Hi there,
I have been working on this for a few days now and am kind of stuck, so I have decided to reach out to the community to see if anyone can shed some light on my doubts regarding the following circuit.
The circuit I have drawn is based on the reference design for the CS5530 provided by Cirrus Logic.
I aim to design a loadcell (Wheatstone bridge) weigh indicator capable of reading 40000 intervals, where the transducer allows it).
Although it will not be used to read 40000 intervals, I would like to set that as the target for the project.
I will list all my doubts, even though I do not expect all of them to be answered, to avoid creating multiple repetitive posts.
My doubts are as follows:
1. How can I supply VD+ and VA+? Can they be the same 3V3 or 5V rail coming from an LDO?
2. From the schematic, it is possible to see that Vref from the LT1019 is 2.5V; would it not be better to use the 5V version of the LT1019 to create a 5V excitation for the bridge?
3. Can VD- and VA- be tied to the same ground plane?
So far, this is what I have been able to draw:
In the first schematic, I have kept the digital voltage separate from the analog voltage as per the Cirrus schematic, while in the second schematic, all the grounds are tied to the same ground plane, or at least that is what I was trying to achieve.
I am new to this, so I apologise if something is missing or unclear; any help will be greatly appreciated!
Edit:
I am not able to attach the images inline; I hope it will still be clear.