AD9102 - DAC CONSTANT issue

Hi RubenEDERY , 

Please see the Power Supply Notes section in Page 28 of Rev B datasheet. Also, since you are generating DC the output datapath must be free from any components that might filter it out (such as baluns, etc.). C507 might be filtering out the DC value. Better to use an Op-amp configuration like in the AD9102 Evaluation Board Schematic (Rev B) for DC signal output.

Best regards,
Marco

Hi RubenEDERY , 

Please see the Power Supply Notes section in Page 28 of Rev B datasheet. Also, since you are generating DC the output datapath must be free from any components that might filter it out (such as baluns, etc.). C507 might be filtering out the DC value. Better to use an Op-amp configuration like in the AD9102 Evaluation Board Schematic (Rev B) for DC signal output.

Best regards,
Marco

Hello Marco,

I strapped together DVDD=DLDO1=DLDO2=1.8V and CLKVDD=CLDO=1.8V  and configure Register Adress 0x01 at value 0x01C7 as requested.

The DAC output Start at midrange (550mV) with the resistor of 275 ohms. I removed C507 to try. There is no effect on the DAC ouput by changing the DAC_CST register. 

Any devices will be welcome. 

Thanks 

Hi RubenEDERY ,

Are you using the AD9102 Evaluation board? Can you confirm for your setup that you are able to generate a simple sine wave? There doesn't seem to be a problem with the DAC connections, so the issue might be in the DAC output data path, or in your code (if you have a custom build).

Best regards,
Marco

Hello,

I am not using the evaluation board. It's a custom board. I do not need to generate a simple sine wave but i can try. Just a DC constant value to drive an AD8338 variable gain amplifier (VGA). This VGA needs a range of 0 to 1.1V to make the amplification correctly. 

Ruben