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ADS131M06: ADC Input Protection using Schottky diodes

Adla
Prodigy 80 points
Part Number: ADS131M06

Hi,

I am using ADS131M06 in one of my projects. If fault conditions occur I want to protect the ADC inputs from overvoltages.  So to clamp overvoltages I want to follow a common approach of using Schottky diodes as shown in the image.   

But in 8.3.1 section of ADS131M06IPBS datasheet it is given that " Consequently, shunt diodes between the inputs and AGND cannot be used to clamp excessive negative input voltages." Does this mean that I cannot use the external Schottky diodes configuration( as shown in the image) to clamp the overvoltages? 

 Your reply would be much appreciated.

  • 0
    TI__Guru* 94335 points

    Adla,


    The way you have it drawn should be fine as long as you have a -1.5V supply that can source the current. The diodes are used to shunt currents from an over-voltage event to the supplies.

    The text in section 8.3.1 was intended to discuss shunt diodes inside the device. Normally, we would use diodes to shunt current to the ground. However, with the negative charge pump, the internal diode cannot shunt current to the charge pump voltage.


    Joseph Wu

  • 0 in reply to Joseph Wu
    Prodigy 80 points

    Thank you Joseph wu