XRK4991A Datasheet, PDF (9/13 Pages) Exar Corporation – 3.3V HIGH-SPEED (85 MHZ) PROGRAMMABLE SKEW CLOCK BUFFER

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REV. P1.0.2
PRELIMINARY
XRK4991A
3.3V HIGH-SPEED (85 MHZ) PROGRAMMABLE SKEW CLOCK BUFFER
TABLE 7: SWITCHING CHARACTERISTICS (3.3V + 10% OPERATING RANGE)
SYMBOL
PARAMETER
XRK4991A-2
XRK4991A-5
XRK4991A-7
UNIT
MIN TYP MAX MIN TYP MAX MIN TYP MAX
F_NOM VCO Frequency Range
t_{RPWH CLKIN Pulse Width HIGH}⁽¹¹⁾
See PLL Programmable Skew Range and Resolution Table
3
3
3
ns
t_{RPWL CLKIN Pulse Width LOW}⁽¹¹⁾
3
3
3
ns
t_u Programmable Skew Time Unit
t_SKEWPR Zero Output Matched-Pair Skew (Qx[1:0])
[1,2,3]
t_{SKEW0 Zero Output Skew (All Outputs)} ^{[1, 4]}
See Control Summary Table
0.05 0.2
0.1 0.25
0.1 0.25 ns
0.1 0.25
0.25 0.5
0.3 0.75 ns
t_SKEW1 Output Skew (Rise-Rise, Fall-Fall, Same
Class Outputs ^{[1, 6]}
0.25 0.5
0.6 0.7
0.6 1 ns
t_SKEW2 Output Skew (Rise-Fall, Divided-Divided)
[1, 6]
t_SKEW3 Output Skew (Rise-Rise, Fall-Fall, Differ-
ent Class Outputs) ^{[1, 6]}
0.3 1.2
0.25 0.5
0.5 1.2
0.5 0.7
1 1.5 ns
0.7 1.2 ns
t_SKEW4 Output Skew
(Rise-Fall, Nominal-Divided, ^{[1, 2]}
0.5 0.9
0.5 1
1.2 1.7 ns
t_{DEV Device-to-Device Skew} ^{[1, 2, 7]}
0.75
1.25
1.65 ns
t_PD CLKIN Input to FB_IN Propagation Delay -0.25 0 0.25 -0.5 0
[1, 9]
t_{ODCV Output Duty Cycle Variation from 50%} ^[1] -1.2 0 1.2 -1.2 0
0.5 -0.7 0
1.2 -1.2 0
0.7 ns
1.2 ns
t_{PWH Output HIGH Time Deviation from 50%} ^[1,
10]
t_PWL Output LOW Time Deviation from 50%
[1,11]
t_{ORISE Output Rise Time} ^[1]
0.15 1
2
1.5
1.2 0.15 1
2.5
3 ns
3
3.5 ns
1.8 0.15 1.5 2.5 ns
t_{OFALL Output Fall Time} ^[1]
0.15 1 1.2 0.15 1 1.8 0.15 1.5 2.5 ns
t_LOCK
t_JR
PLL Lock Time ^[1,8]
Cycle-to-Cycle Output
Jitter ^[1]
RMS
Peak-to-Peak
0.5
0.5
0.5 ns
25
25
25 ps
200
200
200
NOTES:
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.
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