INA333 Precision Amplifier

Hi Muralidhar,

yes, the INA333 can work properly with a single supply. Looks like a REF pin issue. Can you show your TINA-TI file?

Kai

Hi Muralidhar,

Enclosed is an example using single voltage rail at 5V. You need to watch for the input common mode Voltage Vcm and Vref voltage, which you may be able to consult with our Analog Engineer Calculator, see the link and Vcm vs. Vout linear relationship below. 

INA333 Single Vrail 01282022.TSC

https://www.ti.com/tool/ANALOG-ENGINEER-CALC

Please pay attention to Vref and Vcm, where the calculator will generate the minimum and maximum differential input signals per the IA configuration. 

If you have additional questions, please let us know. 

Best,

Raymond

Thanks for the response.

REF pin is grounded(also superimposed with Vcc/2 as mentioned in Application note)  for simulation purpose. Actually I wanted to use it for Cold Junction Compensation. Also ensured the output is positive valued by adding DC to input Sine wave. The output gain/the waveforms were spurious. But as soon as tied the -Vcc pin to -5V it works fine as expected. 

Hence I wanted a confirmation on real implementation whether it works with Single Positive supply of 5V, -Vcc grounded.

Thanks for your kind response and the suggested design.

Actually I want to use the INA333 for Thermocouple signal Amplification, with REF pin tied for Cold junction compensation voltage from either a PT100 or LM35. AD623 from Analog devices does that job with a Single Rail voltage of 5V.  

But I thought INA333 has finer offset Voltage characteristics and the Input bias current of 0.2nA compared to 25nA for AD623. But skeptical if I would require Dual Power supply.

It would be great if you could suggest me with a "J-type Thermocouple process module from TI" as a low cost solution.  With Single rail voltage supply for measuring temperatures above 0degC.

Hi Muralidhar,

tiduba5.pdf

And see section 7.

Kai

Hi Muralidhar,

Kai has attached the application note and I captured the image below. Yes, J-type TC (T-type TC has good linearity at low T) will be good for measuring low temperature range above 0C, and you are able to purchase the sensor readily or make your own TC (with a right TC material wires). 

If you have additional questions, please let us know. 

Best,

Raymond

Thanks for the Design Note. Will try out and revert to you for any concerns.

Thanks for all your support.