SBOA595A May   2024  – October 2024 AMC1202 , INA169 , TMCS1108

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Current Sensing
  5. 2Key Challenges of Current Sensing for Negative Power Supply
  6. 3Proposed Current Sensing Designs for Negative Power Supply
    1. 3.1 Hall Current Sensor
    2. 3.2 Current Sensing Based Isolated Amplifier
    3. 3.3 Current Sensing Based Isolated ADC
    4. 3.4 Current Sensing Based Difference Amplifier
  7. 4Summary
  8. 5References
  9. 6Revision History

4 Summary

This application note introduced four methods to monitor load current for a negative power supply. Every method has benefits. In an actual application, the designer can select any method for a specific application under constraint of performance, safety, PCB area, cost, and so on. Table 4-1 shows the different design features for designer reference and the designer can then select the best design for a specific application.

Table 4-1 Comparison Table Between Four Current Sensing Methods
ItemHall SensorIsolated amplifierIsolated ADCINA145/6
PrecisionGoodBetterBestBetter
Common voltage range70 to approximately 400V800V to approximately 2000V500V to approximately 1500V±30V or ±100V
Design difficultyEasyMiddleMiddle

Easy

PackageMiddleLargeLargestSmallest
CostLowHigh CostHighest CostLowest