SLVAEW6 December 2020 TPS2661
- Trademarks
- 1Introduction
- 2Protection Required for Current Inputs in Analog Input Modules
- 3Typical Discrete Circuit for Protection of Current Input
-
4TPS26610 for Analog Current Loop
Protection
- 4.1 Current Input Protection with TPS26610
- 4.2 Accurate Current Limiting with TPS26610
- 4.3 Leakage Current of TPS26610 and Current Measurement Accuracy
- 4.4 Protection from Mis-wiring to Field Power Supplies
- 4.5 Heating and Temperature Rise with TPS26610
- 4.6 Reduction in PCB Size with TPS26610 for Current Input Protection
- 5Conclusion
4.2 Accurate Current Limiting with TPS26610
TPS26610 has an accurate limiting for protection with 249? burden resistor from mis-wiring faults to field supplies with voltage up-to Vs supply of the device.
Figure 4-2 provides the variation of current limit of TPS26610 with temperature.
Figure 4-2 Current Limit with
TPS26610With accurate current limiting, the power dissipation in burden is reduced and numbers of burden resistors are reduced. Table 4-1 summarizes the number of 0805 (125 mW) burden resistors for different values of RBurden.
Table 4-1 Reduced Power Dissipation in
Burden Resistor with TPS26610
| ILIM(max) | RBurden (Ω) | Power Dissipated in RBurden (mW) | Number of 0805 (125mW) burden resistors required in Parallel |
|---|---|---|---|
| 35 mA | 249 | 305 | 3 |
| 35 mA | 100 | 122.5 | 1 |
| 35 mA | 49 | 61.25 | 1 |