Hi There,
The attached image shows the part of the schematic responsible for the enabling of the QM14501. I was wondering if there was a particular reason that the mosfet is controlled by an AND gate rather than using GPIO from the nRF9160 to control it? Any information would be appreciated.
Thanks in advance
Hello,
I was wondering if there was a particular reason that the mosfet is controlled by an AND gate rather than using GPIO from the nRF9160 to control it? Any information would be appreciated
Yes, the reason is due to the antenna tuning. As the Thingy:91 is designed to work worldwide, it is capable of using different bands. The GPS signal is provided through QM12038, see image below form Thingy:91 Hardware Files
When RF_SW1, RF_SW2, and RF_SW3 are all set to one, the GPS band is enabled. The same signals are therefore used to indicate that the LNA can be enabled using the AND gate.
More information can be found in our inforcenter.
Kind regards,
Øyvind
