Help to using AD620...

[magina]

ad620

Hi everybody...
I want to make Temperature Control and use Thermocouple type K as sensor...
As instrument amplifier I choose AD620...
I've read and try as datasheet example but still not work...
If you have use AD620,,can you help me how to use it pin to pin...

Please help me...

 

[FvM]

ad620 application

Figure 42b from data sheet should work for you.

P.S.: AD623 may be preferable if you have single supply and are attending rail-to-rail operation.

 

[magina]

ad620 circuits

Thank You for replly..
I've tried it but still not work..
I use Rg= ≈22k,, So G=≈3
±Vs = 10 Volt and Ref to GND
±IN = 1 Volt
Based on the output must 3 volt but in I just get 0.5 volt...
I try to increase the Input to 1.5 or 2 Volt but still not change,, the output ≈0.5.
I measure the output with meter,, one in Out and others in pin 5 (ref)
Can you tell me why this can happen??
Can you give me example more specific pin to pin how to use AD620...

Thank You

 

[FvM]

ad620 thermocouple

I always used AD620 in circuits similar to datasheet application. I don't see a particular reason why it should fail. Do you have a bipolar supply with Ref connected to mid voltage? Did you also have a connection between mid voltage (GND) and inputs to assure defined common mode voltage? (As suggested in the datasheet application circuits)

 

[magina]

thermocouple ad620

Yes i used bipolar voltage with mid voltage (gnd) is connected to ref and input...
Or maybe the problem at AD620 (maybe it's broken or something)...

 

[magina]

thermocouple amplifier ad620

Thank you for your offer but I think my time isn't enough to buy others and I'm from Indonesia...
But thank you for your attention...

And maybe I'll design Instrument Amplifier by using LM324,,,
can some help me show some design with this IC...
Thank You so much...

 

[ameyakale]

Hey, I'm using AD620 for MQ3 gas sensor, It is working properly for 10K POT but as I give sensor input it directly jumps to 5V.
What might be problem?

 

[karesz]

Hi Magina,
Sorry, but a discret built InstrAmp vs a really good IC: it isnt a good idea, but you must know it...
I see yet on w*w.mikrocontroller.net/topic/51971 that somebody has had similar problems with a bridge if the bridges supplying was not exactly same as of the Ad620. Is it your case too?
K.