Protect Current-Sense Amplifiers from Negative Overvoltage

Abstract: Current-sense amplifiers normally operate well above ground, but a fault condition can drive the sense inputs below ground, damaging the device by drawing excessive current through the ESD-protection diodes. This circuit protects a particular high-side current-sense amplifier (MAX4080) by connecting PMOS blocking transistors in series with each input.
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Maxim > Design support > App notes > Circuit Protection > APP 4837

Keywords: current-sense amplifiers, negative fault voltage, ESD-protection diodes

Feb 09, 2011
APPLICATION NOTE4837
Protect Current-Sense Amplifiers from Negative Overvoltage
By:Arpit Mehta, Strategic Applications Engineer
Prashanth Holenarsipur

Abstract:Current-sense amplifiers normally operate well above ground, but a fault condition can drive the sense inputs below
ground, damaging the device by drawing excessive current through the ESD-protection diodes. This circuit protects a particular high-
side current-sense