Part Number: MSP432P4111
Hello,
We are considering to use MSP432P4111 in our design. One of our requirement is to have low cost and low power consuming backup for RTC. Currently we are using button cell for MSP432's internal RTC backup and would prefer something on similar lines. Apparently MSP432 do not have RTC battery backup option. So we have considered following options:
1. Using external RTC IC
- Obvious disadvantage of cost, area consumption
2. Muxing with second battery as mentioned in linked thread (https://e2e.ti.com/support/microcontrollers/msp430/f/166/p/710992/2628282?tisearch=e2e-sitesearch&keymatch=MSP432%25252520RTC%25252520Battery#2628282.
- Lesser cost but still mux IC is required
- Current consumption and complexity of operations during switching from Primary to Secondary source
So following are our questions regarding internal RTC backup:
1. How much second method is feasible with button cell as backup battery? Is there any other side effects during switching?
2. Is there any example/ application note available which had implemented method 2?
3. Our design is at initial stage hence if there is any alternate part number with battery backed RTC then please suggest the same.
4. Is there any other method to achieve expected performance?
Regards,
Tanmay
