xr
REV. P1.0.2
XRK4991A
3.3V HIGH-SPEED (85 MHZ) PROGRAMMABLE SKEW CLOCK BUFFER
T
ABLE
7: S
WITCHING
C
HARACTERISTICS
(3.3
V
+
10% O
PERATING
R
ANGE
)
PRELIMINARY
S
YMBOL
F
NOM
t
RPWH
t
RPWL
t
u
P
ARAMETER
VCO Frequency Range
CLKIN Pulse Width HIGH
(11)
CLKIN Pulse Width LOW
(11)
Programmable Skew Time Unit
XRK4991A-2
M
IN
T
YP
M
AX
XRK4991A-5
M
IN
T
YP
M
AX
XRK4991A-7
M
IN
T
YP
M
AX
U
NIT
See PLL Programmable Skew Range and Resolution Table
3
3
3
3
3
3
ns
ns
See Control Summary Table
0.05
0.1
0.25
0.3
0.25
0.5
0.2
0.25
0.5
1.2
0.5
0.9
0.1
0.25
0.6
0.5
0.5
0.5
0.25
0.5
0.7
1.2
0.7
1
0.1
0.3
0.6
1
0.7
1.2
0.25
0.75
1
1.5
1.2
1.7
ns
ns
ns
ns
ns
ns
t
SKEWPR
Zero Output Matched-Pair Skew (Qx[1:0])
[1,2,3]
t
SKEW0
t
SKEW1
t
SKEW2
t
SKEW3
t
SKEW4
t
DEV
t
PD
t
ODCV
t
PWH
t
PWL
t
ORISE
t
OFALL
t
LOCK
t
JR
Zero Output Skew (All Outputs)
[1, 4]
Output Skew (Rise-Rise, Fall-Fall, Same
Class Outputs
[1, 6]
Output Skew (Rise-Fall, Divided-Divided)
[1, 6]
Output Skew (Rise-Rise, Fall-Fall, Differ-
ent Class Outputs)
[1, 6]
Output Skew
(Rise-Fall, Nominal-Divided,
[1, 2]
Device-to-Device Skew
[1, 2, 7]
CLKIN Input to FB_IN Propagation Delay
[1, 9]
0.75
-0.25
-1.2
0
0
0.25
1.2
2
1.5
0.15
0.15
1
1
1.2
1.2
0.5
0.15
0.15
1
1
-0.5
-1.2
0
0
1.25
0.5
1.2
2.5
3
1.8
1.8
0.5
25
200
0.15
0.15
1.5
1.5
-0.7
-1.2
0
0
1.65
0.7
1.2
3
3.5
2.5
2.5
0.5
25
200
ns
ns
ns
ns
ns
ns
ns
ns
ps
Output Duty Cycle Variation from 50%
[1]
Output HIGH Time Deviation from 50%
[1,
10]
Output LOW Time Deviation from 50%
[1,11]
Output Rise Time
[1]
Output Fall Time
[1]
PLL Lock Time
[1,8]
Cycle-to-Cycle Output
Jitter
[1]
RMS
Peak-to-Peak
25
200
N
OTES
:
1. All timing and jitter tolerances apply for F
NOM
> 25MHz.
2. Skew is the time between the earliest and the latest output transition among all outputs for which the same tU delay has been
selected when all are loaded with the specified load.
3. t
SKEWPR
is the skew between a pair of outputs (Qx[1:0]) when all eight outputs are selected for 0t
U
.
4. t
SKEW0
is the skew between outputs when they are selected for 0t
U
.
9
EXAR [ EXAR CORPORATION ]
