Texas Instruments High Performance Frequency Synthesizer System with Integrated VCO LMX25312820EVAL/NOPB LMX25312820EVAL/NOPB 데이터 시트

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LMX25312820EVAL/NOPB
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Free-Running VCO Phase Noise (Internal Divide by 2 Disabled) 
Fout = ~2710 MHz 
 
The plots to the left show the true phase 
noise capability of the VCO.  In order to 
take these plots, the E5052 phase nose 
analyzer was used.   The method was to 
lock the PLL to the proper frequency, then 
disable the EN_PLL, EN_PLLLDO1, 
EN_PLLLDO2, EN_DIGLDO, and 
EN_OSC bits.  The equipment needs to be 
able to track the VCO phase noise to 
measure in this way, and one can not let 
the VCO drift too far off in frequency.  If this 
kind of equipment is not available, the 
VCO phase noise can also be measured 
by making a very narrow loop bandwidth 
filter. 
 
 
Fout = ~2820 MHz 
 
Fout = ~2920 MHz