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EMC measurements of components

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1 EMC measurements of components

2 Summary EMC problem examples EM disturbance sources
EMC certification ? EMC measurement for electronic systems EMC measurement for integrated circuits April 17

3 EMC problem examples A typical electromagnetic environment… April 17

4 EMC problem examples Electromagnetic interference issues in medical devices Medical device EMI problems reported by FDA between 1979 and 1993 EMI types Reported cases Devices Conducted interference 20 (1 death) Cardiac monitor, infusion device, defibrilator… Radiated interference 55 (4 deaths) Pacemaker, ventilator, cardiac monitor LF magnetic field 6 (1 death) Respirator, pacemaker ESD 10 Respirator, infusion pump 405 suspected EMI problems reported by FDA between 1994 and 2005, with 6 deaths, 170 injuries and 167 malfunctions. 72 % of cases concern implantable devices. April 17

5 EMC problem examples Electromagnetic interference issues in military systems 29th July 1967 : accident of the American aircraft carrier USS Forrestal. The accidental launching of a rocket blew gas tank and weapon stocks, killing 135 persons and causing damages which needed 7 month reparations. Investigations showed that a radar induced on plane wiring a sufficient parasitic voltage to trigger the launching of the rocket. H.M.S. Sheffield catastrophe: “During the Falklands War, the British Ship H.M.S Sheffield sank after being hit by an Exocet missile. Despite the Sheffield having the most sophisticated antimissile defense system available, the system created EMI to radiocommunications to and among the contingent of Harrier jets assigned to the ship. While the Harriers took off, the missile defense was disengaged to allow communications with the jets and provided a window of opportunity for the Exocet missile.” April 17

6 EMC problem examples Electromagnetic interference issues in automotive
Interference Technology – October 2011 Mercedez-Benz case: “During the early years of ABS, Mercedez-Benz automobiles equipped with ABS had severe braking problems along a certain stretch of the German autobahn. The brakes were affected by a near-by-near radio transmitter as drivers applied them on the curved section of highway. The near-term solution was to a erect a mesh screen along the roadway to attenuate the EMI. This enabled the brakes to function properly when drivers applied them…. Eventually, automobile ABS was qualified by EMI testing prior to procurement.” April 17

7 EMC problem examples Electromagnetic interference issues in aviation
« Disturbances of flight instruments causing trajectory deviations appear when one or several passengers switch on electronic devices. » (Air et Cosmos, April 1993) NASA publication 1374 (1986 – 1995) FAA Aviation Safety Reporting System has reported 12 cases of interference in aircraft due to personal electronic devices since 2002. April 17

8 EMC problem examples Electromagnetic interference issues in space aircraft Vacuum cleaner incident: “During a Spacelab mission in 1985, the crew decided to use the middeck vacuum cleaner instead of the one in the lab. Switching the middeck vacuum on caused the voltage to drop and the Remote Acquisition Unit to shut off. In preflight EMI tests, the vacuum cleaner had not been tested and should not have been used in the lab. This case shows how careful and attentive one must when dealing with EMC.” [Nasa Publication 1374] April 17

9 Non intentional emission Electrostatic discharge
EM disturbance sources Various disturbance sources that can affect electronic system operation Natural sources Human activity Intentional emission Non intentional emission Electrostatic discharge April 17

10 EM disturbance sources
Interferences from telecommunication systems Radio-navigation Narrowband emission, modulated signals. Regulation and planification of radioelectric spectrum controlled by ITU-R at international level, and by « Agence Nationale des Fréquences » (ANFR) at French level. April 17

11 EM disturbance sources
Interferences from electronic systems Parasitic noise generated by the activity (switching) of any electrical or electronic devices The noiise is usually impulse type  broadband noise. Example : Radiated emission from a 16 bit microcontroller April 17

12 EM disturbance sources
The EM environment according to ITU-R 372-8 Ambient field levels defined from EM survey in 70’s. Recent surveys show a 20 – 40 dB increase in semi-enclosed environment. Example: Survey of the average level of electric field in Canada during the 90’s in urban and suburban environment: between 1 and 20 V/m. April 17

13 Distance antenne – point de mesure = 60m
EM disturbance sources The EM environment Site Agence Nationale des Fréquences (www.anfr.fr) – outil Cartoradio. Distance antenne – point de mesure = 60m Etot = 4.35 V/m Champ E April 17

14 Summary EM disturbances can induce major failures in electronic systems. The parasitic emission and susceptibility to EM disturbances must be tested to ensure electromagnetic compatibility of an electronic systems within a nominal environment. But it is a tedious task because: Diversity in terms of electronic devices Numerous types of disturbances (LF, HF, pulsed, modulated), numerous EM environment Various EM coupling possibilities (conducted, radiated, near-field…) How defining generic tests to guarantee EMC for any electronic systems in any EM environment, with an industrial realism ? April 17

15 The EMC certification EMC European Directive The European directive 89/336/EEC (1996) and then 2004/108/EC (2004) requires that all « electrical apparatus » placed on the European market : Do not produce electromagnetic interferences able to disturb radio or telecom equipments , and the normal operation of all equipments Have a sufficient immunity level to electromagnetic interferences to prevent any degradation of the normal operation. All manufacturers of « electrical apparatus » must certify that the directive is supposed respected by delivering a declaration of conformity and placing a CE mark on the product. CE mark Using harmonized standards adapted to the product to verify the supposition of conformity is recommended April 17

16 The EMC certification R&TTE European Directive The European directive 99/5/EC (1999) Radio & Telecommunications Terminal Equipment which is applied to all telecom and radio equipments emitting on the band 9 KHz – 3000 GHz replace the EMC directive. . R&TTE requires that telecom and radio equipments placed on the European market: : Comply to safety constraints given by the Low Voltage directive (73/23/EEC) (e.g. the limit of EM exposure for persons) and the EMC constraints given by the EMC directive 2004/108/EC. Radio equipments use spectral resources dedicated for terrestrial and spatial communications without generating any interferences. R&TTE mark: Required for all equipments under the R&TTE directive Warning signal for class 2 equipments (special recommandations) April 17

17 The EMC certification International Electrotechnical Commission(IEC)
EMC normative bodies: the importance of EMC standards ! International European International Electrotechnical Commission(IEC) European Commitee for Electrotechnical Standardization (CENELEC) European Telecommunication Standards Institute (ETSI) Comité International Spécial des Perturbations Radioélectriques(CISPR) TC77 Harmonized standards EN 50XXX EN 55XXX EN 6XXXX IEC X CISPR-XX EN 300XX April 17

18 The EMC certification Commercial harmonized standard (non exhaustive list !) Basic standard (general and fundamental rules) EN x (IEC x) EMC – Testing and measurement techniques Generic standard (for equipments in a specific environment) EN (IEC ) Generic Emission Standard, for residential, commercial and light industrial environment EN (IEC ) Generic Immunity Standard, for residential, commercial and industrial environment Product standard (for a specific product family) EN 55022 (CISPR22) Information technology equipment (ITE) EN 55014 (CISPR14) Household appliances, electric tools and similar apparatus EN 55012 (CISPR12) Vehicles, boats and internal combustion engines EN (ETSI ) Electromagnetic compatibility and radio spectrum matters (ERM); Short Range Devices (SRD); Radio equipment to be used in the 25 MHz to MHz frequency range with power levels ranging up to 500 mW; EN (ETSI ) Electromagnetic compatibility and radio spectrum matters (ERM); Short Range devices (SRD); Radio equipment to be used in the frequency range 9 KHz to 25 MHz and inductive loop systems in the frequency range 9 KHz to 30 MHz April 17

19 The EMC certification Commercial harmonized standard (non exhaustive list !) Automotive, military, aerospace and railway industries have developed their own EMC standards. Applications Standard references Automotive ISO 7637, ISO 11452, CISPR 25, SAE J1113 Aerospace DO-160, ED-14 Military MIL-STD-461D, MIL-STD-462D, MIL-STD-461E Railway EN 50121 April 17

20 The EMC certification Case study 1
You want to place on the European market a ventilator for domestic installation. It is supplied by mains (220 V). Which EMC standard(s) should you follow ? What tests should you conduct for the EMC certification ? April 17

21 The EMC certification Case study 1
Application of EN and 2: “Electromagnetic compatibility – Requirements for household appliances, electric tools and similar apparatus” – Part 1 = Emission, Part 2 = Immunity : Any domestic electric/electronic equipments, toys, electric tool supplied under 250 V (monophase) (motors, heat elements, thermostats …) Except light modules (EN55015), radio receivers (EN55025), gaming machine (EN55022). 21 April 17

22 Voltage dips and interruptions
The EMC certification Case study 2 Suggested emission tests: Conducted emission 150 KHz – 30 / 300 MHz Harmonic and flicker Radiated emission 30 MHz – 1 GHz Suggested immunity tests: ESD 4 KV contact / 8 KV air EFT / burst 5/50 ns, 1 KV, 5 KHz repetition Conducted immunity 150 KHz – 230 MHz, 3 V rms Radiated immunity 80 – 1000 MHz, 3 V/m, modulation AM 1 KHz 80% Surge 1 KV 1.2/50 µs pulse on power Voltage dips and interruptions 40 % variations of the power supply, repeated 5× 22 April 17

23 The EMC certification Case study 2
You want to place on the European market a radio emitter/receiver for remote control application in residential environment. The radio emitter use the ISM band around 434 MHz. Its maximum radiated power is limited to 500 mW. The emitter/receiver is an handheld device. Which EMC standard(s) should you follow ? What tests should you conduct for the EMC certification ? April 17

24 The EMC certification Case study 2
The harmonized standard EN : “Electromagnetic compatibility and radio spectrum matters (ERM); Short Range devices (SRD); Radio equipment to be used in the 25 MHz to 1000 MHz frequency range with power levels ranging up to 500 mW” is adapted to short range devices : either with a Radio Frequency (RF) output connection and/or with an integral antenna; for alarms, identification, telecommand, telemetry, etc., applications; with or without speech. It covers fixed stations, mobile stations and portable stations, all types of modulation. April 17

25 The EMC certification Case study 2 List of suggested tests:
Frequency error or drift Does the carrier frequency remains stable? Effective radiated power The radiated power must not exceed a max. level (< 500 mW) Transient power The switching of the transmitter produces interferences in adjacent spectrum Adjacent channel power The power transmitted in adjacent band must be limited. Spurious emissions Parasitic emissions from the emitter and receiver between 9 KHz and ?? Must be limited. Frequency stability under low voltage conditions The emission from the transmitter must remain stable even in extreme low power conditions. Duty cycle The manufacturer must indicate the duty cycle of the equipment Blocking or desensitization Capability of the receiver to receive a wanted signal in presence of unwanted signal Some ESD tests should be also done … April 17

26 The EMC certification Case study 3
You are a semiconductor manufacturers and you want to sell your integrated circuits in the European market. Your ICs are dedicated to automotive applications. Which EMC standard(s) should you follow ? What tests should you conduct for the EMC certification ? April 17

27 The EMC certification Case study 3
If your integrated circuits can not operate by themselves, you don’t need EMC certification. However, your customers will certainly push you to guarantee the low emission and susceptibility of your devices, require measurements, models, support…. Examples of standards providing EMC measurement for ICs: IEC 61967: Integrated Circuits, Measurement of Electromagnetic Emissions, 150 kHz to 1 GHz IEC 62132: Integrated circuits - Measurement of electromagnetic immunity, 150 kHz to 1 GHz ISO11452: Road vehicles - Electrical disturbances by narrowband electromagnetic energy - Component test methods ISO 7637 or IEC /4/5 for ESD, pulse, surge testing. April 17

28 EMC measurement for electronic systems
Why EMC standard measurement methods Check EMC compliance of ICs, equipments and systems Comparison of EMC performances between different products, different technologies, designs, PCB routings Improve interaction between customers and providers (same protocols, same set-up) April 17

29 Radiated or conducted coupling
EMC measurement for electronic systems Emission measurements – General measurement set-up Control - Acquisition Coupling device Coupling network Antennas Wave guide Current clamp… Radiated or conducted coupling Acquisition system Spectrum analyzer EMI receiver Oscilloscope 50Ω adapted path Equipment / Device under test Emission requirements verified ? April 17

30 EMC measurement for electronic systems
Emission measurements – Emission spectrum Amplitude (dBµV) Frequency (MHz) April 17

31 EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver) Frequency adjustment : Start, stop , center Y= power (dBm, dBµV) RBW – frequency resolution, noise floor reduction 50 Ohm input X= frequency VBW – smooth display Emission measurement requires high sensitivity and resolution Emission measurement standards often recommend spectrum analyzer adjustment Amplitude adjustment : Level reference, dynamic. April 17

32 EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver) Principle: based on super heterodyne receiver Input signal Output signal IN Mixer OUT f Fif Frf+Flo IF filter f Frf Local oscillator LO ωif f Flo OUT f Fif IF filter A No Detected power: RBW P = ½.A²+No.RBW April 17

33 EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver) Building blocks and adjustable elements: Detector Input signal Attenuation RBW Envelope detector VBW Mixers Gain IF IF filter Analog filter Attenuator DC blocking Low pass filter Gain log Video filter Local oscillator Display Frequency sweep Reference oscillator Fstart / Fstop Fcenter / Span Point number April 17

34 EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver) Example: effect of RBW and VBW. Measurement of 100 MHz sinus. Amplitude = 90 dBµV Amplitude = 20 dBµV Sweep time : RBW = 100 KHz  2.5 ms RBW = 10 KHz  100 ms Sweep time : VBW = 30 KHz  100 ms VBW = 1 KHz  980 ms April 17

35 EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver) Example: Influence of detector type (peak vs. quasi-peak vs. average). Measurement of radiated emission of a microcontroller. April 17

36 EMC measurement for electronic systems
Radiated emission in (semi-)Anechoic chamber (30 MHz – 1 GHz) EN55022 (Siepel) Absorbents Faraday cage (with absorbents: semi-anechoic chamber) Wide band (calibrated) antenna Device under test 1 m 1 m EMI receiver or spectrum analyzer) R = 3 ou 10 m 1 m Power supply, DUT control April 17

37 EMC measurement for electronic systems
Radiated emission in (semi-)Anechoic chamber (30 MHz – 1 GHz) If far field and free space conditions ensured: Optional pre-amplifier Low loss 50 Ω cable EMI receiver 50 Ω E field Vemi Bilog antenna (or log-periodic, biconical, dipole…) AF = Antenna factor (from calibration) The E field varies in 1/r with the distance r (the radiated power in 1/r²)  possible extrapolation of field intensity. 37 April 17

38 EMC measurement for electronic systems
Radiated emission in (semi-)Anechoic chamber (30 MHz – 1 GHz) Let’s consider a radio receiver (such as a mobile phone). We suppose that it operates at 900 MHz, its antenna has an antenna factor of 29 dB/m, and its receiving floor is -90 dBm. It is placed at 1 m of a “noisy” electronic equipment with a CE Mark. Could you have a risk of interferences ? The noisy equipment with CE mark has certainly passed a radiated emission test in anechoic chamber, so its emission level is certainly less than a given electric field at 900 MHz. We should know the standard followed during the EMC test to deduce the radiated field. An interference can arise if this noisy equipment placed close to the receiver produces an E field larger than the receiving limit of the receiver. Let’s compute the minimum E field that the receiver can detect: the noise floor is given in power on 50 ohms  let’s compute a voltage : V (dBµV) = P (dBm) log R = P (dBm) (if R = 50 ohms)  Pnoise = -90 dBm  Vnoise = 17 dBµV. As the antenna of the receiver has an antenna factor AF = 29 dB/m –> the min E field that the receiver can detect is equal to: Enoise = Vnoise + AF = = 46 dBµV/m. The graph gives the radiated emission limit at 1 m from 3 different standards (class corresponds to different level of severity of the standard): > CISPR22: this product standard is dedicated to ITE (information technology equipment). The level given by this standard are larger than the noise floor of our radio receiver, so an interference can arise. This standard certainly don’t consider the possibility of the presence of a radio receiver at proximity of the ITE equipment. Placed at 3 m, the E field is reduced by 3  - 9dB, so the interference risk is reduced. > CISPR 25 : this product standards concerned any components or electronic modules placed on board of a vehicle and is dedicated to protection of radio receivers. The max. limit for the radiated emission is between 25 and 49 dBµV/m at 1 m  depending on the severity class, our receiver is protected at 1 m of our equipment. > MIL-STD-461E: this is a military standard. The max. level is between 44 and 64 dBµV/m  possibility of interferences. 38 April 17

39 EMC measurement for electronic systems
Immunity measurements – General measurement set-up Injected level Extraction Failure detection Disturbance generation Harmonic signal Transients Burst Coupling device Coupling network Antennas Wave guide Clamp… 50Ω adapted path Radiated or conducted coupling Equipment / Device under test Immunity requirements verified ? April 17

40 EMC measurement for electronic systems
Immunity measurements – General test procedure for harmonic disturbance Start F = Fmin P = Pmin Increase P Detection mask Without EMI Increase F Wait dwell time Failure or P = Pmax ? F = Fmax ? Save F and P With EMI Failure End April 17

41 EMC measurement for electronic systems
Radiated immunity in (semi-)Anechoic chamber (30 MHz – 1 GHz) Typical max. RI level: Commercial product: 3 – 10 V/m Automotive (ISO ): 25 – 200 V/m Military (MIL-STD461E): 20 – 200 V/m Aeronautics (DO160-D): 8 – 800 V/m (Siepel) Field monitoring Absorbents Signal synthesizer Wide band (calibrated) antenna Device under test Faraday cage (with absorbents: semi-anechoic chamber) 1 m 1 m R = 3 ou 10 m Power amplifier ( > 100 W) 1 m Power supply, DUT control April 17

42 Induced current measurement
EMC measurement for electronic systems Immunity measurements – Bulk current injection (BCI) Signal synthesizer RF disturbance Induced current measurement Power amplifier Induced RF current Directional coupler Failure ? DUT LoadLISN Bus, cable Interface circuit Measurement clamp Microcontroler Injection clamp Faraday cage Usually, the max. current is between 50 mA and 300 mA. April 17

43 EMC measurement for electronic systems
Immunity measurements – Pulse, ESD, bursts, surge… Pulse waveforms and severity levels defined by standards such as IEC x or ISO7637 Ideal ESD waveform at 4 KV (IEC ) (level 2) Ideal Fast transient / burst (IEC ) (level 2) Ipeak = 15 A Vpeak = 1 KV (on 50 Ω) Td= 50 ns Tr = 5 ns Repetition rate = 5 – 100 KHz I30 = 8 A Vpeak = 1 KV (on 50 Ω) I60 = 4 A Tr = 0.8 ns April 17

44 EMC measurement for integrated circuits
Why testing EMC for ICs ? Integrated circuits are often the main cause of disturbances in electronic equipment. In recent years, there has been a strong demand for simple, reliable and standardized measurement methods focusing only on integrated circuits that electronic system designers could use to: Obtain quantitative measure of emission/immunity from ICs establishing a uniform testing environment Qualify the low emission and high immunity performance of circuit. Optimize circuit placement, routing, filtering and decoupling components Evaluate the impact of IC redesign, technology improvement or package modification. April 17

45 EMC measurement for integrated circuits
Why testing EMC for ICs ? Based on pre existing standards, such as: CISPR 25 – Radio disturbance characteristics for the protection of receivers used on board vehicles, boats and on devices – Limits and methods of measurements IEC – Electromagnetic Compatibility (EMC) – Part 4: Testing and measurement techniques ISO part 1 to 7, Road vehicles – Electrical disturbances by narrow band radiated electromagnetic energy – Component test methods Measurement methods for EMC of Ics proposed by IEC: IEC 61967:Integrated circuits -Measurement of electromagnetic emissions, 150 kHz to 1 GHz. IEC 62132: Integrated circuits - Measurement of electromagnetic immunity, 150 kHz to 1 GHz. IEC 62215: Integrated circuits – Measurement of impulse immunity April 17

46 EMC measurement for integrated circuits
International standards for IC emission measurement methods IEC (TEM : 1GHz) (GTEM 18 GHz) IEC (WBFC, 1 GHz) IEC (IC-Stripline, 3/6 GHz) IEC (Near field scan, 1/5GHz) IEC (Magnetic field probe, 1GHz) IEC (1/150 ohm, 1 GHz) IEC (Mode stirred chamber, 1 GHz) Radiated method TEM Cell improvemnt Conducted method Investigation method April 17

47 EMC measurement for integrated circuits
IC Conducted emission VddCore Integrated circuit Icore(t) Digital Core VE/S(t) Vdd osc I/O Iosc(t) Load Oscillator Driver PCB line Vdriver(t) Load Two noise sources: internal activity (power supply noise) and I/O switching (Simultaneous Switching Noise, I/O line excitation) Characterization of transient current and voltage induced by ICs. April 17

48 EMC measurement for integrated circuits
IC Conducted emission - IEC –1 ohm / 150 ohms method Conducted emission is produced by RF current induced by IC activity. The current induced voltage bounces along power distribution network and radiated emission. Vdd RF current PCB IC Decoupling Spectrum analyzer 1 Ω 49 Ω « Local » ground IRF « Global » ground The  « 1 ohm » method aims at measuring the RF current flowing from circuit Vss pin(s) to the ground reference. April 17

49 EMC measurement for integrated circuits
IC Conducted emission - IEC –1 ohm / 150 ohms method I/O switching is a major contributor to conducted emission. They induced voltage fluctuation along power supply and I/O lines. Vdd RF current 51 Ω 120 Ω 6.8 nF Spectrum analyzer 150 Ω matching network VRF VA I/O buffer Decoupling External load PCB The « 150 ohms » method aims at measuring the RF voltage induced at one or several IC output. April 17

50 EMC measurement for integrated circuits
IC current extraction from 1 Ω probe measurement dsPIC33F: measurement in time domain and frequency of the voltage across the 1 Ω probe  proportional to the IC current. April 17

51 EMC measurement for integrated circuits
IC Radiated emission - IEC – TEM cell TEM cell (SAE J1752/3) IC under test 50 ohm Spectrum analyzer Pre-ampli dB Test board Emission spectrum Relation between the voltage measured by the spectrum analyzer and the radiated emission from the circuit April 17

52 Quasi homogeneous field
EMC measurement for integrated circuits TEM cell – EM field inside the waveguide y Tapered transition Tapered transition y Aperture for DUT W E Port1 Port2 50 Ω 50 Ω T septum H z O x Wsept Field repartition: W = 15 cm, T = 9 cm, Wsept = 10 cm, V = 1 V, y = 8 cm TEM propagation mode up to 1 GHz |E/H| = 377 Ω R.J. Spiegel, and al.,“A Method for Calculating Electric and Magnetic Fields in TEM Cells at ELF”, IEEE Trans. on EMC, Nov. 1987 Quasi homogeneous field

53 Appearance of non TEM propag. mode
EMC measurement for integrated circuits TEM cell – Field coupling with a DUT Example: coupling with a 50Ω microstrip line Dimensions of the microstrip: W = 2.5 mm, L = 75 mm, h = 1.6 mm, epsr = 4.5 Port2 VNA 50 Ω load Near end Far end Appearance of non TEM propag. mode 50 Ω load Port1 septum The magnetic field coupling depends of the orientation of the line in the TEM cell. + 20 dB/dec.

54 EMC measurement for integrated circuits
International standards for IC susceptibility measurement methods IEC (BCI, 1 GHz) IEC (DPI : 1 GHz) IEC (TEM - GTEM : 1 / 18GHz) IEC (IC-Stripline, 3/6 GHz) IEC (WBFC, 1 GHz) IEC (LIHA, 10GHz) IEC (Near-field scan, 1/5 GHz) IEC (Mode stirred chamber, 1 GHz) Conducted methods Radiated methods TEM cell improvement Investigation method April 17

55 Radiated disturbances Induced conducted disturbances
EMC measurement for integrated circuits Conducted immunity Applying conducted disturbances directly to IC pin ? Electronic equipment Radiated disturbances Victim circuit Cables PCB Induced conducted disturbances Vs Zs Zc, Td ZL Equivalent Thevenin generator of RF disturbances Cables, PCB lines Input impedance of victim circuit 55 April 17

56 Susceptibility threshold
EMC measurement for integrated circuits Conducted immunity - IEC – Direct Power Injection (DPI) Individual test of each sensitive IC pin. Signal Synthesizer Test on 1 pin Decoupling network Failure detection > 400 Ω Pforw Prefl Directional coupler DPI Capacitor ( 1 – 10 nF) Chip under test Amplifier Oscilloscope Acquisition card Susceptibility threshold April 17

57 Example : DPI test on the power supply of an RF device
EMC measurement for integrated circuits Conducted immunity - IEC – Direct Power Injection (DPI) Example : DPI test on the power supply of an RF device Forward power limit Simple, repeatable, low power measurement IC prequalification test April 17

58 I/O type – protection level
EMC measurement for integrated circuits Conducted immunity - IEC – Direct Power Injection (DPI) Class Fwd Power (dBm - RMS) Voltage (V) (across 50 Ω) I/O type – protection level 1 Low filtering, pin connected to long cable harness (power circuit) 2 20 – 27 3 – 7 Short connections, low filtering (signal conditioning, communication line driver) 3 1 - 2 No direct connection with the environment April 17

59 EMC measurement for integrated circuits
Case study – Starcore EMC testing The Starcore is 16-bit micro-controller used in automotive industry: 16 bit MPU with 16 MHz external quartz, on-chip PLL providing internal 133 MHz operating clock 128 Kb RAM, 3 general purpose ports (A, B, C, 8 bits), 4 analog inputs 12 bits, CAN interface Prepare an EMC test plan: conducted emission (1 /150 Ω) and susceptibility test (DPI) SIGNAL Description VDD Positive supply VSS Logic Ground VDD_OSC Oscillator supply VSS_OSC Oscillator ground PA[0..7] Data port A (programmable drive) PB[0..7] Data port B (programmable drive) PC[0..7] Data port C (programmable drive) external 66MHz data/address ADC In[0..3] 4 analog inputs (12 bit resolution) CAN Tx CAN interface (high power, 1MHz) CAN Rx XTL_1, XTL_2 Quartz oscillator 16MHz CAPA PLL external capacitance RESET Reset microcontroller Conducted emission test: > 1 ohm: on Vss pins to characterize the current returning to gnd from the IC. Can be global (connect Vss and Vss_osc) together, or separate characterization of each Vss pins > 150 ohms: to characterize voltage fluctuations on power supply pins (Vdd_osc, Vdd) and digital I/Os configured as output buffer: if the same I/O model is used for every I/Os of the IC, only one 150 ohm probe can be placed. CAN TX has certainly a different model than PA, PB, PC pin  one test on CAN Tx + one test on a general purpose output. If different I/O drive options are used, the conducted emission tests should be done for the different drive options. > optional: Capa pin because some charge can be provided by the capacitor  circulation of current  noise. Conducted susceptibility test (DPI): > power supply pins (Vdd_osc and Vdd): class 2 or 3 (depending on the connection to the DC source, regulator…) > one digital I/O (PA, PB, PC): class 1 or 2 (if connected by a long PCB track) > one analog input (ADC): class 1 or 2 (if connected by a long PCB track) > CAN Tx and CAN Rx: class 2 (if connected by a long PCB track) > RESET : it is a very sensitive for the application: class 2 (if connected by a long PCB track) > XTL1-XTL2: class 1 April 17


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