Hello,
I am using a LMP90100 for an RTD that I have hooked up. Originally, I used the dev board with a 3 wire configuration to test and get everything working and it worked great! Now, I've built my own circuit using a 4 wire configuration shown http://www.ti.com/lit/an/snaa195b/snaa195b.pdf and my readings are off quite a bit.
I'm using the equation given on that same page: DOUT = [ RTD * Gain * 2n-1] / RREF
Is this the correct equation to use? should it be (2^n)-1? Making it (2^n)-1 gets me a much more reasonable answer but it's still off by 30 ohms.
My gain is x1, my RREF is 1000 ohms, and the DOUT I'm reading is about 930,000.
Any help or suggestions are appreciated. Thanks
