July MERITA:Methodology to Evaluate Radiation in Information Technology Application 1 MERITA methodologies and software solution Alessandro Arnulfo Carla Giachino H.D.T. Italia s.r.l.

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 2 MERITA methodologies and software solution Starting Point Power planes modelling PRESTO_POWER environment

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 3 MERITA methodologies and software solution PRESTO_POWER environment Starting point: –One (eventually all) of the simulation levels available in PRESTO_POWER ver. 1.0: signal transmission trace crosstalk simultaneous switching noise trace supply distribution analysis trace radiated emission evaluation what-if analysis

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 4 MERITA methodologies and software solution PRESTO_POWER environment CAD Extraction Sim. Set up Creation of SPRINT netlist SPRINT Evaluation of radiated field Display of spectrum radiated field Link of circuital model of planes to the other circuit elements. Estimation of field radiated by loops Emission maps display Extraction of areas and planes shape Possibility to model planes or not and to take into account loops or not

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 5 MERITA methodologies and software solution Thank you for your attention. Alessandro Arnulfo is going to present you now details on MERITA software solution

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 6 MERITA methodologies and software solution POWER PLANES MODELLING CURRENT LOOP ANALYSIS

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 7 MERITA methodologies and software solution Phenomena requiring power/ground planes modelling Power planes model Current Loops Analysis

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 8 MERITA methodologies and software solution Power planes modelling is necessary to simulate effects such as: Ground Bounce Filtering Current Loops Radiation

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 9 MERITA methodologies and software solution GROUND BOUNCE input stage from driver interconnection and loads VCC GND Iout Vcc lead Gnd lead ChipVcc ChipGnd to other outputs and inputs of the chip Vout Vsso Ground bounce occurs when one digital output switches, due to the fact that a chip is incapsulated in a package with non- ideal pins.

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 10 MERITA methodologies and software solution Output state change Charge drained through lead inductances Current pulses inducing Voltage drops GROUND BOUNCE

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 11 MERITA methodologies and software solution Internal circuitry operates with a different ground reference If ground bounce exceeds logic thresholds, false logic transitions can occur GROUND BOUNCE consequences: Output bouncing below ground The negative voltage may be large enough to damage the input of the IC being driven

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 12 MERITA methodologies and software solution Power planes modelling is necessary to simulate the noise propagation and ground bounce effect on signals

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 13 MERITA methodologies and software solution FILTERING Gate Power source Very large power supply inductance Power supply input droops to zero The gate may no longer work or break into oscillation

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 14 Gate Power source Bypass capacitor MERITA methodologies and software solution - Bypass capacitor insertion - Filtering through interplane capacitance between power planes SOLUTION:

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 15 MERITA methodologies and software solution Power planes modelling is necessary to simulate the power planes filtering effect optimize bypass capacitors placement on a PCB

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 16 MERITA methodologies and software solution POWER PLANES MODELLING

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 17 MERITA methodologies and software solution Metal areas modelling: POWER NET :PLANES SPLITTED PLANES SIGNAL NET Areas Connections Topology SEGMENT - AREA VIA - AREA PIN - AREA

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 18 MERITA methodologies and software solution 50% 0% 100%

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 19 MERITA methodologies and software solution Z 2Z UNIFORM Td

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 20 MERITA methodologies and software solution Circuital Simulator: SPRINT Based on Digital Signal Processing technique Works in Time Domain, with fixed Time step Simple algorithm Speed Robustness Simulation time  number of nodes

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 21 MERITA methodologies and software solution Grid choice analysis Each metal area can have a different, optimized grid step Parameters related to the grid step: Tstep:minimum time resolution Max Nrow, max Ncoluser-defined grid limits Tstep Propagation speed Dstep (space resolution) Cells must have dimensions multiple of dstep and can not be more than N

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 22 MERITA methodologies and software solution Characteristic impedances are evaluated depending on the cross-section: MICROSTRIP STRIPLINE

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 23 MERITA methodologies and software solution Planes modelling user interface: The user can choose to model signal and power areas or not Gridding settings

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 24 MERITA methodologies and software solution CURRENT LOOP ANALYSIS

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 25 MERITA methodologies and software solution Differential Mode Current Loop: BYPASS LOOP currents flowing between the power pins of Ics and bypass capacitance SIGNAL LOOP currents on lines driven by output pins with their return on ground plane Now evaluated by PRESTO_POWER Already taken into account by EmiR

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 26 MERITA methodologies and software solution BYPASS LOOP VCC GND IC ELM NOISE

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 27 MERITA methodologies and software solution TL Cload Ron L Cb ILoop Rin Lpkg Cin Zin 2 1 Passing-through current F res = 1 / 2  Lpkg Cin

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 28 MERITA methodologies and software solution Evaluation of radiation spectrum of bypass loop currents in near field condition: Zin seen at power pins Logical ports rise time Loop area (package-dependent) Distance (1/ r 2 ) VCC GND IC Lsocket & Lpin Interplane cap.

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 29 MERITA methodologies and software solution Display of results: Emission Maps Board areas are coloured depending on the emission value, at a user-selected frequency or over the whole freq. range

July MERITA:Methodology to Evaluate Radiation in Information Technology Application 30 MERITA methodologies and software solution Thank you for your attention.