Can I run the GPIO’s / digital lines / SPI on 3.3V by connecting IOVDD and DVDD to 3.3V and then run the ADC’s and DAC’s on 5V by connecting AVDD1/2 and AVCC1/2 to 5V – just want to check this ?
I think I can tie DVdd / AVdd / AVcc to 5V and I/OVdd to 3.3V, then any digital lines and GPIO’s could have pull up resistors to 3.3V to interface with 3.3V logic and my SPI bus and CS all will be 3.3V – can this be done ?
Hello Paul,
I have posted the power-supply requirements below for reference. To summarize, you can definitely do the second power scheme suggested, but just not the first.
The first is invalid because the digital power supply, DVDD, must be the same value as the positive analog supply, AVDD. (page 8 of DS)
So, in following your second scheme you can power DVDD/AVDD/AVCC to 5V, and use 3.3V on IOVDD. The digital lines and GPIO can then have pullups to 3.3V.
An example schematic is provided in the following link, which provides a sample schematic and layout for the device:
http://www.ti.com/lit/pdf/sbau177
Best Regards,
Matt
