Sigma Delta Non-Linear | Cypress Semiconductor
Sigma Delta Non-Linear
I am having some issues with non-linear and inconsistent readings off the Sigma Delta converter.
My circuit uses a resistor ladder to attenuate a high DC voltage. That is buffered with an INA217 amplifier. The readings off the amplfier measure in a near linear fashion.
I am having a problem with the converter. It always reads a few milliviolts below what my meter reads. This variation changes with different voltage readings, especially over a large range.
The amplifier circuit is pretty linear, so it is safe to say the problem is the converter.
I read about a similar problem on another thread regarding analog routing and the voltage reference. I have the converter set:
Internal 1.024V reference.
16 bits at 48ksps.
What is going on?