We are working on PoC based on LTC3108-1. We wish add a LED for visual monitoring, LTC3108 is not able to supply a suffisient current to drive the LED.
Could we use C2 input for drive an external Mosfet (low Qg) ?
I'm not expert of this product but this is my take as I tried to study it. I'm not sure if you can use C2 for any other purpose than for the gate drive of the internal FET. About the LED for visual monitoring, this may not be ideal too. This product is designed for very low power application. Power consumption for LED may defeat the goal of conserving power as possible.
I recommend you connect to a local ADI FAE to help. Or if you can give me your company, project info, Estimate Annual Usage, I can help you connect to one.