I am currently building a data logging device for monitoring battery packs which contain 8 Lithium cells. The device will periodically log the voltages of all 8 cells, as well as log temperatures collected from 3 thermistors. My device has an STM32L series microcontroller.
As of now I am trying to figure out what the input circuit for the ADC should be. Due to the high power nature of the system, and it containing two large industrial motors which are subject to varying loading, I am assuming the battery pack would be subjected to high voltage and current spikes. I will be taking taps from each cell and connecting it to my device.
In terms of protection, I have done some research and found I should probably be looking into TVS and clamping diodes as protection means. The input range that needs to be measured is 0-32V. I have guesstimated the following circuit:
The TVS diode is SMAJ33A (http://www.littelfuse.com/~/media/electronics/datasheets/tvs_diodes/littelfuse_tvs_diode_smaj_datasheet.pdf.pdf) with a standoff voltage of 33V, and maximum clamping voltage of 53.3V @ 7.5A (Ipp). I am not sure how to select the TVS diode (or if I even need one!), so I would really appreciate any advice on this. For the clamping diode part, I am following ADC input protection?. I have selected Bat54S dual Schottky barrier diodes. This is to hopefully provide over voltage protection.
Do you think my choice of circuit protection is sufficient for this application? Any advice would be really appreciated. Thanks!