Presentation on theme: "1 www.cst.com Internal loop Slot Strap ESD simulator Cable to the Oscilloscope Point A Point B CST STUDIO SUITE™ 2006 EMC - Application and Feature Tutorial."— Presentation transcript:
1 www.cst.com Internal loop Slot Strap ESD simulator Cable to the Oscilloscope Point A Point B CST STUDIO SUITE™ 2006 EMC - Application and Feature Tutorial Immunity to ESD on ITE / Lightning and NEMP E. Leroux
2 www.cst.com 3 Immunity to ESD on ITE equipments. ESD generators, immunity test, ITE equipments definitions Induced voltage in a square loop located inside an enclosure-ESD to VCP Discharge Coupling Application to another type of equipment: Discharge on an Cellular Phone Metal Wall Strap Simulator Body Internal loop Slot Strap ESD simulator Cable to the Oscilloscope Point A Point B
3 www.cst.com 4 Definitions ESD Background Electrostatic Discharge (ESD) is the abrupt release of charge from one object (often a person) to another. Such a discharge can permanently damage or otherwise upset the function of sensitive electronic circuits. Electronic products are tested for ESD immunity to insure their continued reliable operation if subjected to realistic levels of ESD after being placed in service. The European Union’s EMC Directive mandates ESD immunity testing for virtually all electrical and/or electronic products as a condition for obtaining the CE Mark before shipping to a member state of the European Union. Applicable Standards Generic Immunity Standards, Product Standards and Product Family Standards require that ESD tests be performed in accordance with specific Basic EMC Standards: IEC 801-2, IEC 61000-4-2, or EN 61000-4-2.
5 www.cst.com Conception of a ESD generator model ESD generators are widely used for testing the robustness of electronic equipment against human-metal ESD. ESD can disturb systems by its current and the associated fields. To predict the susceptibility of a system, a sufficiently accurate model of the ESD generator (gun) is needed. In this first part a simplified ESD generator model is presented using MWS. The current distribution on the generator is not predicted as long as the geometry of the generator and the ground strap are not part of the model. Therefore the problem of simultaneously calculating an ESD generator and a susceptible structure becomes feasible With courtesy of S. Caniggia: ITALTEL, D. Pommerenke, W. Kai: University of Missouri-Rolla In the next slide, ESD generator discharged into a large ground plane In order to verify the ESD generator model, the discharge into a large ground plane was simulated. The current injected from the ESD generator into a large metal wall was measured, and the generator was numerically modeled as in this figure. The geometry of the ESD generator was optimized for obtaining a good match to the measurement, while keeping it as simple as possible.
6 www.cst.com ESD Generator Modelling Metal Wall Strap Simulator Body Measurement Simulation 1KV Discharge current in the standard tip
7 www.cst.com Induced voltage in a square loop located inside an enclosure Internal loop Slot Strap ESD simulator Cable to the Oscilloscope Point A Point B Measurement Simulation The electromagnetic field due to the ESD current between the points A and B excites the enclosure. The square loop placed into the cavity senses the internal electromagnetic field and is then used to compare numerical and experimental values. Same enclosure and measurements set up as in Graziano Cerri, Roberto De Leo, Roberto De Rentiis, Valter Mariani Primiani. “ESD Field Penetration Through Slots into Shielded Enclosures: A time Domain Approach”. IEEE Trans. on EMC, Vol. 39, NO. 4, November 1997. Induced voltage in the square loop for the first 10 ns
8 www.cst.com Typical test setup for discharges to the VCP The proposed model of the ESD generator was tested on the horizontal coupling plane (HCP) and the vertical coupling plane (VCP). We study the coupling with a mouse cable, which was added parallel to the VCP as a susceptible circuit.
9 www.cst.com ESD to VCP Discharge Coupling Measurement Simulation Using the simplified model of the ESD generator, the voltage induced on the cable is simulated, and the results are compared with the results obtained in David J. Pommerenke, Thomas P. Van Doren, Wang Kai, ‘ESD Currents and Fields on the VCP and the HCP Modeled Using Quasi- static Approximations’, IEEE Int. Sym. EMC, Minneapolis, Minnesota, 2002.
10 www.cst.com Using a UDF as an excitation function and a simplified ESD generator model, the induced currents and fields, as seen during susceptibility test, can be modeled using MWS. Within the accuracy bandwidth of the model, the results agree well with the measurements. A higher accuracy is achieved in the model presented relative to enforcing a current in disregard to the ESD generator geometry and internal components. Relative to the fully detailed model of the charging and rapid discharging process, the ability to design ESD generators via numerical techniques is lost. However, sufficient accuracy to predict susceptibility is maintained creating much shorter calculation times. The same ESD “gun” model idea can be used to test other devices and not only ITE equipments….other UDF can be used to deal with other EMC tests… Conclusions
11 www.cst.com Discharge on an Cellular Phone Similar Device Measurement Simulation
12 www.cst.com Another example of EMC simulation with MWS INDUCED CURRENT ON A RADAR DUE TO A DIRECT LIGHTNING STRIKE
13 www.cst.com Another example of EMC simulation with MWS: Nuclear EM Pulse – NEMP coupling with an antenna array
14 www.cst.com Array of patch antenna above a finite ground plane exited by the NEMP (plane wave)