SLVAEW6 December   2020 TPS2661

 

  1.   Trademarks
  2. 1Introduction
  3. 2Protection Required for Current Inputs in Analog Input Modules
    1. 2.1 Over-Current Protection from Miswiring to Field Power Supplies
    2. 2.2 Over-Voltage Protection from Miswiring to Field Power Supplies
  4. 3Typical Discrete Circuit for Protection of Current Input
    1. 3.1 Protection Provided by Discrete Circuit
      1. 3.1.1 Over-Current Protection with Discrete Circuit
      2. 3.1.2 Over-voltage Protection with Discrete Circuit
    2. 3.2 Heating and Temperature Rise with Discrete Circuit
    3. 3.3 Reverse Leakage Current of Zener Diodes and Current Measurement Accuracy
  5. 4TPS26610 for Analog Current Loop Protection
    1. 4.1 Current Input Protection with TPS26610
    2. 4.2 Accurate Current Limiting with TPS26610
    3. 4.3 Leakage Current of TPS26610 and Current Measurement Accuracy
    4. 4.4 Protection from Mis-wiring to Field Power Supplies
    5. 4.5 Heating and Temperature Rise with TPS26610
    6. 4.6 Reduction in PCB Size with TPS26610 for Current Input Protection
  6. 5Conclusion

4.3 Leakage Current of TPS26610 and Current Measurement Accuracy

TPS26610 device only takes a total leakage current less than 20nA from IN and OUT pins and this contributes to an error less than 0.0001% in current measurements of 20mA.Figure 4-3 provides the sum of leakage current from IN and OUT pins of TPS26610 with a voltage of 5V across burden resistor. With TPS26610, it is possible to use a burden resistor of resistance 50 to 249Ω and achieve higher ENOB and lower noise for current measurements.

GUID-20201210-CA0I-ZCZ8-T7NT-23TR0HJNL46D-low.svg Figure 4-3 Leakage Current of TPS26610