Monolithic Power Systems, Inc. · NASDAQ:MPWR

Monolithic Power Systems — Technical Presentation (June 2021)

24 slides from Monolithic Power Systems's technical presentation, Jun 15, 2021

  1. Slide 1: Simple Approach to Isolated High-Current Measurement Webinar

    Simple Approach to Isolated High- Current Measurement Webinar June 15th, 2021 Presenter: Ted Smith

  2. Slide 2: Agenda

    Agenda Current Sensing System Level Perspective Overview Achieving Cost Effective Isolation Differential Hall Principle Solving Thermal Challenges Managing Noise While Maximizing Bandwidth Easy Implementation Techniques

  3. Slide 3: Inverter as an example

    Inverter as an example | mrS

  4. Slide 4: 3 Phase Inverter Low Side Current Sensing

    3 Phase Inverter Low Side Current Sensing - No isolation needed - Load current is detected, but individual phase currents unknown - Phase short circuit goes undetected Load

  5. Slide 5: 3 Phase Inverter Low Side Current Sensing

    3 Phase Inverter Low Side Current Sensing - No isolation needed - Phase currents can be reconstructed in microcontroller with some difficulty - Phase short circuit goes undetected Load

  6. Slide 6: 3 Phase Inverter Phase Current Sensing

    3 Phase Inverter Phase Current Sensing - Phase currents are known - Load shorts are detected - Isolation required Load

  7. Slide 7: 3 Phase Inverter Isolation

    3 Phase Inverter Isolation High Voltage Logic Voltage FET Driver Isolated Current Sensor Load Microcontroller 6

  8. Slide 8: Current Sensing Design Options: Current Transformers

    Current Sensing Design Options Current Transformers PRO • Accurate • Isolation included CON • AC only • Large Footprint (XYZ) • Expensive

  9. Slide 9: Current Sensing Design Options: Shunt + Amplifier

    Current Sensing Design Options Shunt + Amplifier PRO • Simple V = iR CON • Multiple Components/Large Footprint • Isolated Amplifier Required • Large footprint (shunt + iso amp + Kelvin connections) • Power dissipation

  10. Slide 10: Current Sensing Design Options: Hall Sensor

    Current Sensing Design Options PRO • Complete isolated current sensor in SOIC MPS (Hall Sensor Based) • Single IC – easy design in • Smallest solution footprint • Senses up to 50 A • 0.9 mΩ primary – power efficient • Cost Effective CON • Sensing limited to 50 A primary current • Max current limited

  11. Slide 11: Isolation in Detail

    Isolation in Detail Working Voltage • Lifetime continuous operating voltage • Determines limit to prevent long-term degradation of insulation • Viorm = 250 VRMS Peak Isolation • One time overvoltage for example, electrical spike • Viso = 2200 Vpeak (min) Design Perspective • Able to operate continuo

  12. Slide 12: Technical Detail About Differential Hall-Based Sensing

    Technical Detail About Differential Hall-Based Sensing Primary Conductor B1 B2 Ampere’s Law: B ∝ I Sensing Sensing Point 1 Point 2 Bmeasure = 𝐵1 − 𝐵2

  13. Slide 13: Differential Sensing Results in Stray Field Immunity

    Differential Sensing Results in Stray Field Immunity Btarget • Adjacent Load Currents Can Cause Stray Magnetic Fields B1 B2 • Differential Sensing Results Stray Field Sensing Sensing Immunity Point 1 Point 2 • Output Voltage Proportional to Measured Field Difference: Stray Field B1 – B2 = 0 Stray Fi

  14. Slide 14: Solving Thermal Challenges

    Solving Thermal Challenges • Current Sensor • Lower Internal Resistor is Better: 0.9mΩ • Example: 30 Arms Load • P = 0.9 mΩ * 30 A * 30 A = 0.81 W • Die temp change < 35°

  15. Slide 15: Bandwidth Control for ADC Interface

    Bandwidth Control for ADC Interface • Pin Configurable Bandwidth Range: 1 kHz … 100 kHz • Reduction of Sensors Bandwidth • Simple Single Small Passive Capacitor • Designs which don‘t require full bandwidth can benefit from lower noise • Examples: • Full bandwidth - 63 mA noise • 20 kHz switching – s

  16. Slide 16: System Interfacing with Ratiometric Output

    System Interfacing with Ratiometric Output MCS180x • Analog Ratiometric Signals • No extra external reference MCS180x • Covers AC & DC Currents • 0 A defined at VCC/2 MCS180x • Bandwidth up to 100 kHz

  17. Slide 17: Isolated Current Sensing Board Level Solution

    Isolated Current Sensing Board Level Solution Ipmax = 5 A, 10 A, 20 A, 30 A, 40 A, or 50 A

  18. Slide 18: Isolated Current Sensing Board Level Solution

    Isolated Current Sensing Board Level Solution Ipmax = 5 A, 10 A, 20 A, 30 A, 40 A, or 50 A

  19. Slide 19: Isolated Current Sensing Board Level Solution

    Isolated Current Sensing Board Level Solution Ipmax = 5 A, 10 A, 20 A, 30 A, 40 A, or 50 A

  20. Slide 20: Isolated Current Sensing Board Level Solution

    Isolated Current Sensing Board Level Solution Ipmax = 5 A, 10 A, 20 A, 30 A, 40 A, or 50 A

  21. Slide 21: Isolated Current Sensing Board Level Solution

    Isolated Current Sensing Board Level Solution Ipmax = 5 A, 10 A, 20 A, 30 A, 40 A, or 50 A

  22. Slide 22: Cost Effective Isolated Current Sensing

    Cost Effective Isolated Current Sensing  Single IC Solution  Standard SOIC-8  Smallest Solution Footprint  Integrated True Galvanic Isolation

  23. Slide 23: Get Started with Evaluation Boards

    Get Started with Evaluation Boards Part Supply Current Options Accuracy Isolation Number (Vcc) MCS1800 3.3V ±12.5A, ±25A 3% 1000V MCS1801 5V MCS1802 3.3V ±5, ±10, ±20, ±30, ±40, ±50A 2.5% 2200V MCS1803 5V • Visit https://www.monolithicpower.com/en/products/sensors/current- sensors.html • Datasheets

  24. Slide 24: Thank You – Q&A

    Thank You – Q&A For more information, contact: [email protected] Check out our Sensor Solutions brochure at MonolithicPower.com

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