CYBLE-222014 iDAC voltage source

[Dirk_6716]

Hello,

I want to use the iDAC in the CYBLE-222014 and was wondering if the Vref supplies the iDAC. If so,

1) is it okay to supply Vref/iDAC with 5.5V and VDD/VDDR with 2.8V?

2) Also, is it okay to leave Vref disconnected when I am not using any analog blocks?

[Vasanth · Accepted solution]

Hi,

Unfortunately no is the answer. The VREF in the board is for the external reference option available for the ADC. The IDAC works on VDD voltage, so the IDAC range is limited by it. 

1)No, as it is limited by VDD voltage.

2) You can leave VREF disconnected if external vref is not used or bypass capacitor is not used for the internal reference source.

Best Regards,
Vasanth