Other Parts Discussed in Thread: TINA-TI
Tool/software: TINA-TI or Spice Models
I am working on an IN-Amp design for measuring the temperature of a Pt1000 NTD Thermistor. Using a single sided supply of 3V3 and having the NTD in a voltage divider (Vcc->5600 -> VIn -> 15k||NTD->GND). Vref is tied to GND, as is Vin-.
What I am seeing in both TinaTI and using LTSpice with the model I imported is that the Gain set by Rg does not accurately represent the output voltage.
For instance, I have a model with a Vin of 412.47mV, and Rg=25k, the output voltage is only 749.73mV, not 2V as expected with a gain of 5.
Has anyone else had this issue?
