Issue with Powering nRF9161 DK

[sgordon291]

Dear Nordic TS,

I'm trying to power an nRF9161 DK with a simple external battery.  According to the documentation, I thought that this battery voltage should be applied between VIN 5V and GND and that this voltage must fall between 4.0 V and  5.5 V.  My battery back's voltage is 4.75V.  Pls confirm that this is correct, or let me know what the correct info is.

I have confirmed with a VOM that the unit does see 4.75 V between VIN 5V and GND.  In addition, I have verified that the battery can supply the needed current by tesing the battery's voltage across a 500 ohm resistor.   When I make the connection and turn the unit's slide switch to ON, the unit does not appear to boot.  All LEDs remain dark.  

I'd appreciate know (1) have I made the needed and proper connections to power the nRF9161 and (2) are there any steps you suggest to troubleshoot this.

Thank you.

Best,

Steven Gordon

[WesC]

Steve;
The DK is primarily powered by 5 V from the USB connector J6. Alternatively, the DK can be powered by the VIN 5V pin located on the P20 header. Both sources support voltages in the range of 4.0 V to 5.5 V with a nominal voltage of 5 V. The DK must be powered by only one source at a time.

[sgordon291]

Wes,

I saw that in the documentation.  But I cannot get the power to work through the VIN 5V pin on the P20 header.  For a test, I used a USB charging block that has an available current of 850 mA and verified that the charging block voltage is 5V on an open circuit. Then  I connected the power wires of the charging block to VIN 5V (on the P20 header) and GND.  When I do this and turn the unit on, the voltage from VIN 5V to GND drops to about 3.5 V, and the unit shuts off.

I don't understand the reason for this voltage drop, and I think it's causing the unit to fail on startup.

Do you have any insight to what is happening?  If a conversation is a better idea, pls let me know.

Thank you.

Best,

Steven Gordon

[WesC]

try and connect the GND to either P22 or P1.  Dont use the GND on P22 and let me know if that works

[WesC]

Sorry i meant don't use the GND on P20