FemtoClock
®
Crystal-to-3.3V, 2.5V LVPECL
Clock Generator
G
ENERAL
D
ESCRIPTION
The 843023I is a Gigabit Ethernet Clock Generator and a mem-
ber of the HiPerClocks
TM
family of high performance devices from
IDT. The 843023I uses a 25MHz crystal to synthesize 250MHz.
The 843023I has excellent phase jitter performance, over the
1.875MHz – 20MHz integration range. The 843023I is packaged
in a small 8-pin TSSOP, making it ideal for use in systems with
limited board space.
843023I
DATASHEET
F
EATURES
•
One differential 3.3V or 2.5V LVPECL output
•
Crystal oscillator interface designed for 25MHz,
18pF parallel resonant crystal
•
Output frequency range: 240MHz - 320MHz
•
VCO range: 480MHz - 640MHz
•
RMS phase jitter @ 250MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.39ps (typical)
Phase noise:
Offset
Noise Power
100Hz ..................-86.3 dBc/Hz
1kHz ................-114.6 dBc/Hz
10kHz ................-125.6 dBc/Hz
100kHz ................-126.0 dBc/Hz
•
Full 3.3V and 2.5V operating supply
•
-40°C to 85°C ambient operating temperature
•
Available in lead-free (RoHS 6) package
B
LOCK
D
IAGRAM
OE
Pullup
XTAL_IN
XTAL_OUT
25MHz
P
IN
A
SSIGNMENT
Phase
Detector
VCO
Q
nQ
V
CC
XTAL_OUT
XTAL_IN
V
EE
1
2
3
4
8
7
6
5
Q
nQ
V
CC
OE
OSC
÷2
(fixed)
843023I
÷20
(fixed)
8-Lead TSSOP
4.40mm x 3.0mm x 0.925mm package body
G Package
Top View
843023I REVISION B JANUARY 9, 2015
1
©2015 Integrated Device Technology, Inc.
843023I DATA SHEET
T
ABLE
1. P
IN
D
ESCRIPTIONS
Number
1, 6
2, 3
4
5
7, 8
Name
V
CC
XTAL_OUT,
XTAL_IN
V
EE
OE
nQ, Q
Type
Power
Input
Power
Input
Output
Pullup
Description
Core supply pin.
Crystal oscillator interface. XTAL_IN is the input, XTAL_OUT is the output.
Negative supply pin.
Active high output enable. When logic HIGH, the outputs are enabled and
active. When logic LOW, the outputs are disabled and the device is in power
down mode. LVCMOS/LVTTL interface levels.
Differential clock outputs. LVPECL interface levels.
Pullup
refers to internal input resistors. See Table 2, Pin Characteristics, for typical values.
T
ABLE
2. P
IN
C
HARACTERISTICS
Symbol
C
IN
R
PULLUP
Parameter
Input Capacitance
Input Pullup Resistor
Test Conditions
Minimum
Typical
4
51
Maximum
Units
pF
kΩ
FEMTOCLOCKS
®
CRYSTAL-TO-
3.3V, 2.5V LVPECL CLOCK GENERATOR
2
REVISION B 1/9/15
843023I DATA SHEET
A
BSOLUTE
M
AXIMUM
R
ATINGS
Supply Voltage, V
CC
Inputs, V
I
Outputs, I
O
Continuous Current
Surge Current
Package Thermal Impedance,
θ
JA
Storage Temperature, T
STG
4.6V
-0.5V to V
CC
+ 0.5V
50mA
100mA
101.7°C/W (0 mps)
-65°C to 150°C
N OT E : S t r e s s e s b eyo n d t h o s e l i s t e d u n d e r A b s o l u t e
Maximum Ratings may cause permanent damage to the
device. These ratings are stress specifications only. Functional
operation of product at these conditions or any conditions beyond
those listed in the
DC Characteristics
or
AC Characteristics
is not
implied. Exposure to absolute maximum rating conditions for ex-
tended periods may affect product reliability.
T
ABLE
3A. P
OWER
S
UPPLY
DC C
HARACTERISTICS
,
V
CC
= 3.3V±5%, T
A
= -40°C
TO
85°C
Symbol
V
CC
V
CCA
I
EE
Parameter
Core Supply Voltage
Analog Supply Voltage
Power Supply Current
Test Conditions
Minimum
3.135
3.135
Typical
3.3
3.3
Maximum
3.465
3.465
75
Units
V
V
mA
T
ABLE
3B. P
OWER
S
UPPLY
DC C
HARACTERISTICS
,
V
CC
= 2.5V±5%, T
A
= -40°C
TO
85°C
Symbol
V
CC
V
CCA
I
EE
Parameter
Core Supply Voltage
Analog Supply Voltage
Power Supply Current
Test Conditions
Minimum
2.375
2.375
Typical
2.5
2.5
Maximum
2.625
2.625
70
Units
V
V
mA
T
ABLE
3C. LVCMOS/LVTTL DC C
HARACTERISTICS
,
V
CC
= 3.3V±5%
OR
2.5V±5%, T
A
= -40°C
TO
85°C
Symbol
V
IH
V
IL
I
IH
I
IL
Parameter
Input High Voltage
Input Low Voltage
Input High Current
Input Low Current
OE
OE
Test Conditions
V
CC
= 3.3V
V
CC
= 2.5V
V
CC
= 3.3V
V
CC
= 2.5V
V
CC
= V
IN
= 3.465V or 2.625V
V
CC
= 3.465V or 2.625V, V
IN
= 0V
-150
Minimum
2
1.7
-0.3
-0.3
Typical
Maximum
V
CC
+ 0.3
V
CC
+ 0.3
0.8
0.7
5
Units
V
V
V
V
µA
µA
T
ABLE
3D. LVPECL DC C
HARACTERISTICS
,
V
CC
= 3.3V±5%
OR
2.5V±5%, T
A
= -40°C
TO
85°C
Symbol
V
OH
V
OL
V
SWING
Parameter
Output High Voltage; NOTE 1
Output Low Voltage; NOTE 1
Peak-to-Peak Output Voltage Swing
Test Conditions
Minimum
V
CC
- 1.4
V
CC
- 2.0
0.6
Typical
Maximum
V
CC
- 0.9
V
CC
- 1.7
1.0
Units
V
V
V
NOTE 1: Outputs terminated with 50Ω to V
CC
- 2V.
REVISION B 1/9/15
3
FEMTOCLOCKS
®
CRYSTAL-TO-
3.3V, 2.5V LVPECL CLOCK GENERATOR
843023I DATA SHEET
T
ABLE
4. C
RYSTAL
C
HARACTERISTICS
Parameter
Mode of Oscillation
Frequency
Equivalent Series Resistance (ESR)
Shunt Capacitance
Drive Level
24
Test Conditions
Minimum
Typical
Fundamental
32
50
7
1
MHz
Ω
pF
mW
Maximum
Units
T
ABLE
5A. AC C
HARACTERISTICS
,
V
CC
= 3.3V±5%, T
A
= -40°C
TO
85°C
Symbol
f
OUT
tjit(Ø)
t
R
/ t
F
odc
Parameter
Output Frequency
RMS Phase Jitter (Random);
NOTE 1
Output Rise/Fall Time
Output Duty Cycle
250MHz,
Integration Range: 1.875MHz - 20MHz
20% to 80%
300
47
Test Conditions
Minimum
240
0.39
600
53
Typical
Maximum
320
Units
MHz
ps
ps
%
NOTE 1: Please refer to the Phase Noise Plot after this section.
T
ABLE
5B. AC C
HARACTERISTICS
,
V
CC
= 2.5V±5%, T
A
= -40°C
TO
85°C
Symbol
f
OUT
tjit(Ø)
t
R
/ t
F
odc
Parameter
Output Frequency
RMS Phase Jitter (Random);
NOTE 1
Output Rise/Fall Time
Output Duty Cycle
250MHz,
Integration Range: 1.875MHz - 20MHz
20% to 80%
300
47
Test Conditions
Minimum
240
0.39
600
53
Typical
Maximum
320
Units
MHz
ps
ps
%
NOTE 1: Please refer to the Phase Noise Plot after this section.
FEMTOCLOCKS
®
CRYSTAL-TO-
3.3V, 2.5V LVPECL CLOCK GENERATOR
4
REVISION B 1/9/15
843023I DATA SHEET
0
-10
-20
-30
-40
-50
T
YPICAL
P
HASE
N
OISE AT
250MH
Z
(3.3V)
➤
Gigabit Ethernet Filter
250MHz
RMS Phase Jitter (Random)
1.875MHz to 20MHz = 0.39ps (typical)
N
OISE
P
OWER
dBc
Hz
-60
-70
-80
-90
-100
-110
-120
-130
-140
-150
-160
-170
-180
-190
100
1k
10k
Raw Phase Noise Data
➤
0
-10
-20
-30
-40
-50
T
YPICAL
P
HASE
N
OISE AT
250MH
Z
(2.5V)
➤
➤
Phase Noise Result by adding
Gigabit Ethernet Filter to raw data
100k
1M
10M
100M
500M
O
FFSET
F
REQUENCY
(H
Z
)
Gigabit Ethernet Filter
250MHz
RMS Phase Jitter (Random)
1.875MHz to 20MHz = 0.39ps (typical)
N
OISE
P
OWER
dBc
Hz
-60
-70
-80
-90
-100
Raw Phase Noise Data
➤
-110
-120
-130
-140
-150
-160
-170
-180
-190
100
1k
10k
O
FFSET
F
REQUENCY
(H
Z
)
REVISION B 1/9/15
➤
Phase Noise Result by adding
Gigabit Ethernet Filter to raw data
100k
1M
10M
100M
500M
5
FEMTOCLOCKS
®
CRYSTAL-TO-
3.3V, 2.5V LVPECL CLOCK GENERATOR
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