Hello All,
Will appreciate anyone that can clarify the following about K82 Voltage Reference for DAC module.
Datasheet page 52 Note 1 says:
"The DAC reference can be selected to be VDDA or VREFH."
But reference manual page 1429 (46.1.3 12-Bit DAC Reference) says:
"For this device VREF_OUT and VDDA are selectable as the DAC reference.
VREF_OUT is connected to the DACREF_1 input and VDDA is connected to the
DACREF_2 input. Use DACx_C0[DACRFS] control bit to select between these two
options."
I need to use a precision 2.5V reference, should I then connect the Reference Output to VDDA? and leave VREFH floating, I cannot see how to select the VREFH for DAC, for ADC there is the SC register.
Thank you in advance,
Hi,
Please ignore the description of the datasheet. Make the reference manual as a correct that VREF_OUT and VDDA are selectable as the DAC reference.
For your case, an external voltage reference can be used as the DAC voltage reference by connecting it to the VREF_OUT pin and selecting VREF_OUT as the DAC reference.
Hello Fang Li,
Thank you for your answer,
I thought the VREF_OUT pin is an output only, do you mean that I should connect my external reference to this pin?
Since my design only needs DAC and DAC IDDA current is 700uA I was connecting the 2.5V reference to VDDA directly.
Would you please clarify which is the preferred approach?