Texas Instruments LMX2572EVM - Page 7

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SNAU217A–August 2017–Revised November 2017
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LMX2572EVM Evaluation Instructions
Table 2. Phase Adjustment Setting
PARAMETER EXAMPLE VALUE
MASH_SEED 800
PLL_DEN 1000
CHDIV 32
VCO_PHASE_SYNC_EN 0
Phase shift = 360° × (800 / 1000) × (1 / 32) = 9°. We can write 800 to MASH_SEED 40 times to get 360°
phase shift.
Figure 7. Phase Adjustment Setting
Figure 8. Phase Adjustment
3.2.2 Calibration-free Automatic Ramping
LMX2572 supports linear frequency ramp without the need of VCO calibration in the middle of the ramp.
The output waveform is a continuous frequency sweep between the start and the end frequencies.
However, the frequency ramp range is limited. When using ramp, the followings need to be set
accordingly:
• OUT_FORCE = 1
• LD_DLY = 0
• PLL_DEN = 2
32
– 1