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Electronics => Beginners => Topic started by: auccapuclla on February 06, 2021, 04:49:20 am

Title: Power Up AD5683R
Post by: auccapuclla on February 06, 2021, 04:49:20 am

Hello all. I am trying to power up the AD5683R with an Arduino Uno. Checking the datasheet I came upon the attached image.

Could you please tell me how to power up this chip with Arduino Uno?

Btw, I will communicate both through SPI.

https://www.analog.com/media/en/technical-documentation/data-sheets/AD5683R_5682R_5681R_5683.pdf?fbclid=IwAR1fKapaSx58ITTJm9vib4YxC621ALToNl1SYDtX4c80U07FQkNBnELPjeY (https://www.analog.com/media/en/technical-documentation/data-sheets/AD5683R_5682R_5681R_5683.pdf?fbclid=IwAR1fKapaSx58ITTJm9vib4YxC621ALToNl1SYDtX4c80U07FQkNBnELPjeY)

Hope someone could help me.

Title: Re: Power Up AD5683R
Post by: mvs on February 06, 2021, 11:13:53 am

You will need to connect SDI to MOSI (D11), SCLK to SCK (D13), /SYNC to any unused digital pin, GND to GND, Vlogic and Vdd to 5V.
/LDAC and /RESET are optional, you can connect them to any unused digital pins or to 5V if you do not want to use them. Add also decoupling caps on Vlogic, Vdd and REF.

Configure arduino peripherals:
set SPI mode to 1 or 2, MSB first
configure pins connected to /SYNC, /LDAC and /RESET as outputs and set them high.

To write 3 bytes do following:
set /SYNC low
write 3 bytes to SPI
set /SYNC high

If you use software /LDAC, you can issue "update DAC register" command to load the data from input register to DAC register.
As alternative you may load data directly with "write DAC and input register" command.

If you use hardware /LDAC, you can set it low and then high to load the data from input register to DAC register.

Title: Re: Power Up AD5683R
Post by: auccapuclla on February 06, 2021, 02:33:40 pm

Thanks for your answer  :).

I was thinking in connect Vlogic and Vdd to the 5V output pin of the Arduino and the Vref to the 3.3V pin, and connect a capacitor in parallel in each connection. Do u think connecting in this way will cause me trouble?

Btw, is it necessary to power Vref or can I leave this pin open?

Thanks in advance.

Title: Re: Power Up AD5683R
Post by: mvs on February 06, 2021, 02:56:58 pm

AD5683R has build in 2.5V reference with better accuracy and lower drift, then 3.3V LDO of Arduino Uno.
You can left Vref pin open or just connect 10nF cap to it to decrease noise.