AFE7950: DDC in AFE7950

AKASH GUPTA

Prodigy 90 points

Part Number: AFE7950

Why the DDC outs I & Q components in Rx chain of AFE7950? What is the significance of I & Q in DDC?

over 2 years ago

0 David Chaparro over 2 years ago

TI__Genius 17831 points

Hi Akash,

The reason that the outputs are complex, I & Q, is because the digital outputs of the ADCs go to a complex mixer where the data is mixed with the NCO frequency, see section 8.3.2 of the datasheet for the RX Chain Block Diagram. The benefit of using the complex mixer is that the the output I and Q data occupies half the bandwidth of the input signal and the image and carrier components are naturally suppressed.

See this post for additional information on real and complex mixers: https://e2e.ti.com/blogs_/b/analogwire/posts/rf-sampling-digital-mixers-make-mixing-fun

Regards,

David Chaparro

RF & microwave

RF & microwave forum

AFE7950: DDC in AFE7950