The AD9146 Filters, Premodulator and modes?

Question

Accepted Answer

Question (1) If I enable the Premodulation and set HB1 and HB2 to mode 1, do I get the 
 signal 
 x(t) = I(t)cos(2*PI*f*t) - Q(t)sin(2*PI*f*t), f = 125 MHz with 4 x 
 interpolation at the I-DAC output, and if not, how do I setup AD9146 in order 
 to obtain this signal.

2) Can you explain how the mixing / modulation is done in the Premodulator, HB1 
 and HB2, so it's easier to predict the the outcome of different settings of the 
 Premodulator, HB1 and HB2. Answer (1) The answer is yes, using Premod modulate the single to Fdata/2 in this 
 case 250MHz/2 = 125Mhz. Selecting HB1 mode 1 and HB2 Mode 1 is the correct 
 filter modes. In this case they only do interpolation the modulation is done by 
 the premod block.
 
 It is Ok to only use the I output but you do need to feed complex data to the 
 input which your email indicates you plan to do.

2) The HB1/2 filters includes modes that modulate to fs/4, fs/2 and 3Fs/4 
 when the premodulation is not turned on. Since you want to mdulate to Fs/8 and 
 are using 4x interpolation the premod block modulates to the fs/8. The mixing 
 is described in table 20. The modulation require I and Q data into the part.
 
 The modes of these filters set the filter center frequency and/or modulation. 
 
 In some filter mode modulation is done but in modes 1 for both HB1 and HB2 
 there is no modulation just the center freq shift to 125MHz.
 
 This diagram from our AD9122 part show how the HB1,2,3 work the AD9146 doesn’t 
 have an HB3.

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AD9146: FAQ