REVISION A 4/20/15
841654 DATA SHEET
5 FEMTOCLOCKS™ CRYSTAL-TO-HCSL
CLOCK GENERATOR
TABLE 5. CRYSTAL CHARACTERISTICS
Parameter Test Conditions Minimum Typical Maximum Units
Mode of Oscillation Fundamental
Frequency 25 MHz
Equivalent Series Resistance (ESR) 50
Ω
Shunt Capacitance 7pF
NOTE: Characterized using an 18pF parallel resonant crystal.
TABLE 6A. LVCMOS AC CHARACTERISTICS, V
DD
= 3.3V±5%, TA = -40°C TO 85°C
Symbol Parameter Test Conditions Minimum Typical Maximum Units
f
MAX
Output Frequency REF_OUT 25 MHz
t
R
/ t
F
Output Rise/Fall Time 20% to 80% 0.60 1.80 ns
odc Output Duty Cycle 49 51 %
TABLE 6B. HCSL AC CHARACTERISTICS, V
DD
= V
DDOA
= V
DDOB
= 3.3V±5%, TA = -40°C TO 85°C
Symbol Parameter Test Conditions Minimum Typical Maximum Units
f
MAX
Output Frequency
VCO/5 100 MHz
VCO/4 125 MHz
tjit(Ø)
RMS Phase Jitter (Random);
NOTE 1
100MHz,
(1.875MHz - 20MHz)
0.44 ps
125MHz,
(1.875MHz - 20MHz)
0.44 ps
tjit(cc)
Cycle-to-Cycle Jitter; NOTE 3 35 ps
tsk(o)
Output Skew;
NOTE 2, 3
QAx/nQAx,
QBx/nQBx
100 ps
t
L
PLL Lock Time 100 ms
V
HIGH
Voltage High 125MHz 650 700 950 mV
V
LOW
Voltage Low -150 150 mV
V
OVS
Max. Voltage, Overshoot 0.3 V
V
UDS
Min. Voltage, Undershoot -0.3 V
V
rb
Ringback Voltage 0.2 V
V
CROSS
Absolute Crossing Voltage 200 550 mV
ΔV
CROSS
Total Variation of V
CROSS
over all edges
160 mV
t
R
/ t
F
Output Rise/Fall Time
QAx/nQAx,
QBx/nQBx
measured between
0.175V to 0.525V
100 700 ps
Δt
R
/Δt
F
Rise/Fall Time Variation 125 ps
odc Output Duty Cycle
QAx/nQAx,
QBx/nQBx
48 52 %
NOTE: All specifi cations are taken at 100MHz and 125MHz.
NOTE 1: Please refer to the Phase Noise Plot.
NOTE 2: Defi ned as skew between outputs at the same supply voltage and with equal load conditions.
Measured at the output differential cross points.
NOTE 3: This parameter is defi ned in accordance with JEDEC Standard 65.
