INA126: INA126P or other instrumentation amplifier for single supply amplifier of a signal between 0V and 10mV

Concerning previous post:

This is the circuit for INA126

and this is the circuit for INA122

This instead is INA122 with one of the inputs tied to ground:

and it seems ity is not linear as I need

Hello Etantonio,

Thank you for your post. The INA126 has an input common mode voltage range which swings beyond the negative rail. On a 5V single supply, the input common mode range is 0 to 3.4V.

However, the INA122 doesn't have this level of swing. It swings 3.75V from either rail. You really can't operate on a 5V single supply with this device for this reason. However, +/-5V would work:

Your input is 0 to 10mV. What is the expected output? I can help see if we can come up with a solution.

-Tamara

Hi Tamara,

thanks for your answer,

My input is 0 to 10mV and the corresponding output have to be ideally 0 to 3.3V. The supply is a 5V single supply.

This circuit is almost ok, only a reduced dinamic (starting at 1V instead of 0V)

but the real implementation is not tailored to this simulation.

It is available a TI single supply instrumentation amplifier that simply amplify a positive voltage?

Thanks,

Antonio

Thanks Tamara,

this seems really better than use INA126 as single supply amplifier.

I just modified some values to use the full range of the ADC (0 to 3.3V)

Only problem for me is that INA326 is not available in PDIP package so, at the moment, I need to use an adapter.

Thanks,

Antonio

Hi Antonio,

My apologies, I shared a schematic that was to 3V out. Looks like you were able to easily modify it to 3.3V, though.

We have a DIP ADAPTER EVM that allows you to convert a VSSOP to PDIP: http://www.ti.com/tool/DIP-ADAPTER-EVM

Would that be helpful for you?

-Tamara

Thanks Tamara for all your help.

Antonio