
AD9518-4
Data Sheet
Rev. B | Page 6 of 64
CLOCK INPUTS
Table 3.
Parameter
Min
Typ
Max
Unit
Test Conditions/Comments
CLOCK INPUTS (CLK, CLK)
Differential input
Input Frequency
2.4
GHz
High frequency distribution (VCO divider)
1.6
GHz
Distribution only (VCO divider bypassed)
Input Sensitivity, Differential
150
mV p-p
Measured at 2.4 GHz; jitter performance is
improved with slew rates > 1 V/ns
Input Level, Differential
2
V p-p
Larger voltage swings may turn on the
protection diodes and may degrade jitter
performance
Input Common-Mode Voltage, VCM
1.3
1.57
1.8
V
Self-biased; enables ac coupling
Input Common-Mode Range, VCMR
1.3
1.8
V
With 200 mV p-p signal applied; dc-coupled
Input Sensitivity, Single-Ended
150
mV p-p
CLK ac-coupled; CLK ac-bypassed to RF ground
Input Resistance
3.9
4.7
5.7
kΩ
Self-biased
Input Capacitance
2
pF
1 Below about 1 MHz, the input should be dc-coupled. Care should be taken to match VCM.
CLOCK OUTPUTS
Table 4.
Parameter
Min
Typ
Max
Unit
Test Conditions/Comments
LVPECL CLOCK OUTPUTS
Termination = 50 Ω to VS 2 V
OUT0, OUT1, OUT2, OUT3, OUT4, OUT5
Differential (OUT, OUT)
Output Frequency, Maximum
2950
MHz
Using direct to output; see
Figure 16 for peak-
to-peak differential amplitude
Output High Voltage (VOH)
VS_LVPECL
1.12
VS_LVPECL
0.98
VS_LVPECL
0.84
V
Output Low Voltage (VOL)
VS_LVPECL
2.03
VS_LVPECL
1.77
VS_LVPECL
1.49
V
Output Differential Voltage (VOD)
550
790
980
mV
This is VOH VOL for each leg of a differential pair
for default amplitude setting with driver not
toggling; the peak-to-peak amplitude measured
using a differential probe across the differential
pair with the driver toggling is roughly 2× these
values (see
Figure 16 for variation over frequency)
TIMING CHARACTERISTICS
Table 5.
Parameter
Min
Typ
Max
Unit
Test Conditions/Comments
LVPECL
Termination = 50 Ω to VS 2 V; level = 810 mV
Output Rise Time, tRP
70
180
ps
20% to 80%, measured differentially
Output Fall Time, tFP
70
180
ps
80% to 20%, measured differentially
PROPAGATION DELAY, tPECL, CLK-TO-LVPECL
OUTPUT
High Frequency Clock Distribution
Configuration
835
995
1180
ps
Clock Distribution Configuration
773
933
1090
ps
Variation with Temperature
0.8
ps/°C
OUTPUT SKEW, LVPECL OUTPUT
S1LVPECL Outputs That Share the Same Divider
5
15
ps
LVPECL Outputs on Different Dividers
13
40
ps
All LVPECL Outputs Across Multiple Parts
220
ps
1 This is the difference between any two similar delay paths while operating at the same voltage and temperature.