SBOA536 December   2021 INA240

 

  1.   Trademarks
  2. 1Introduction
  3. 2Grounding in DC Circuits
  4. 3Grounding in Isolated Current Sensing Applications
  5. 4Working Principle of Non-isolated Current Sense Amplifiers
    1. 4.1 Single or Multi-stage Difference Amplifier
    2. 4.2 Current Feedback
    3. 4.3 Switched Capacitor
    4. 4.4 Input Stage and Input Bias Current
  6. 5Grounding in Non-isolated Current-Sensing Applications
  7. 6Level Shifting for High-Voltage Current-Sensing Applications
  8. 7Grounding in Motor Current-Sensing Applications
    1. 7.1 Common-Mode Voltage of Motor Current Sense Amplifiers
    2. 7.2 Directionality of Motor Current-Sense Amplifiers
    3. 7.3 PCB Design for High-Performance Motor Drive
  9. 8Summary
  10. 9References

4.1 Single or Multi-stage Difference Amplifier

This topology resembles the classical diff amp, designed as either single stage or a cascade of two. The total gain equals to the product of the gains of all stages. The CMRR of this topology depends on the matching of resistors. Some form of trimming is necessary to achieve high CMRR. Figure 4-1 shows a block diagram of a CSA based on diff amp topology.

Figure 4-1 Single-Stage Diff Amp Based CSA