How to connect VREG_VOUT & DVDD on RP2040?

In almost all cases, to get the RP2040 working,

• Connect VREG_VOUT to DVDD directly, do not connect them to any other voltage.
• Connect a 1uF capacitor to VREG_VOUT (and place it close to the VREG_VOUT pin)
• Connect a 100nF capacitor to DVDD (and place it close to the DVDD pin)

Never connect DVDD to 3.3V or 1.8V, this will kill the chip!

While there is the possibility of using an external (switching) 1.1V regulator, this has little benefit for most applications and is much more involved. I recommend generally not doing that.