I'm currently designing a product using the BCM20737S module and it requires that it be powered from a lithium ion battery.
The battery produces up to 4.2V which exceeds the maximum value for VBAT from the datasheet (3.63V).
I was wondering what the most efficient way to step down the battery voltage would be.
As far as I understand it there is an LDO in the SIP that reduces the battery voltage down to the 1.2V used by the core and radio. In that case it seems like the best option would be to use an efficient buck converter to step the voltage down to a level close to 1.2V to minimise the current draw from the battery. If so what voltage should I set as the output of the buck regulator?
Would it be better for me to use the BCM20737L in this case?
Sounds like an idea if you do not have a choice. Below is the STM LDO part number.