Internal Reference Voltage

[ULW69]

I notice that the question has been asked as far back as 3 years without any answer!

There are several parts of the datasheet that mentions internal reference voltage sources but I cant find any specific information on the mentioned reference voltages in the datasheet. 

How many internal voltage reference are there in the nRF52840?
How are they related / interconnected and to which function blocks?
Parameters like consistency between devices, accuracy, temperature drift, voltage noise, long term stability are vital information for dimensioning analysis.

Can you please help us to obtain this information!

Thank you!

[Kenneth]

Hi,

We do not really supply detailed design description beyond what is stated in the product specifications. In terms of internal references, these are by name internal, and not intended to be used or exposed to the user. Instead we provide description and electrical parameters for various operation of the chip.

The exception I can think of is the internal reference voltage of the ADC (stated as 0.6 V reference), we do not provide any accuracy of this parameter either over the parameters you describe. However, this may not be critical, since any potential drift can be removed by calculation if you sample your external reference with the SAADC.

Assume the following:

Dout_in = your_input* gain/internal_ref
Dout_ref = your_reference * gain/internal_ref

Dout_scaled = Dout_in / Dout_ref = your_input / your_reference

As long as the internal_ref stays the same between two samples, then it should remove any drift in the "internal stuff".

Best regards,
Kenneth