What is the correct way to power a Boron 2G/3G over the pin header from a DC input without LiPo battery?
There are two input options according to datasheet and schematics:
- VUSB Pin
- Li+ Pin
For powering over USB (or VUSB pin), the datasheet states
For powering the Boron 2G/3G version, you’ll either need a USB port that is able support 2A current, or have the LiPo battery plugged in when powering over USB.
I found out this is only half of the truth as the PMIC limits the current input to 500mA per default on the Boron. Without setting this limit to a higher value, a 2A USB/5V supply is useless and the modem will restart caused by voltage drops in high current situations. See https://docs.particle.io/reference/device-os/firmware/boron/#setinputcurrentlimit- for adjusting the input current limit.
@rickkas7 Please have a look if the PMIC hint should be added to the datasheet as using a powerful USB supply alone won’t work. Without reconfiguring the PMIC the modem (not the Boron itself) will restart occasionally (can be only once a day) depending on cellular signal conditions but work most of the time. This is very hard to debug.
- What is prefered? Powering via VBUS/5V with increased input current limit or powering via Li+/4.2V?
- What input current limit should be set? Maximum? Boron 2G/3G peak current is listed as 1800mA, so a limit of 2000mA should be enough?
- When powering via Li+, what is the best voltage? 4.2V?
Related posts, but not answering my questions: