In the MAX32600 what is VDDA3 and where does it derive its power from?

VDDA3 is an output of the MAX32600 intended to supply the analog circuitry by shorting or connecting through filter networks to the VDDA3ADC, VDDA3DAC, and VDDA3REF inputs. VDDA3 derives its power from the higher of VDDB (which is derived from USB power) or from the digital supply VDD. This means that when no USB power is present, the minimum VDD voltage allowed is 2.3V if the analog circuitry is desired.