SLVAF40 July   2021 TPS2661

 

  1.   Trademarks
  2. 1Introduction
  3. 2Discrete Solution With PTC
  4. 3TPS26610 Advantages to a Typical Solution
    1. 3.1 BOM and Size Reduction
    2. 3.2 Burden Resistor and Power Dissipation
    3. 3.3 Voltage Drop
    4. 3.4 Signal Good
    5. 3.5 Additional TPS26610 Features
      1. 3.5.1 Miswiring
      2. 3.5.2 Surge
      3. 3.5.3 Current-Loop Test During Installation (Unpowered)
      4. 3.5.4 High Accuracy For Current Measurements
  5. 4Conclusion

2 Discrete Solution With PTC

Figure 2-1 shows a typical discrete solution based on a positive temperature coefficient device (PTC) used to protect the current input of an analog input module.


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Figure 2-1 Discrete Solution With PTC

The downsides of a typical solution are:

  • System size due to the BOM in terms of size and count of the components (see Figure 2-1)
  • Constraint of high-power dissipation of the burden resistor in overcurrent condition reduces the choice of selection
  • Temperature dependency of the front end (mainly from PTC)
  • Higher voltage drop at the analog input limits the length of the current loop
  • Lack of status (overcurrent versus normal operation)