I want to let nRF9160 communicate through UART with 3.3V logic level, but the logic level is originally 1.8V.
I have been reading nRF91_DK_User_Guide_v07.pdf, but I'm not really clear.
Any help?
I want to let nRF9160 communicate through UART with 3.3V logic level, but the logic level is originally 1.8V.
I have been reading nRF91_DK_User_Guide_v07.pdf, but I'm not really clear.
Any help?
Hi yusuke217,
You can set the VDD voltage to 1.8 V (default) or 3 V with SW11. Running 3 V GPIO with heavy load may degrade the LTE RF performance. For more information, see GPIO - General purpose input/output in the nRF9160 Objective Product Specification.
VDD powers most of the other circuits the board and will set the GPIO signal amplitude between nRF9160 and other circuits on the board including connectors and PIN headers.
Hi, Martin. Thank you for your reply.
Doesn't connecting 3V to 3.3V affect UART function? I never used 3V UART.
Hi yusuke217,
Since the GPIOs is set to 3V, and I/O pin voltage is VDD_GPIO +/- 0.3V is absolute maximum ratings you should be good.
Also it's worth noticing that the GPIO Threshold is 0.7 x VDD for '1' and 0.3 x VDD for '0'.