I'm a DFAE in Japan. Our customer develops BMS with LTC6813. I receive questions from him as follows. Could you please let me know the answers?
Q1. When V+ become below +16V, what would LTC6813 happen?
Q2. Under below +16V condition, is it OK to continue to supply +5V to VREG?
A1: As mentioned in the datasheet, range for V+ is from 16-90V. Behavior of IC would be unpredictable below 16V and we don't recommend to operate it in that range.
A2 It is okay to supply +5V on Vreg. but this will keep the iso-SPI/SPI comm woke-up and you will have higher current consumption in sleep state.