I set out to design a SPI -> 4x Pt100 interface based on the TI ADS124* ADC series. I made the attached schematic, BOM and board file (in EAGLE format). Any comments or ideas as to what I could've missed?
My design goals:
* Get as much accuracy out of the ADC as possible while using 3-wire Pt100s
=> matched trace lengths for all analog inputs
=> low-tolerance resistors (especially Rbias)
=> low-noise linear voltage regulator
* Try to adhere to circuit design best practices (split analog/digital part, etc)
Questions:
* Are there obvious improvements to the PCB layout?
* Is ESD protection necessary, or is the built-in stuff enough?
Board:
Front:
Back:
I tried to upload the .brd, but it wouldn't let me.