SDAA488 August   2026 AMC0106M05 , AMC0106M25

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1System Introduction
  5. 2Inline Current Sense Device Options
    1. 2.1 Common-Mode Voltage Versus Working Voltage
    2. 2.2 Device Architecture Comparison
      1. 2.2.1 INA241: Non-Isolated Analog Amplifier with Inherent PWM Rejection
      2. 2.2.2 AMC0106: High CMRR Functionally Isolated Delta-Sigma Modulator
    3. 2.3 Performance Benefits Analysis
      1. 2.3.1 Accuracy and Precision
      2. 2.3.2 Noise Immunity
      3. 2.3.3 Size
      4. 2.3.4 Design Considerations
  6. 3Summary
  7. 4References

Abstract

This application note compares two shunt-based, in-phase current sensing designs for three-phase motor control inverters operated from 24V to 100V DC bus voltages: the AMC0106M05 and AMC0106M25 functionally isolated delta-sigma modulators and the INA241A non-isolated current sense amplifier with enhanced PWM rejection. The AMC0106M05 supports a ±50mV and the AMC0106M25 a ±250mV linear input range; the INA241A operates over a -5V to 110V common-mode input range. Typical applications are battery-operated drones, servo drives, and collaborative or humanoid robots powered from sub-60V supplies. Both devices are shown to achieve sub-1% measurement accuracy over the full industrial temperature range, meeting the requirements of precision motor control.

Key trade-offs between the two architectures are examined across resolution, noise immunity, propagation delay, and MCU interface requirements. The AMC0106Mxx dual-ground architecture is shown to provide inherent PWM switching noise immunity without blanking periods, achieving greater than 12-bit ENOB through oversampling with a Sinc3 filter at OSR32–128, at the cost of a dedicated high-side supply and an MCU with sigma-delta filter channels. The INA241A is shown to achieve 9 to 11-bit ENOB with a 0.25µs propagation delay at 1MHz bandwidth using a switched-capacitor PWM rejection filter, requiring only an external ADC and voltage reference. Both designs offer small total sizes, making these designs excellent choices for space-constrained motor control designs.