I use nRF51822 QFAC. DEC1 pin as a reference voltage source?

[VeKa]

I want to create voltage divider for ADC input so I need reference voltage for it. I was wondering if I take it out from DEC1 pin? Any how if I measure voltage from DEC1 pin it seems that it varies few millivolts, depending Sw load I'm using. How stable is this DEC1 voltage output? Is it suitable for using as a reference voltage purposies?

[bjorn-spockeli]

Yes, it should be possible to use the DEC1 pin as a reference voltage, please see this answer where it is used as a reference voltage for the LCOMP.

We do not specify the voltage of the DEC pins in the nRF51822 Product Specification, but we guarantee that its within +/-25mV as this is tested in production.

Best regards

Bjørn