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Any PLL chip for synthesizing FMCW reference signal ?

Question asked by J.Park on May 16, 2017
Latest reply on Jun 28, 2017 by icollins

Hi.

 

I'm working on generating FMCW sawtooth signal with DDS-PLL structure.

After gererating 45~57.5 MHz FMCW signal with AD9854, I want to synthesize 720~920 MHz FMCW signal with integer-16 PLL.

(cf 1. Period of the FMCW is under 500 us.

 cf 2. the external reference of the AD9854 is 300 MHz(maximum) signal for high resolution, minimum step time is 1/300MHz ~ 3.33 ns.)

 

However, when I investigate PLL chips, most chips use 'BAND SELECTION' method for tuning VCO. Also, 'band select process' time is around tens of micro-seconds. 

 

Therefore, I think the FMCW signal CANNOT be generated CONTINUOUSLY.

 

Is there any PLL chip that meets above application ?

 

 

Thanks !

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