0-5v used with upscale thermocouple burnout

[CMS]

I use a type of signal conditioning unit for thermocouples and RTDS that provides an upscale output in case of sensor burnout.  As the burnout signal output is above 5v.  I pressume the ADC will only return 1024 anyway?  Will this 5 volt plus voltage damage the ADC?

T100MD888 used in this application

Thanks

[support]

What is the burn-out voltage like? The ADC can take temporary overvoltage as long as it is not too high. You can protect the ADC input by using a diode and connect the diode anode to the ADC input and cathode to +5V. This way it will clamp the input voltage to the ADC to not more than 5.7V and as long as the diode use has very low reverse leakage current it will not load the ADC as long as the input to the ADC is below 5V.

[CMS]

Thanks for that.   I believe the upscale voltage is around 5.3-5.5 volts.  
It probably wont be much help anyway as anything over 5volts will show as 4096???

Cheers

[support]

That's right. Above 5V it will be shown as 4092 (4096 is full scale. The maximum value is always full scale - 1 LSB)

If it is maximum of only 5.3 to 5.5V there is no worry of damaging the ADC and protected diode is not required.