INA333 EMG Instrumentation Amplifier

Hassan,

Which version of Pspice/OrCad do you use? Is it 15.7 and above?

Herman

Hi Herman,

Well yeah its above 15.7 , it is the 16.0 version. I cant really figure out how to make it in OrCAD ., Im even finding it hard to find the footprints/dimensions for the INA333 IC

Kind regards,

Hassan. 

I am not an expert in PCB usage of OrCad, but if I understand correctly basically you requested

a test bench of INA333 in OrCad/Pspice so that you can run simulation on it. Am I right?

Or do you actually need the footprint/dimensions of INA333 so that you can draw layout on OrCad PCB tools?

If it is the former, we can provide it. If it is the latter, I have to find somebody that knows the answer to this.

Yeah thats exactly what I requested , the former one. The latter issue I mentioned regarding the footprints/dimensions of INA333, is also some thing I need help with. It would be really kind of you if you are able to help.

I worked on the test benches today and will be posting them most likely tomorrow.

Regarding the footprint/dimensions..

We usually put the dimension/footprint for PCB layout purposes on our datasheet.

For instance if you go into our datasheet of INA333:  http://focus.ti.com/lit/ds/symlink/ina333.pdf

page 19 to 24.. it discusses about the details of dimension/footprint.

I am not sure if the answer above meets your need. If you need something more specific,

can you tell us what specific information you need?

Oh okay I was trying understand it from pages 19 to 24 earlier today. I found it a bit confusing, but I am trying to figure out, since am a bit new to OrCAD 16.0.

I will work on it the next day as well, so ill tell you if i may need anything more specific on that. And thankyou very much regarding the test benches, hope to receive it from you soon =)

thanks again Herman!

Regards,

Hassan.

Sorry for the late reply. i just read ur message. I'll follow your instructions and let you know. Thank you so much Herman, you are so kind.

Cheers, Hassan.

yeah .. it was all running perfectly fine..

Now,the "PCB Symbols/Footprints" are not there at INA333 webpage on www.ti.com. Also, I have been analysing the Datasheet of INA333 but its not too clear on the dimensions of the component.

Are you using the MSOP or SON package? Drawings for both package types are in the product folder. I'll have to check and see if we already have footprints for those packages in OrCAD format. Pretty sure we don't have a schematic symbol for the INA333, but if you have the footprint you can build your own symbol and connect the two - and if we don't have the footprint, you can put one together from the drawings we have on the website.

I have made a footprint using the dimensions given at page number 20 (of the data sheet of INA333) in OrCAD Layout

Great! That's the drawing for the MSOP package.

Let us know if there's anything further we can do.

OOhh yeah it is MSOP =) Thanks bro i'll let you know!

Can anybody tell me if there is any way I can get an output voltage of 3.3 V at Vout with a "Single Supply" of 3.6V at V+ , and an Input "Vin +" of 10 to 15 mV (coming from an EMG sensor). The input signal can be made to be a sinusoidal signal of 10mV.

The input signal has to be analog.. please note that.

To answer your question correctly, I need more information. Yes, with a 3.6V V+, the output can swing to 3.3V - but that depends upon the load. What is the load that the INA is driving?

You say 10-15mV signal is on Vin+; what is on Vin-? What is V-? (I assume it's zero since you said it's "single supply").

I also need to know what your common mode voltage is so we can make sure that it's not going to cause any internal nodes to saturate).

Can you post your proposed schematic around the INA333?

the ina333 is taking its input from 

I attached the file which Icurrently have made in the above post. Its a "TINA schematics diagram" of the circuit which i have made up till now , and it is dual-supply based. It has "Vin -" grounded, and "V-" and "V+"  can be attached to +/-1.8V each.

What i basically need is to make it single supply, with a single battery of 3.6V being used at supply only. the input signal would be the same probably, because im basically testing it to be compatible with an EMG sensor, which would give 10mV on average to the "Vin+" of this INA333 instrumentation amplifier. 

Ask me if u want more information. cheers.

Regards,

Hassan.

You might want to review this discussion in the Precision Amplifier forum. It's from someone trying to do something similar.

I hesitate to give you a recommended circuit without knowing all the details about your sensor. Contact impedances and offsets can severely limit the amount of gain you can put at this stage. If reading the linked article doesn't answer your question, then I'd suggest getting all the details on your sensor together and posting a question in the Precision Amplifiers forum and see what the apps guys there have to recommend.