nRF9160 DK v0.8.5

nRF ONLY mode

The nRF ONLY mode disconnects the interface MCU from the nRF9160 using analog switches.

This is done to isolate the chip on the board as much as possible, and can be of use when measuring currents on low-power applications.

Figure 1. nRF ONLY switch (SW1)
PCA10090: nRF ONLY switch (SW1)

The development kit detects if there is a USB cable plugged in (see USB detect) and will disconnect and power down the interface MCU when another supply than the USB is used. If the USB connector is used for power supply only (USB battery back) you can also disable the interface MCU through SW1.

USB detect and SW1 also control the routing of the RESET signal from the RESET button (SW2). Normally, it is routed through the interface MCU, but if that is disabled, the reset button will be routed directly to the nRF9160.

There are also a number of other reset routing options available through the use of solder bridges: