nRF9160 - Power Management for supply from LiFePO4 Cell

[Risto]

Hi there,

I want to use a LiFePO4 Cell to supply the nRF9160:

1. Is the MAX17224 suitable to power the nRF9160?
2. Is this Power "Sequence" OK?
   Productspecification nRF9160 1.1 says:
   - VDD_GPIO should be applied after VDD has been supplied.
   - VDD_GPIO should be removed before removing VDD.
   Is this a must have? or is it allowed to supply VDD_GPIO, VDD somehow "simultaneously" (both DC/DC's enabled) as drawn in the block diagram?
    

Risto

[Andreas]

HI,

 

1) Looks to be able to supply 1A, which should be sufficient. You should ensure though that your supply is able to supply a stable voltage across the current consumption range of the nRF9160, so you should include your battery in this investigation also.

2) Yes this is fine. The note is mostly a precaution as far as I understand, though we do not recommend that you keep VDD_GPIO powered for prolonged periods without power on VDD.

 

Best regards,

Andreas