Datasheet

AD9549
Rev. D | Page 73 of 76
APPLICATIONS INFORMATION
SAMPLE APPLICATIONS CIRCUIT
CLK
CLKB
SYNCB
LOW-PASS
FILTER
AD9514
/1...../32
/1...../32
/1...../32
Δ t
OUT0/
OUT0B
OUT1/
OUT1B
OUT2/
OUT2B
SYSCLK
INPUT A
INPUT B
06744-059
AD9549
DDS/
DAC
REF A
REF B
DIFF HSTL OUTPUT
FDBK_IN
FDBK_INB
CMOS OUTPUT
LDDS/CMOS
LVPECL
LVPECL
Figure 59. AD9549 and AD9514 Precision Clock Distribution Circuit
Applications Circuit Features
Features of this applications circuit include the following:
• Input frequencies down to 8 kHz; output frequencies up to
400 MHz
• Programmable loop bandwidth down to <1 Hz
• Automatic redundant clock switchover with user-selectable
rate-of-phase adjustment
• Automatic Stratum 3/3E clock holdover, depending on the
configuration
• Phase noise (f
C
= 122.3 MHz and 100 Hz loop bandwidth);
100 Hz offset: −107 dBc/Hz; 1 kHz offset: −142 dBc/Hz;
100 kHz offset: −157 dBc/Hz; two zero-delay outputs with
programmable postdivider and synchronization
• Two additional outputs (nonzero delay) on the AD9549
• Programmable skew adjustment on one AD9514 output