Datasheet

AD9548 Data Sheet
Rev. E | Page 8 of 112
REFERENCE SWITCHOVER SPECIFICATIONS
Table 10.
Parameter Min Typ Max Unit Test Conditions/Comments
REFERENCE SWITCHOVER SPECIFICATIONS
Maximum Output Phase Perturbation (Phase
Build-Out Switchover)
40 200 ps Assumes a jitter-free reference; satisfies
Telcordia GR-1244-CORE requirements
Maximum Time/Time Slope (Hitless
Switchover)
315 65,535 ns/sec Minimum/maximum values are
programmable upper bounds; a minimum
value ensures <10% error; satisfies
Telcordia GR-1244-CORE requirements
Time Required to Switch to a New Reference
Hitless Switchover 5 sec Calculated using the nominal phase
detector period (NPDP = R/f
REF
)
1
Phase Build-Out Switchover 3 sec Calculated using the nominal phase
detector period (NPDP = R/f
REF
)
1
1
f
REF
is the frequency of the active reference; R is the frequency division factor determined by the R-divider.
DISTRIBUTION CLOCK OUTPUTS (OUT0 TO OUT3)
Table 11.
Parameter Min Typ Max Unit Test Conditions/Comments
LVPECL MODE Using internal current setting resistor
Maximum Output Frequency 725 MHz
Rise/Fall Time (20% to 80%) 180 315 ps 100 Ω termination across output pins
Duty Cycle 45 55 %
Differential Output Voltage Swing 630 770 910 mV Magnitude of voltage across pins; output
driver static
Common-Mode Output Voltage AVDD3
− 1.5
AVDD3 − 1.3 AVDD3 −
1.05
V Output driver static
LVDS MODE Using internal current setting resistor
(nominal 3.12 kΩ)
Maximum Output Frequency
725
MHz
Rise/Fall Time
1
(20% to 80%) 200 350 ps 100 Ω termination across the output pair
Duty Cycle 40 60 %
Differential Output Voltage Swing
Balanced, V
OD
247 454 mV Voltage swing between output pins;
output driver static
Unbalanced, ΔV
OD
50 mV Absolute difference between voltage
swing of normal pin and inverted pin;
output driver static
Offset Voltage
Common-Mode, V
OS
1.125 1.375 V Output driver static
Common-Mode Difference, ΔV
OS
50 mV Voltage difference between pins; output
driver static
Short-Circuit Output Current 13 24 mA Output driver static
CMOS MODE
Weak drive option not supported for
operating the CMOS drivers using a 1.8 V
supply
Maximum Output Frequency
3.3 V Supply 10 pF load
Strong Drive Strength Setting 250 MHz
Weak Drive Strength Setting 25 MHz
1.8 V Supply 150 MHz