Slide 1: Mastering Magnetic Sensing: Reducing Environmental Errors through Differential Techniques
Mastering Magnetic Sensing: Reducing Environmental Errors through Differential Techniques November 2024 Session 1 will Begin at 8 AM PST | 11 AM EST | 5 PM CET rev 20180504
Slide 2: Agenda
Agenda Magnetic Sensing Basics Accuracy in Magnetic Sensing Sources of Interference Differential Sensing Case Studies / Examples Q&A
Slide 3: Accuracy in Magnetic Sensing
Accuracy in Magnetic Sensing Systematic • Can be Calibrated Random • Can be Filtered External Influence • Shield / Shunt / Use Differential Technique
Slide 4: Systematic Error Sources
Systematic Error Sources 1. Integral Non-Linearity (INL) 2. Magnetic Misalignment with Sensor (Position Sensing) 3. Latency Latency Error Comp A MA600 Latency 10µs 0µs At 30k RPM 1.8° 0°
Slide 5: Random Error Sources
Random Error Sources Noise: • Resolution captures impact from noise. • Noise can be reduced by filtering, but this reduces sensor bandwidth. Challenges: • Determining of the sensor’s real resolution. • Understanding the relationship between resolution and BW.
Slide 6: External Magnetic Field Effect
External Magnetic Field Effect BRESULT The target field points to a direction indicating the angle (Θ). The interference field is introduced, and BINTERFERENCE BTARGET the worst-case scenario is when BINTERFERENCE is orthogonal to BTARGET. α The result is a vector addition of Θ BINTERFERENCE with BT
Slide 7: Field Strength Examples
Field Strength Examples The amplitude of the interfering field depends on a few different factors: • Permanent magnet size, material, and shape • Current density in a nearby conductor • Distance from the interference source to the sensor element Neodymium Ferrite Current-Carrying Conductor Distance
Slide 8: Deflection in Degrees
Deflection in Degrees Neodymium Ferrite Current-Carrying Conductor Distance (mm) d=5 d = 10mm d = 20mm d = 5mm d = 10mm d = 20mm I = 30A I = 50A I = 100A 1 73 79 81 47 58 63 11 18 34 10 5 26 60 2 9 29 1 2 4 20 1 6 27 0 2 9 1 1 2 50 0 0 3 0 0 1 0 0 1
Slide 9: Methods of Shunting External Fields
Methods of Shunting External Fields
Slide 10: MPS's Differential Hall-Based Sensing
MPS’s Differential Hall-Based Sensing Primary Conductor B1 B2 Ampere’s Law: B ∝ I Sensing Sensing Point 1 Point 2
Slide 11: Differential Position Sensing
Differential Position Sensing
Slide 12: Gradient Immunity
Gradient Immunity Primary Primary Conductor Conductor B2 B2 Sensing Sensing Point 1 Sensing Point 2 Point 3 Bmeasure = 2𝐵2 − 𝐵1 − 𝐵3
Slide 13: Automotive: ASIL-D Electronic Power Steering (EPS)
Automotive: ASIL-D Electronic Power Steering (EPS) Motion Control and Position Sensing • Application: Electronic Power Steering (EPS) • Features/Benefits: o Wide Operating Temp Range: -40°C to +150°C o Available in AEC-Q100 Grade 0/1 o ASIL-D Solution: • MAQ79010FS Recommended Products 12-Bit Automo
Slide 14: Example Application – 3 Phase Current Sensing
Example Application – 3 Phase Current Sensing Industrial Inverter • Application: Motor Drive, UPS, Energy Generation • Requirements: o Wide Operating Temp Range: -40°C to +125°C o Isolation from Bus Voltage o High Accuracy MCS(Q)1810/12 • Up to ±100ARMS • Configurable OCD (1µs Response Time) • Zer
Slide 15: Thank You
Thank You For more information, contact: sensors@monolithicpower.com Check out our Sensor Solutions brochure at MonolithicPower.com
Slide 16: Thank You
Thank You ted.smith@monolithicpower.com rev 20180504