ADA4255
Recommended for New Designs
The ADA4255 is a precision programmable gain instrumentation amplifier (PGIA) with integrated bipolar charge pumps. With its integrated charge pumps, the...
Datasheet
ADA4255 on Analog.com
Dear
I am using the ADA4255 for my analog front end and I noticed some strange behavior on the system thus I have some questions around the component that are not addressed in the datasheet. Talking about datasheet maybe is good to add the chopping frequency on the spec table in the next revision.
My first question is about the zero drift technique used, does the part only use chopping or also auto-zero technique?
Further, I noticed when I feed a sinewave above 60kHz there is a low frequency artifact (around 4kHz) appearing. I suspect that this has to do with the modulation of the signal. Is that a possibility?
I am sharing with you a screenshot where I am feeding a 100kHz signal into the PGA and getting a 4.58kHz frequency artifact. How would you explain that?
Any help is welcome,
Thank you ,
Chris
Hi Gladion,
Hi Gladion,
Below is the schematic side part of ADA4255. While testing the internal MUX is connected to the IN1. P200 and P201 are fed with the input signal from from an Analog Discovery 3. The scope measurements are on the ADC+/- nets which are directly connected to the AD7768. Vcom is sourced by an ADR4525C.
Let me know if there is something more that you need.
Thank you,
C
