Datasheet

AD9954
Rev. B | Page 35 of 40
SUGGESTED APPLICATION CIRCUITS
03374-012
LPF
AD9954
REFCLK
RF/IF INPUT
MODULATED/
DEMODULATED
SIGNAL
Figure 31. Synchronized LO for Upconversion/Downconversion
03374-013
FILTER
PHASE
COMPARATOR
LOOP
FILTER
AD9954
TUNING
WORD
REF
SIGNAL
VCO
Figure 32. Digitally Programmable Divide-by-N Function in PLL
03374-014
TUNING WORD
CMOS LEVEL CLOCK
AD9954 DDS
AD9954
ON-CHIP
COMPARATOR
IOUT
IOUT
LPF
LPF
Figure 33. Frequency Agile Clock Generator
03374-015
CRYSTAL
FREQUENCY
TUNING
WORD
PHASE
OFFSET
WORD 2
I/I-BAR
BASEBAND
FREQUENCY
TUNING
WORD
PHASE
OFFSET
WORD 1
Q/Q-BAR
BASEBAND
SYNC_IN
AD9954 DDS
REFCLK
REFCLK
REFCLK
LPF
SYNC_OUTCRYSTAL OUT
AD9954 DDS
IOUT
IOUT
LPF
IOUT
IOUT
RF OUT
Figure 34. Two AD9954s Synchronized to Provide I and
Q Carriers with Independent Phase Offsets for Nulling