INA225: IR Tester Design

Hi Purvik,

Which reference design did you simulate? Also, do you mind supplying me with the Multisim file so I can verify the design? 

Best,
Mohamed 

Hi,

Please find the attached file and Links.

Schematic-TIDA-00440MB.PDFhttps://drive.google.com/file/d/1BgybQOux-RkAjGXUzSO0qoWRcZWEOe0f/view?usp=sharing

Hello Purvik,

There are a few issues I see.  First the INA2256 cannot drive a 1µF capacitor directly.  (C5), C1 should be after R2 and R3.  GNDs on U2 should all be the same.  Please make sure all the grounds are correct as this will cause issues. The PDF does not match the simulation schematic GND  This is one of the most important parts otherwise you will not correct potentials and cause shorts or connection that will give large errors.

Hello,

Firstly this is not INA2556 it's INA255.

Please find the attached link here with changes but it's not work there is a no change in results.

drive.google.com/.../view

Also if you have Tina based simulation file you can share. I also using a Tina Software.

Also if you have Tina based simulation file you can share. I also using a Tina Software.

Hello Purvik,

Sorry for typo.  I will take a look at your circuit but in the mean time there are simulations in the https://www.ti.com/tool/TIDA-00440 site.  At the bottom of the page there are 3 simulation files.  I have placed them below for quick access.

Hi,

I have tested your give designs. But now I want to increase voltage upto 1000VDC and Measurement Range 200 Mohm.

So how to do that ? What type of changes required ?

Hi,

Ignore Pervious comment.

I have tested your give designs. But now I want to increase voltage up to 1000VDC and Measurement Range 2000 Mohm.

So how to do that ? What type of changes required ?

Hell Purvik,

I will need to look into this design as it was not mine.  Since most of the design is moving with the high voltage I will look at what components are connected between high voltage and low voltage to make sure they can handle the 1000V.

Regards,

Javier

Hello Javier,

So can you do that for me because I don't have experience for high voltage.

here I want to use same components as given in the application note. But in application note only 500 VDC and 100 Mohm mention so i need to extend this range. So, Can I use INA225 and AMC1200 ? 

Hello,

I am requesting to you please update.

Hello Purvik,

The issue is what everything is referenced to and when there is isolation that the devices meet the requirements for voltage.  For example the schematic has 3 different GND and each one is referenced to a different node.  The GND1 is the reference to INA225 in the diagram so all the voltages are reference to that for the INA225.  I myself have not done high voltage testing but understand the keys for being able to isolate the different reference points.

Javier