Isolation Design for Uncompromised Safety and Reliability.ppt by pptfiles

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									Isolation Products Division                                              Your Imagination, Our Innovation




                              Isolation Design
                               for Reinforced
                                 Safety and
                                 Reliability
                              Avago Optoisolation Products
                                       Nov 2011




Page 1                                 Avago Technologies Confidential
Isolation Products Division                                     Your Imagination, Our Innovation




Safety Isolation is regulated by IEC standards
• High voltage is life threatening.
• Safety isolation is regulated by international standards and
  compliance to standards must be certified.
• Standards are established by experts in the field and based on
  rigorous engineering experiment and test data.
• Equipments connected to high voltages need to comply to
  equipment standards.
• Isolation components used in equipments need to be certified to
  standards required by the equipments.
• IEC 60747-5-5 is a standard ONLY for optocoupler, not for
  alternative isolators, e.g. magnetic and capacitive isolators.




Page 2                        Avago Technologies Confidential
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BASIC and Reinforced Insulation
• Voltage > 30Vac or 60Vdc is defined as hazardous voltage
• 2 level of protection is required between hazardous voltage and
  safe voltage.
• 1st layer is BASIC insulation and 2nd layer is supplementary
  insulation
• Combination of BASIC insulation and supplementary insulation
  is known as Double Insulation.
• If a single layer of insulation has the same insulation property as
  double insulation, this is known as Reinforced insulation.




Page 3                        Avago Technologies Confidential
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Overview of Equipment Safety Standards
 Safety       Scope                                 Construction Requirements for           High Voltage Test Method           Equipments
 Standard                                           Reinforced Insulation                                                      Examples
 IEC60664,    Insulation Coordination For                                                   Impulse, a.c/d.c. hipot,
 UL840        Equipment Within Low Voltages                                                 partial discharge
              (<1000Vac or <1500Vdc) Systems
 IEC61800     Adjustable Speed Electrical Power     Solid Insulation DTI >= 0.75mm          Impulse, a.c/d.c. hipot,           Motor Drives
              Drive Systems                         Thin sheet >= 0.2mm 1 layer             partial discharge
                                                    Thin sheet < 0.2mm; 3 layers
 EN50178      Electronic Equipment for use in                                               Impulse, a.c/d.c. hipot,           Motor Drives
              power installations                                                           partial discharge
 IEC60950-1   Information Technology Equipment      •Solid Insulation > 0.4mm               Impulse, a.c/d.c. hipot            Networking
              Safety                                •> 2 layers for thin sheet insulation                                      Power Supply,
                                                    • Optocoupler                                                              POE, Router
                                                    • Semiconductor Isolator
 IEC60601-1   Medical Electrical Equipment – Part   •Solid Insulation > 0.4mm               Impulse, a.c/d.c. hipot            ECG, Endoscope
              1: General requirements for basic     •> 2 layers for thin sheet insulation
              safety and essential perforamce       •Optocoupler
 IEC61010-1   Safety requirements for electrical    •Solid Insulation > 0.4mm               Impulse, a.c/d.c. hipot            Power Analyzer,
              equipment for measurement,            •> 2 layers for thin sheet insulation                                      Industrial Scope
              control, and laboratory use           •Optocoupler
 UL508        Industrial Control Equipment                                                  Impulse, a.c/d.c. hipot            PLC, Lighting
                                                                                                                               Dimmer
 UL2202       Electrical Vehicle Charging System                                            Impulse, a.c/d.c. hipot            EV Charger


Page 4                                                Avago Technologies Confidential
 Isolation Products Division                                                                                      Your Imagination, Our Innovation




 Overview of Component Safety Standard
Isolation          Norm               Scope                                                    Key Requirements
Devices
Transformer        EN61558            Safety of Transformers and General Requirements          Hipot Test,
                   (VDE0570)                                                                   Specify constructions.
Capacitor          EN 132400          Harmonized system of quality assessment for electronic   Impulse Test: up to 8kV for 250Vac (Y1)
                                      components. Sectional specification. Fixed capacitors    Specify constructions
                                      for electromagnetic interference suppression and
                                      connection to the supply mains (Assessment Level D)
Optocoupler        IEC 60747-5-5      Semiconductor Devices – Discrete Devices – Part 5:       Impulse Test: 10kV
                                      Photocouplers                                            Partial Discharge

Optocoupler        UL1577             Standard for Optical Isolators                           Hipot Test up to 5kVrms 1min


Semiconductor      VDE0884-10 (in     Magnetic Digital Isolator                                Similar to obsolete optocoupler standard
Isolator           draft status)                                                               VDE0884-5.




Status of Optocoupler Standard
IEC 60747-5-5 Official Released in 2007,
DIN EN60747-5-5 Based on IEC 60747-5-5, Officially Released in Nov’2011
IEC 60747-5-2 To be withdrawn and replaced by IEC 60747-5-5 in 2012.
DIN EN 60747-5-2 based on IEC 60747-5-2, to be withdrawn and replaced by DIN EN 60747-5-5 in 2014.
VDE 0884-5 has been replaced by DIN EN 60747-5-2


 Page 5                                                    Avago Technologies Confidential
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Isolation Technology Overview




                    Optocoupler                                          Magnetic or Capacitive Isolators
DTI (Distance through Insulation): 80um to 1000um                                DTI: 8um to 17um
                Number of Layers: 3                                            Number of Layers: 1
  Insulation Material: Polyimide Tape + Silicone                      Insulation Material: SiO2 or Polyimide
        Electric Field Stress: Vbias / 80 um                            Electric Field Stress: Vbias / 8 um




Page 6                                  Avago Technologies Confidential
Isolation Products Division                                                     Your Imagination, Our Innovation



                              Inside Optocoupler




                                                                    Side view
         Zoom side view




Page 7                            Avago Technologies Confidential
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Using Alternative Isolators for Safety Application
• Component safety standard should cover
     • Sample test for insulation quality
     • Production test for manufacturing defect screening
• Safety standard for magnetic and capacitor isolators are NOT available
     • Attempts of setting up the standard has been rejected due to lack of experts participation
     • As a compromise magnetic and capacitive isolators are seeking safety certifications of
       • drafted magnetic standard (VDE 0884-10),
       • optocoupler standard DIN EN 60747-5-2 for BASIC insulation
       • equipment standards, e.g. IEC 60950, IEC 61010 and etc.
• Test compliance should not substitute
     • Understanding of insulation characteristics and aging mechanism,
     • qualification of insulation lifetime,
     • effective manufacturing defects screening




Page 8                                       Avago Technologies Confidential
Isolation Products Division                                                                                               Your Imagination, Our Innovation



Optocoupler Safety Standard IEC 60747-5-5
(This is what Avago optocouplers are certified according to)
Test Type           Test Method            Test Condition                                                                 Passing Criteria

Type Test           Environmental Stress   Rapid Change of Temp : 10cycles, dwell time – 3hrs                             No insulation
(20 Samples)                               Vibration: Axis – 3, 10cycles, amplitude -75mm/98m/s2                          degradation.
                                           Shock : Axis -3, acceleration – 980m/s2

                                                                       60s
                    Transient Test              Viotm
                                                                                                                X 1.875   Partial discharge < 5pC
                                                Vpd,b                                                           X 1.6
                                                Vpd,a

                                                Viorm
                                                                                                10s, PD < 5pC

                                                                     Method a), TYPE Test

                    Surge Test                                                                                            RIO>109W at VIO=500V
                                                                   10kVpeak

                                                                   50us

                                                        1.2us


Routine Test        Partial Discharge           Viotm
                                                                                                                          Partial discharge < 5pC
(100%                                                              1s, PD < 5 pC     X 1.875
                                                Vpd,b
Production)                                     Vpd,a
                                                                                            X 1.6


                                                Viorm




                                                                Method b3), ROUTINE Test




Page 9                                      Avago Technologies Confidential
 Isolation Products Division                                                                               Your Imagination, Our Innovation



Question : Is optocoupler standard applicable to alternative isolators?
     Surge Test per optocoupler Standard IEC 60747-5-5, passing criteria >= 10kV




                Avago Optocoupler         Supplier A Magnetic                        Supplier S RF   Supplier T
                                                                                                     Capacitive


      Avago optocoupler passed 10kV surge test by wide margin.
      Random samples of magnetic isolators barely passed 10kV however failed at 12kV.
      RF and capacitive isolators using SiO2 as isolation failed 8kV and 6 kV respectively.

                                        Answer : NO
 Page 10                                           Avago Technologies Confidential
 Isolation Products Division                                                                                         Your Imagination, Our Innovation



Question : Is optocoupler standard applicable to alternative isolators?
  Partial Discharge Test Capability and Continuous Working Voltage Rating
  Step 1. Select 5 samples of optocouplers, magnetic and                                                                High Voltage and
  capacitive isolators each in same SOIC package with 8mm                                                               High Temperature
  creepage.                                                                                                             Stress Test Setup
  Step 2. For 8mm creepage select 1.6kVrms as continuous
  working voltage as solid insulation is good for 200Vrms/mm.
  Step 3. Perform partial discharge on all units at 3kVrms
  (1.875X1.6kVrms), indicating partial discharge free for
  1.6kVrms.
  Step 4. Perform 1.6kVrms stress under 125^C. Measure time
  to failure based on continuous leakage monitoring.

   Isolation         Insulation      DTI (mm)        Partial           Working            Aging Mechanism / Life     Life time        Time to Failure
  Technology                                     Discharge Test        Voltage             Expectancy Prediction     Prediction       under 1.6kVrms
                                                    Voltage          Capability per               Model                                   Bias at
                                                                       standard                                                         Ta=125^C
  Optocoupler    Polyimide Tape +        0.4        3kVrms            1.6kVrms               Partial Discharge     No Degradation       > 4000 hrs
                     Silicone
   Magnetic         Polyimide          0.017        3kVrms              1.6kVrms              Space Charge             80 hrs               12 hrs
                                                                                              Degradation /
                                                                                          Thermodynamic Model
   Capacitive          SiO2            0.008        3kVrms              1.6kVrms            TDDB / E-Model            2500 hrs              21 hrs


   1. Optocoupler lifetime is consistent with partial discharge result.
   2. For magnetic and capacitive isolators partial discharge predicts far optimistic lifetime than actual results. It is not a
   suitable test for isolators using thin layer insulation.
                                               Answer : NO
 Page 11                                                Avago Technologies Confidential
      Isolation Products Division                                                                                     Your Imagination, Our Innovation



Is equipment standard, e.g. IEC 60950, applicable to alternative isolators?
  •       Internal construction of semiconductor isolators, e.g. magnetic and capacitive isolators, DO NOT MEET
          equipment requirements for reinforced insulation.

              IEC 60950 Requirements                             Semiconductor Isolators
              Solid Insulation DTI >= 0.4mm                      Min DTI : 0.008 mm or 0.017mm
              Or >=2 layers for thin sheet insulation            1 Layer



  2. Sample and production test detect leakage current at high voltage, potentially destructive to thin layer insulation.

          Test Type          IEC 60950 Requirements                                           Example
          Type Test          1.6X of Max Transient Voltage of Power Installation              4800Vrms for 420Vpeak rated mains
          Routine Test       Max Transient Voltage of Power Installation                      3000Vrms for 420Vpeak rated mains

          •       Need non-destructive production test to screen manufacturing defects in thin layer insulation.


  3. Test compliance to equipment standard is NOT sufficient for reliable safety insulation due to
        • thin layer insulation and
        • lack of defect screening methodology for continuous working voltage.


      Page 12                                               Avago Technologies Confidential
 Isolation Products Division                                              Your Imagination, Our Innovation



Conclusion on IEC Standards
  • Safety standard for optocoupler is well established and proven effective in
    predicting optocoupler’s lifetime.
  • Optocoupler standard, IEC 60747-5-5, does not apply to magnetic and capacitive
    isolators, due to differences in construction and insulation material. High working
    voltage life stress has shown partial discharge predicting overly optimistic for
    lifetime of magnetic and capacitive isolators.
  • Equipment safety standard is based on assumptions of solid insulation or
    multilayer thin sheet insulation. Ultra thin layer insulation used by magnetic and
    capacitive isolators introduces large electric field stress compared to conventional
    insulation. Its aging and defect screening needs to be studied for safe and reliable
    application.
  • Test compliance to optocoupler and equipment standards can be obtained by
    magnetic and capacitive isolators. However it is ultimately designer’s and
    manufacturer’s responsibility to ensure safety and reliability of the equipment by
    applying the right insulation.




 Page 13                              Avago Technologies Confidential
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          Why are we still better then alternative technologies?




Page 14                        Avago Technologies Confidential
 Isolation Products Division                                                                                        Your Imagination, Our Innovation



Avago Technology offers the best isolation technology with reinforced reliability

 Proven Quality and Reliability Track Record
 §    Avago is the number one supplier for photo IC                           §     Avago has more than 35 years of experience
      optocoupler in the world, with billions of units operating in                 manufacturing Optocouplers for industrial and military
      the field                                                                     applications
 §    Millions of units have been shipped and are operating in
      the field for major renewable energy and car makers WW



 Technology Leader
 §         Advance LED technology with best in class performance §                  Largest optocoupler portfolio
           over lifetime and at high temperature                 §                  Won 2008 Global Optocouplers Company of the Year
 §         High EMI and common mode noise immunity                                  Award by Frost & Sullivan
 §         Robust and reliable galvanic isolation technology




 Best Customer Support
 §         International component safety certifications                    §       Technical response center
            §   IEC 60747-5-5                                               §       Excellent delivery and lead time track record
            §   UL 1577                                                     §       Worldwide sales and application support
            §   CSA Component Notice 5



 Page 15                                                   Avago Technologies Confidential
 Isolation Products Division                                                                Your Imagination, Our Innovation


Optocoupler provides added advantages in harsh industrial and automotive environment.
                                                              Avago ACPL-M72T Optocoupler
• Common Mode Rejection



                                                                                            dV/dt = 45kV/us




  Vcm=1kV, freq=12.5MHz
                                                              Supplier S XX8441B RF




                                                                                               dV/dt = -4kV/us




 Page 16                            Avago Technologies Confidential
 Isolation Products Division                                                                         Your Imagination, Our Innovation


Optocoupler provides added advantages in harsh industrial and automotive environment.

• EMI Immunity

                                                                                  CH1: Vo1              CH3: 1060A/us
                                                                                  CH2: Vo2



                                                                                  CH3: ESD Current




                                                                                   CH1: Vo1

                                                                                   CH2: Vo2
                                                                                                     CH3: 130A/us



                                                 Supplier T
      Avago Optocoupler   Supplier A Magnetic    Capacitive

 Page 17                                        Avago Technologies Confidential
 Isolation Products Division                                                                                    Your Imagination, Our Innovation


Optocoupler provides added advantages in harsh industrial and automotive environment.

• EMI Immunity (MM)                                                                                      Communication OK.



                                                                                                             EMI noise current: 15A




                                                                                   Avago Optocoupler --- No missing bits seen at 15A
                                                                                              of loop current nearby.




                                                                                                Communication Error.




                                                                                                           EMI noise current: 2.8A



                                                                                    Magnetic Isolator --- Missing bits seen at 2.8A of
            Avago Optocoupler   Supplier A Magnetic                                               loop current nearby.

 Page 18                                         Avago Technologies Confidential
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      Optocoupler provides added advantages in harsh industrial and automotive environment.

        • Radiated Emission


                                                                                                                      Avago ACPL-
                                                                                                                      M72T -
                                                                                                                      Optocoupler


                                                                                                                       34.5dBuV
      Input Freq: 1MHz, 1-ch ON




                                                                                                                       Supplier S
                                                                                                                       XX8441B – RF
                                                                                                                       Isolator




                                                                                                                      45.2dBuV

Avago Optocoupler Supplier A Magnetic   Supplier S RF   Supplier T
                                                        Capacitive

        Page 19                                                      Avago Technologies Confidential
Isolation Products Division                                           Your Imagination, Our Innovation




            Negligible LED Degradation
    LED for ACPL-x6xL 10MBd ultra low power digital optocouplers




                              Mean data at varying IF
Page 20                             Avago Technologies Confidential

								
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