I am designing a wearable sensor that has two small 95mAh Li-Po batteries that can be charged using a Qi charger.
I selected the BQ51051 chip for this and I have been struggling with an issue regarding no voltage output from the chip.
The coil I am using is:
https://www.mouser.fi/ProductDetail/Wurth-Elektronik/760308101303?qs=%252B7BPNfeNhvUftm5Jfca3kA%3D%3D
I have also tried these coils:
https://www.mouser.fi/ProductDetail/Wurth-Elektronik/760308101103?qs=08RTzaJQxIrlNtbUKB%2Fexg%3D%3D
https://www.mouser.fi/ProductDetail/Wurth-Elektronik/760308101214?qs=SUJESEQH53AiltUeJALBqQ%3D%3D
I have a finished PCB ready and the chip is on the board.
When I place the coil on a Qi charger, the charger activates normally. I have tried this with multiple chargers and all of them activate ok.
However, when I measure the voltage output from the chip, it remains zero.
This happens regardless of battery connected or not.
I have tested with one battery and both connected, same result.
Here is my schematic:
Maybe I have R5 or R3 wrong, or not enough capacitance next to C29?
Thank you!
