A circuit providing solution with
discrete elements consist of TVS diode, Zener diodes and PTC. During a miswiring event,
TVS diode provides protection from surge pulses, PTC is required for over-current
protection while Back-to-Back Zener diodes are required for overvoltage protection and
limiting the power dissipation in Burden Resistor. For comparison of TPS2661x with
discrete solution, see
Enabling Smarter, Integrated Protection for 4-20mA Current Loops
with eFuses.