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DAC38RF83: Carrier Frequency Control

Intellectual 1040 points

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Part Number: DAC38RF83

Hello, 

My application needs a Carrier Freq of 1030MHz and we are currently looking into the DAC38RF83/90. 

We are trying to understand where the Carrier is generated. Is it the NCOs that set the Carrier Quadrature signals?

Please let me know how the Carrier is generated (or induced) and difference between CMIX and FMIX in the Complex Mixer block.

How do I set the Carrier Freq to 1030MHz? If with NCO bits, can you please show the math? 

Thanks! 

  • When using the DAC38RF8x you will send a complex digital signal representing your baseband signal.  The RF DAC will up-convert the signal through the digital modulator to your RF band of choice set by the NCO (numerically controlled oscillator).  The equation for determining the NCO word for programming is dependent on sampling rate and is outlined in section 8.3.17.4 of the datasheet.

    Using the NCO (FMIX mode) allows arbitrary placement of the signal in the RF band.  You can also use the CMIX (coarse mixer) which is limited to N*Fs/8 frequencies for the oscillator.  The CMIX offers a bit lower power consumption but sacrificing flexibility.

    --RJH