Use nRF52840 as nRF52833

[DX_HK]

I am developing a product that uses Gazell and USB.
During development, I am using the nRF52840 due to availability. For mass production, I will use the nRF52833 to reduce costs.

Looking at the nRF52 Series comparison table, the differences between the nRF52833 and nRF52840 appear to be the RAM, Flash, built-in DCDC converter, and CryptoCell.
These differences do not affect development.

The development board is already designed for the nRF52833, and the filter inductor has been removed.
However, when I tried to operate the nRF52840's Reg0 in LDO mode, it did not work.Therefore, I built it as an nRF52833 and wrote the binary, and it worked.
In general, writing a smaller capacity image to a larger capacity MCU will work, but this is not a legitimate procedure.

Questions:
1. What problems are anticipated that may arise from using an image built as nRF52833?
2. Is it possible to operate Reg0 of nRF52840 in LDO mode by appropriate means using the current nRF Connect SDK?

[Jared]

Hi,

However, when I tried to operate the nRF52840's Reg0 in LDO mode, it did not work.

Can you expand on what you tried to do here? Was the project built for the nRF52840 or the nRF52833, and what exactly did you try to do that didn't work? How did it fail, was any error code returned?

1. What problems are anticipated that may arise from using an image built as nRF52833?

The nRF52833 and nRF52840 is very similar but have different level of support for some peripherals. It's not safe to build a project for nRF52833 and then run it on the nRF52840, there might be some dependencies that will make the project assert. 

2. Is it possible to operate Reg0 of nRF52840 in LDO mode by appropriate means using the current nRF Connect SDK?

Using nRF52840 with LDO is fully supported. You just have to make sure that the DC/DC is not enabled in the project configs. Have you tried this?

regards

Jared