A Comparison Between MIL-STD and Commercial EMC Requirements Part 2. By Vincent W. Greb President, EMC Integrity, Inc.

Transcription

1 A Comparison Between MIL-STD and Commercial EMC Requirements Part 2 By Vincent W. Greb President, EMC Integrity, Inc.

2 OVERVIEW Compare and contrast military (i.e., MIL-STD) and commercial EMC immunity test requirements and test methods Commercial requirements will be limited to the standard requirements for Information Technology Equipment (ITE) Military requirements will focus on requirements for Space Systems This will be a top-level treatment, as a comprehensive study would be a one-week short course Commercial-off-the-shelf (COTS) movement of 1990 s

3 MILITARY EMC EMC requirements for military applications have existed since the 1940s. The evolution of military/aerospace EMC requirements has resulted in numerous standards encompassing for different applications/environments. Most military (DoD) procurements require compliance with MIL-STD-461x, the first version of MIL-STD-461 was published in This document has been revised and/or amended many times since that time. Although the current version of MIL-STD-461 is the F version, this presentation will focus on the E version, published on 20 August 1999.

4 MIL-STD REQUIREMENTS MATRIX* Equipment and Subsytems Installed In, On or Launched From the Following Platforms or Installations Requirement Applicability RS103 RS101 RE103 RE102 RE101 CS116 CS115 CS114 CS109 CS105 CS104 CS103 CS101 CE106 CE102 CE101 RS105 Surface Ships A L A S S S A L A A A L A A L Submarines A A L A S S S L A L A A A L A A L Aircraft, Army, Including Flight Line A A L A S S S A A A A A L A A L Aircraft, Navy L A L A S S S A A A L A L L A L Aircraft, Air Force A L A S S S A A A A L A Space Systems, Including Launch Vehicles A L A S S S A A A A L A Ground, Army A L A S S S A A A A L L A Ground, Navy A L A S S S A A A A L A A L Ground, Air Force A L A S S S A A A A L A *Ref. MIL-STD-461E, 20 August 1999, p. 27.

5 OVERVIEW OF MIL-STD TESTS* Requirement CE101 CE102 CE106 CS101 CS103 CS104 CS105 CS109 CS114 CS115 CS116 RE101 RE102 RE103 RS101 RS103 RS105 Description Conducted Emissions, Power Leads, 30 Hz to 10 khz Conducted Emissions, Power Leads, 10 khz to 10 MHz Conducted Emissions, Antenna Terminal, 10 khz to 40 GHz Conducted Susceptibility, Power Leads, 30 Hz to 150 khz Conducted Susceptibility, Antenna Port, Intermodulation, 15 khz to 10 GHz Conducted Susceptibility, Antenna Port, Rejection of Undesired Signals, 30 Hz to 20 GHz Conducted Susceptibility, Antenna Port, Cross-Modulation, 30 Hz to 20 GHz Conducted Susceptibility, Structure Current, 60 Hz to 100 khz Conducted Susceptibility, Bulk Cable Injection, 10 khz to 200 MHz Conducted Susceptibility, Bulk Cable Injection, Impulse Excitation Conducted Susceptibility, Damped Sinusoidal Transients, Cables and Power Leads, 10 khz to 100 MHz Radiated Emissions, Magnetic Field, 30 Hz to 100 khz Radiated Emissions, Electric Field, 10 khz to 18 GHz Radiated Emissions, Antenna Spurious and Harmonic Outputs, 10 khz to 40 GHz Radiated Susceptibility, Magnetic Field, 30 Hz to 100 khz Radiated Susceptibility, Electric Field, 2 MHz to 40 GHz Radiated Susceptibility, Transient Electromagnetic Field *Ref. MIL-STD-461E, 20 August 1999, p. 26.

6 OVERVIEW OF COMMERCIAL EMC IMMUNITY TESTS (ITE) Requirement EN 55024: A1: A2: 2003 IEC Description (Product Family Standard) Information Technology Equipment Immunity Characteristics Limits and Methods of Measurement Testing and measurement techniques Electrostatic discharge immunity test IEC IEC Testing and measurement techniques Radiated, radio-frequency, electromagnetic field immunity test Testing and measurement techniques Electrical fast transient/burst immunity test IEC IEC IEC Testing and measurement techniques Surge immunity test Testing and measurement techniques Immunity to conducted disturbances, induced by radiofrequency fields Testing and measurement techniques - Power frequency magnetic field immunity test IEC Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests

7 IMMUNITY (SUSCEPTIBILITY) COMPARISON Military (461E) No 461E equivalent RS103 CS114 CS115 CS116 (loosely) RS101 (Note 1) No 461E equivalent CS101 Commercial (EN 55024) Electrostatic discharge Radiated RF immunity Conducted RF immunity Electrical fast transient Surge immunity Power frequency H-field immunity Voltage dips and interruptions No commercial equivalent Note 1: RS101 is not required for the space environment

8 Electrostatic Discharge Testing Test levels specified by 55024; test method defined in No 461 equivalent although MIL-STD-1541A does outline an indirect discharge test. Human body model defined by -4-2 is 150 pf capacitor and a 330 ohm resistor. Standard provides for direct (air and contact) discharge as well as indirect discharge testing. Test levels: +/- 4 kv contact; +/- 8 kv air. Contact applicable to conductive surfaces. Air applicable to non-conductive surfaces.

9 IEC Contact Waveform *Ref. IEC , Edition 2.0, , p. 13.

10 Setup for ESD Test (Table Top) *Ref. IEC , Edition 2.0, , p. 17.

11 Comparison: Radiated RF Immunity Parameter Test Method Frequency Range Field Strength Step Size Dwell Time Modulation Notable differences MIL-STD-461E RS103 2 MHz to 40 GHz 20 V/m See table (next slide) 3 seconds (min) 1 khz Pulse Mod. Real-time feedback EN IEC MHz to 1 GHz 3 V/m 1% (for entire range) 3 seconds (min) 1 khz AM sine Playback generated from 16-point field uniformity calibration

12 Step Sizes Defined by MIL-STD-461E Frequency Range 30 Hz to 1 MHz 1 MHz to 30 MHz 30 MHz to 1 GHz 1 GHz to 8 GHz 8 GHz to 40 GHz Step Size (%) 5% 1% 0.5% 0.1% 0.05%

13 *Ref. MIL-STD-461E, 20 August 1999, p Test Setup for RS103

14 Field Strength for 461E *Ref. MIL-STD-461E, 20 August 1999, p. 127.

15 Test Setup for Radiated RF Immunity *Ref. IEC , Edition 3.1, , p. 49.

16 Uniform Field of *Ref. IEC , Edition 3.1, , p. 53.

17 Comparison of Field Strengths Field Strength (V/m) Frequency (MHz) 461E - Space IEC for IT

18 Comparison: Conducted RF Immunity Parameter Test Method Frequency Range Injected Level Step Size Modulation Notable differences MIL-STD-461E CS khz to 200 MHz See Curve #3 See table (Slide #12) 1 khz Pulse Mod. Bulk current injection (BCI) method Playback generated from calibration into 50 ohm system Run to playback, limit on current EN IEC khz to 80 MHz 3 Vrms 1% (for entire range) 1 khz AM sine CDN, EM Clamp, then BCI method Playback generated from cal. into 150 ohm system Run to playback, allowed to limit on current

19 461E Injection Levels *Ref. MIL-STD-461E, 20 August 1999, p. 68

20 CS114 Pre-test Calibration *Ref. MIL-STD-461E, 20 August 1999, p. 70

21 CS114 Cal Schematic Injection Point 50 ohm 50 ohm (1) Notes 1. Spectrum Analyzer Input 2. Injection level specified as current through 50 ohms. 3. Injection level set as specified current across 50 ohms (S/A), as measured by forward power port of directional coupler. 4. Limit on current (whichever is less stringent).

22 CS114 Test Setup *Ref. MIL-STD-461E, 20 August 1999, p. 71

23 CI Calibration General Setup Injection Point 100 ohm 100 ohm 50 ohm 50 ohm (1) Notes 1. Spectrum Analyzer Input 2. Injection level specified as U o / Current limit set as U o / 150.

24 Conducted RF Immunity Test Setup *Ref. IEC , Edition 3.0, , p. 23

25 Comparison of Injection Levels Amplitude (dbua) Frequency (MHz) 461E - Curve #3 IEC for IT

26 Comparison: CS115 to EFT/B Parameter Test Method Waveform Injection Type Test Level Notable differences MIL-STD-461E CS115 Repetitive Pulse Inductive 5 Amps (peak) BCI injection method 30 Hz repetition rate Setup similar to CS114 EN IEC Repetitive Pulse Train Capacitive 1 kv (O.C.V) AC 0.5 kv (O.C.V) I/O Capacitive injection method Pulse train

27 CS115 Test Setup *Ref. MIL-STD-461E, 20 August 1999, p. 77

28 CS115 Waveform *Ref. MIL-STD-461E, 20 August 1999, p. 75

29 IEC Test Setup *Ref. IEC , 2 nd Edition, , p. 45

30 IEC Pulse Train *Ref. IEC , 2 nd Edition, , p. 41

31 IEC Waveform *Ref. IEC , 2 nd Edition, , p. 42

32 Comparison: CS116 to Surge Parameter Test Method Waveform Injection Type Test Level Notable differences MIL-STD-461E CS116 Damped Sine - discrete frequencies from 10 khz to 100 MHz Inductive 5 Amps (peak) AF (10 A for Army & Navy) BCI injection method 1 pps repetition rate Setup similar to CS114 EN IEC Quasi-triangular pulse Capacitive + 2 kv AC (CM) + 1 kv AC (DM) Capacitive injection method 1 pulse per minute

33 CS116 Test Setup *Ref. MIL-STD-461E, 20 August 1999, p. 84

34 CS116 Waveform *Ref. MIL-STD-461E, 20 August 1999, p. 81

35 IEC Injection (DM) *Ref. IEC , 2 nd Edition, , p. 37

36 IEC Injection (CM) *Ref. IEC , 2 nd Edition, , p. 38

37 IEC Waveform *Ref. IEC , 2 nd Edition, , p. 29

38 IEC Overview Power frequency magnetic field immunity Designed to demonstrate immunity of products to low frequency (50 & 60 Hz) magnetic field Specifies methods for both immersion and proximity (immersion preferred). Current version is 2 nd Edition, MIL-STD-461E equivalent is RS101 which is a proximity method test covering the frequency range from 30 Hz to 100 khz.

39 IEC Test Setup *Ref. IEC , 2 nd Edition, , p. 19

40 IEC Overview Voltage dips, short interruptions and voltage variations Applies to electronic equipment not exceeding 16 Amps per phase Designed to demonstrate robustness when unit under test experiences fluctuations in AC input voltage Based on IEC Current version is 2 nd Edition, MIL-STD equivalent would be MIL-STD-704

41 Example of Variation *Ref. IEC , 2 nd Edition, , p. 19

42 CS101 Overview Audio (i.e., low) frequency conducted susceptibility test Applicable to DC (and AC) power inputs Frequency range typically 30 Hz to 150 khz Inductively coupled Swept frequency or step and dwell Level on voltage; limit on power No commercial equivalent

43 CS101 Pre-test Calibration Signal Generator LF Amplifier Coupling Transformer 0.5 ohm Oscillosope

44 CS101 Test Setup

45 Conclusions Not a lot of similarity between commercial and MIL-STD immunity. MIL-STD typically impinges higher amplitude across a broader frequency range MIL-STD for space environment clearly designed for space. Commercial IT immunity clearly defined for earth-bound environment.