Electronic – Signal Conditioning using Opamp -Need Help

operational-amplifier

I need help in designing signal conditioning circuit using op amp.

I have my sensor out put as 0.6V for 0 deg Celsius and 1.6V at 100 deg Celsius.

So I need to level convert it to 0-5V range for an adc.

So I identified gain as 5 AND OFFSET Voltage as -3V.

Please help me to design an circuit using as differential amplifier.

Best Answer

If you just fed the ADC with the range 0.6V to 1.6V corresponding to 0ºC to 100ºC, you'd have a range of 1V going into a 5V ADC. If the ADC is 10 bit then you'd have approximately 200 least significant bits change for a 100ºC change in temperature.

That, is a resolution of 0.5ºC and, if you could average 10 measurements this would give you 0.05ºC resolution (I'm assuming here that noise would likely give you 1 or 2 bits of variation in the measurement i.e. you'd be implementing a form of dithering).

The question then remains, how much resolution do you require to justify adding an op-amp circuit?