AD620 reference circuit

Hi KDN,

What is it you are trying to do? Can I know what is your specific application so that I can give a reference circuit that suits to your needs?

Generally, an instrumentation amplifier is a device that accepts a differential input and provides a single-ended output with respect to a reference terminal. It amplifies the difference of the input signal on the non-inverting(+IN) and inverting input(-IN). Ideally, your output voltage would be Vout = G((+Vin)–(-Vin)) + Vref

The gain of AD620 can be set using a single external resistor RG, you need to connect this resistor across the RG pins of the device. In addition to that, the gain of AD620 and the value of RG can be computed using the formula below. Table 5 of the AD620 datasheet shows the standard resistor values for RG for each corresponding calculated gain. Note that for G=1, RG pins are unconnected.

You may also try to read this book, A Designer's Guide to Instrumentation Amplifiers. It is a very good reference in studying instrumentation amplifiers.

Let me know if you any more questions.

Regards,

Jay

I want to use this Instrumentation Amplifiers to measure signal from LVDT sensor . Can  you provide me reference design for it.

I am also searching for device which can generate sinwave with output 10V rms and 1A rms.

This both IC are too much costly, do  you have any other alternative. 

Hi KDN,

How about this reference design?

http://www.analog.com/media/en/reference-design-documentation/reference-designs/CN0371.pdf

Regards,

Gustavo

KDN,

  Have you looked at the AD598 or AD698?  They are designed for LVDT interface.

Harry

KDN,

Keep in mind that the AD620 came out in 1991, and if you have to redesign due to obsolescence,

it will cost you money.  Look at some of the newer InAmps, such as AD8422, AD8421, AD8426.

  Also, the 598 and 698 do math.

Are you going to do this in software?  How fast does your system require?

Harry

look at my circuit , I am getting only positive value

What if I want reference voltage zero, do I have to short 5 number pin with ground

ok it's start working , their is some non-linearity due to diode , how can I remove it?

Thanks Jay,

Now I need to work on power supply of LVDT ,

Can I connect ground of my electronic circuit or oscillator with ground of coil, will negative voltage of sin wave affect my circuit?