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Altera_Forum's avatar
Altera_Forum
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14 years ago

DAC/ADC not at full range.

I am using the THDB_ADA daughter card and the DE2-115. I am feeding an NCO output (2Vpp sine wave) from the DAC straight into the ADC through an SMA cable. However, the values registered by the ADC o...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Is the output frequency above the transformer cut-off frequency? Did you measure 2 Vpp with 50 ohm load or open circuit? The AD input has 50 ohm impedance, thus it's halving the magnitude.