AnsweredAssumed Answered

I need help for programming a AD8555

Question asked by Yoontts on Mar 13, 2015
Latest reply on Mar 17, 2015 by JGunao

Hi, I'm a college student in Seoul, Korea.  Thanks for reading my post. I speak english well....so, I hope you understand what I mean and want to know..please......

 

Nowadays I study about Amplifier AD8555 for Wheatstone bridge with strain gauge. AD8555 is very nice for amplification and DAC.

 

but, when I program the signal for the operation of AD8555, It's weird that the operation of GAIN between Offset.

 

In the datasheet of AD8555, THEORY OF OPERATION, equation 1 and 2 show us how to calculate the code for operation we need.

 

It means that code of GAIN and Offset is independent. But when I change the code of first and second GAIN, the Output of AD8555 is

 

also changed. I think if we do not change the code of Offset, Voltage offset of output does not change either. But, it's wrong.

 

So, I wonder that CODES OF GAIN and OFFSET are operating independently?? Did I have a wrong code?

 

I attach my code for AD8555. I use dsPIC for MCU.

 

I hope you understand what I mean, and want to get I need.

 

Sincerely yours. Appreciate for reading my words.

Attachments

Outcomes