Datasheet

Data Sheet AD9547
Rev. E | Page 7 of 104
REFERENCE INPUTS (REFA/REFAA, REFB/REFBB)
Table 8.
Parameter
Min
Typ
Max
Unit
Test Conditions/Comments
DIFFERENTIAL OPERATION
Frequency Range
Sinusoidal Input
10
750
MHz
LVPECL Input
0.001
750
MHz
LVDS Input
0.001
750
MHz
Minimum Input Slew Rate 40 V/µs Minimum limit imposed for jitter performance
Common-Mode Input Voltage
2
V
Internally generated
Differential Input Voltage
Sensitivity
±65
mV
This is the minimum voltage required across the pins to
ensure switching between logic states; the instantaneous
voltage on either pin must not exceed the supply rails
Input Resistance
25
kΩ
Input Capacitance
3
pF
Minimum Pulse Width High 620 ps
Minimum Pulse Width Low 620 ps
SINGLE-ENDED OPERATION
Frequency Range (CMOS)
0.001
250
MHz
Minimum Input Slew Rate
40
V/µs
Minimum limit imposed for jitter performance
Input Voltage High (V
IH
)
1.2 V to 1.5 V Threshold Setting 0.9 V
1.8 V to 2.5 V Threshold Setting 1.2 V
3.0 V to 3.3 V Threshold Setting 1.9 V
Input Voltage Low (V
IL
)
1.2 V to 1.5 V Threshold Setting
0.27
V
1.8 V to 2.5 V Threshold Setting
0.5
V
3.0 V to 3.3 V Threshold Setting
1.0
V
Input Resistance
45
kΩ
Input Capacitance 3 pF
Minimum Pulse Width High 1.5 ns
Minimum Pulse Width Low 1.5 ns
REFERENCE MONITORS
Table 9.
Parameter
Min
Typ
Max
Unit
Test Conditions/Comments
REFERENCE MONITOR
Loss of Reference Detection Time
1.2
NPDP
NPDP = nominal phase detector period (NPDP = f
REF
/R)
1
Frequency Out-of-Range Limits 9.54 × 10
−7
0.1 Δf/f
REF
Programmable (lower bound subject to quality of SYSCLK)
TIMERS
Validation Timer
0.001
65.535
sec
Programmable in 1 ms increments
Redetect Timer
0.001
65.535
sec
Programmable in 1 ms increments
1
f
REF
is the frequency of the active reference; R is the frequency division factor determined by the R divider.