Hi,
I'am developping a Current to Voltage convertor so that i can read a sensor current from 0-20mA.
The design is standard, a 250 resistor, an OpAmp and then the ADC, so far so good.
At 20mA the Voltage over the resistor is 5V and this is also the maximum voltage the ADC can measure.
But what happens when the current becomes 27mA because of a faulty sensor, then the voltage over the resistor is 6,75V.
This is killing the ADC, how can i protect this ?
Frank.