EMC Expert System for Architecture Design

Transcription

1 EMC Expert System for Architecture Design EMC Expert System for Architecture Design Marcel van Doorn Philips Electromagnetics Competence Center High Tech Campus 26, 5656 AE Eindhoven 12 June 13 2 Trends & Needs TRENDS Semiconductors technology: frequencies increase and rise/fall times decrease (ITRS) / 32 emission standard for multimedia products: NEEDS October 11 upper test frequency raised from 1 to 6 GHz To minimize interference in GHz communication bands New EMC design guidelines for high-speed interfaces (up to 6 GHz) 3 4 1

2 Trends: Semiconductors technology * Transistor gate length (nm) On-chip local clock (GHz) Chip-to-board (GHz) High-speed differential buses (point-to-point) Equiv. switching edge rate (ps) Supply voltage (V) * Source: International Technology Roadmap for Semiconductors 1 Frequencies Rise/fall-times Supply voltages Noise margin EMISSION IMMUNITY SIGNAL / POWER INTEGRITY PROBLEMS 5 6 EMC Expert System approach Objectives EMC Expert System approach General modeling framework Develop modeling & simulation framework to predict radiated emission behavior at system level (PCB cable enclosure) Implement in 3D EM simulation tool CST MICROWAVE STUDIO Apply Expert System to specific application cases Develop quantitative guidelines for system architectures Design Guide PCB Signal track Cable Grounding point Metal plate Focus on maximum radiated emission according / 32, 3 MHz 6 GHz, 1 m distance wire 3 MHz 6 GHz Make the model as simple as possible, but no simpler! 7 8 2

3 Source model Simulation output: maximum radiation E s R s Transmission line on PCB/cable (microstrip): E s = 1 V (3 MHz 6 GHz) R s = 5 Ω R l = 5 Ω (matched transmission line) Z = 5 Ω (characteristic impedance; h/w.6) I s = signal current = 1/1 =.1 A I i V s Z L trans ε r = 4.7 W R l h ` Radiation pattern at 1 GHz Max 1 m (dbµv/m) E-field Frequency f (MHz) Max E-field on sphere with radius 1 m as a function of frequency 9 1 Simulation cases Max radiated field at 1 m from source Parameter studies Single board Track length, height above ground Distance track to board edge (h-rule) Wire length Cable Microstrip vs. co-planar strip Size pig tail Enclosure With and without metal plate; amount of ground connections Distance PCBs and cable to metal plate

4 PCB design rules: Track height PCB design rules: Edge distance 1 8 W h 5 Ω microstrip; length = 1 mm 8 7 1m (dbuv/m) W=.4mm h=.3mm W=.16mm h=.1mm W=2.8mm h=1.6mm m (dbuv/m) mm 2mm 1mm PCB design rules: Ground wire 1m (dbuv/m) L wire 5 Ω microstrip; length = 1 mm 1mm 5mm -1 1mm

5 Cable design rules: Microstrip vs. co-planar strip Cable design rules: Pigtail size (dbuv/m) Ω cable; length = 3 mm Microstrip: W s =.1mm; h c =.5mm Coplanar: S=.1mm;W s =.1mm m (dbuv/m) 1 8 L pig 5 Ω cable; length = 3 mm Pigtail=mm Pigtail=1mm Pigtail=1mm Enclosure design rules: PCB height above metal (dbuv/m) 1 8 hpcb=1mm hpcb=1mm hpcb=1mm h pcb Metal plate PCB dimension = 1 1 mm 5 Ω microstrip; length = 1 mm 5

6 Enclosure design rules: Signal track at top or bottom Enclosure design rules: Number of grounding (dbuv/m) 1 8 top bottom 4 ground connections at corners signal - signal (dbuv/m) gnd connection= gnd connection=4 gnd connection=52-1 mm - PCB dimension = 1 1 mm Enclosure design rules: Complete architecture vs. PCB (dbuv/m) 1 8 wire PCB1 cable Metal plate PCB2 PCB1 stand alone PCB1 embedded in system stand alone - embedded

7 Demo: radiation cavity resonator Test Set-up PCB above metal plate h 5 Ω 1 cm microstrip h track = 1.6 mm, W track =.5 mm, W ground = 26 mm, ε r = 4.7 To Tracking Generator (TG) Metal plate Demo: radiation cavity resonator PCB 2.6 mm above metal plate vs. no plate 1 SA VIEW U SA 2 SA VIEW (dbµv) TG dbm Ref TG 8 = dbµv dbm = 224 * Att mv db Max. E-field at 3 cm D1 3 dbµv * RBW 1 khz 1 GHz VBW 3 khz SWT 1.35 s Legal field limit at 3 cm (7 dbµv/m) A PRN PCB 2.6 mm above metal plate No metal plate (PCB in free space) 1 PCB above metal plate; Signal track on bottom side between PCB ground plane and metal plate No connections between PCB ground and metal plate -1 - Start 3 MHz Frequency Stop 3 GHz 25 Date: 13.JAN.1 15:19:23 26 Demo: radiation cavity resonator PCB 2.6 mm above metal plate vs. 14 mm U SA 2 SA VIEW (dbµv) 3 SA VIEW TG dbm Ref TG 8 = dbµv dbm = 224 * Att mv db Max. E-field at 3 cm -1 D1 3 dbµv * RBW 1 khz 1 GHz VBW 3 khz SWT 1.35 s Legal field limit at 3 cm (7 dbµv/m) A PRN PCB 2.6 mm above metal plate PCB 14 mm above metal plate - Start 3 MHz Frequency Stop 3 GHz Date: 13.JAN.1 16::

8 Summary New quantitative EMC design guidelines at board, cable and enclosure level have been developed with 3D EM simulations. With these guidelines electronic designers can make the right choices during the early architecture phases: PCB technology? Routing critical signals? Cable/connector technology? Additional shielding measures? Position PCBs, cables, and metal plates? Number of grounding connections? Etc. Thank you for your attention! Questions? Paper APEMC 11 Korea (Jeju) EMC Expert System for Architecture Design, Marcel van Doorn 29 3 Acknowledgement This work is supported by the Eniac Joint Undertaking project Enlight: Energy efficient and intelligent lighting systems 32 8