCB systems are experiencing more densely routed IOs and have an increasing number of power rails that make it challenging to control switching voltage regulator (VR) noise. Our server board design flow has been required to address increasing occurrences of reduced signal margin, memory failures, unreliable booting and system hangs. In this paper we describe multiple VR noise coupling mechanisms we have observed in our server board designs and our application of various analysis methods to discover the root cause and mitigate VR noise coupling issues. We share our comparisons for multiple designs of analysis versus lab measurements and also discuss near field scanning measurements, which have discovered further potential coupling mechanisms.

[1]  Abraham Pressman,et al.  Switching Power Supply Design , 1997 .

[2]  David Pommerenke,et al.  Finding return current paths via synchronized measurements in a multiphase DCDC buck converters , 2009, 2009 IEEE International Symposium on Electromagnetic Compatibility.

[3]  K. Slattery,et al.  Measuring the electric and magnetic near fields in VLSI devices , 1999, 1999 IEEE International Symposium on Electromagnetic Compatability. Symposium Record (Cat. No.99CH36261).

[4]  Keong Kam,et al.  EMI prediction in switched power supplies by full-wave and non-linear circuit co-simulation , 2009, 2009 IEEE International Symposium on Electromagnetic Compatibility.

[5]  Xiaoning Ye,et al.  Switching voltage regulator noise coupling to signal lines in a server system , 2010, 2010 IEEE International Symposium on Electromagnetic Compatibility.

[6]  Keong Kam,et al.  EMC guideline for synchronous buck converter design , 2009, 2009 IEEE International Symposium on Electromagnetic Compatibility.