Ensure nPM1300 never enters sleep mode

[R.J. Helder]

Hello,

Developing a new pcb with combined nRF9160, nRF5340 and nRF7000. We want to power the system with a nPM1300 PMIC. nRF9160_VDD on VSYS(4.5V), nRF9160_VDD_GPIO on VOUT2(3.3V), nRF5340 on VOUT1(3.3V), nRF7000 on VSYS trough seperate buck regulator (3.3V).

We wil not be using USB but power VBUS directly from a regulated power supply (4.5V). System will be provided with a LiPo battery on VBAT.

We do not want to use shipmode or hypernation mode due to the fact that the system is used 'in the field' and there is no physical access to push a button. How can we prevent the nPM1300 going into shipmode when the external power on VBUS is removed? The device has to stay running on battery power in that situation and we do not want the device go into shipmode. Is it an option to tie SHPHLD-pin directly to VBAT to prevent going into shipmode? 

Please help us out here.

Thank you in advance!

[ketiljo]

The SHPHLD pin have an internal pullup to VBAT so no need to do anything with this if you're going to use it. The default setting of this pin is to exit shipmode only. To enter shipmode, you have to enable this by writing to the register. 

[R.J. Helder]

Ok, perfect! Just wanted to make sure the device doesn't accedentally enters shipmode. Thank you for your answer!

But we have another question:

We want to combine the nRF9160, nRF5340 and nRF7000. We also want to use Macronix MX25L12833FZNI-10G-TR flash IC for external memory (mainly used for FOTA updates).

Can you tell us the prefered hierarchy between the chips and the best option to connect the chips. We want FOTA to be downloaded via the nRF9160 to update the 9160 as well as the nRF5340. 

[ketiljo]

nPM1300 can supply the nRF5340 from the BUCK output and the nRF9160 from the VSYS output. If you are using the nRF7000 for scanning only, you can use the nPM1300 BUCK for this as well, provided it's set to >2.9 V. With 3.0 V output, you can supply them all from the nPM1300.

If you are going to use QSPI for the flash device, see this https://docs.nordicsemi.com/bundle/errata_nRF5340_Rev1/page/ERR/nRF5340/Rev1/latest/anomaly_340_136.html#anomaly_340_136 and https://docs.nordicsemi.com/bundle/errata_nRF5340_Rev1/page/ERR/nRF5340/Rev1/latest/anomaly_340_133.html

[R.J. Helder]

Thank you very much for your clear answer!