I want use the S32K144 to sampling some analog signals. In my project I have 2 different voltage regulators at 5V and I want use the first regulator to supply the microcontroller (VDD pin) and the second regulator as ADC reference supply. From the datasheet (S32K1XX) I see that the pin VDDA (Analog supply voltage) is shorted to VDD. Instead the pin VREFH can be connected to the second voltage regulator or this three voltages must be shorted together to only unique voltage regulator? I not understand the difference between the pins VDDA and VREFH, because in the "Hardware design guidelines for S32K1xx" (AN5426, pag 2) the 3 pins are shorted together.