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AD9625 DDC

Question asked by sss on Aug 7, 2015
Latest reply on Aug 7, 2015 by IanB

Hi all,

 

Please advice to me.

 

In the datasheet 33 page ~ "DIGITAL DOWNCONVERTERS (DDC)" @ AD9625,

I can not understand the calculation of the transition band.

 

"HIGH BANDWIDTH DECIMATOR

"The filter yields an effective bandwidth of 120 MHz, with a transition band of 156.5 MHz − 120 MHz = 36.5 MHz.

Therefore, the two-sided complex bandwidth of the filter is 240 MHz. "

 

1.What is the "156.5 MHz" ?

 

 

"LOW BANDWIDTH DECIMATOR

"The filter yields an effective bandwidth of 60 MHz, with a transition band of 81.25 MHz − 60 MHz = 21.25 MHz.

Thus, the two sided, complex bandwidth of the filter is 120 MHz. "

 

2.What is the "81.25MHz" ?

 

Best Regards,

sss

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