Hi,
Can I connect a 3.7V Li ion battery to the dongle VBUS keeping the SB1 and SB2 configurations as default?

Would this 3.7V applied to IC's VBUS pin cause any issue?
Hi,
Can I connect a 3.7V Li ion battery to the dongle VBUS keeping the SB1 and SB2 configurations as default?

Would this 3.7V applied to IC's VBUS pin cause any issue?
It should be fine applying 3.7V to the VBUS pin. There will flow some current in the 20 uA range (if I remember correctly) into the VBUS pin, so for low power designs it's recommended to not power VBUS unless the USB peripheral is in use.
Please have a look at the absolute ratings in the PS: https://infocenter.nordicsemi.com/topic/ps_nrf52840/abs_max_ratings.html?cp=4_0_0_8
| Note | Min. | Max. | Unit | |
|---|---|---|---|---|
| Supply voltages | ||||
| VDD | -0.3 | +3.9 | V | |
| VDDH | -0.3 | +5.8 | V | |
| VBUS | -0.3 | +5.8 | V | |
| VSS | 0 | V | ||
It should be fine applying 3.7V to the VBUS pin. There will flow some current in the 20 uA range (if I remember correctly) into the VBUS pin, so for low power designs it's recommended to not power VBUS unless the USB peripheral is in use.
Please have a look at the absolute ratings in the PS: https://infocenter.nordicsemi.com/topic/ps_nrf52840/abs_max_ratings.html?cp=4_0_0_8
| Note | Min. | Max. | Unit | |
|---|---|---|---|---|
| Supply voltages | ||||
| VDD | -0.3 | +3.9 | V | |
| VDDH | -0.3 | +5.8 | V | |
| VBUS | -0.3 | +5.8 | V | |
| VSS | 0 | V | ||