FemtoClock
®
Crystal-to-3.3V, 2.5V
LVPECL Clock Generator
843071
DATA SHEET
General Description
The 843071 is a Serial ATA (SATA)/Serial Attached SCSI (SAS)
Clock Generator. The 843071 uses an 18pF parallel resonant crystal
over the range of 20.833MHz - 28.3MHz. For SATA/SAS
applications, a 25MHz crystal is used and either 75MHz or 150MHz
may be selected with the FREQ_SEL pin. For 10Gb Fibre Channel
applications, a 26.5625MHz crystal is used for 159.375MHz output.
The 843071 has excellent <1ps phase jitter performance, over the
12kHz - 20MHz integration range. The 843071 is packaged in a
small 8-pin TSSOP, making it ideal for use in systems with limited
board space.
Features
•
•
•
•
•
•
•
•
•
One differential 3.3V or 2.5V LVPECL output
Crystal oscillator interface,18pF parallel resonant crystal
(20.833MHz – 28.3MHz)
Output frequency range: 62.5MHz – 170MHz
VCO range: 500MHz – 680MHz
RMS phase jitter at 150MHz, using a 25MHz crystal
(12kHz – 20MHz): 0.64ps (typical) @ 3.3V output
RMS phase jitter at 159.375MHz, using a 26.5625MHz crystal
(1.875MHz – 20MHz): 0.40ps (typical) @ 3.3V output
Full 3.3V or 2.5V operating supply
-40°C to 85°C ambient operating temperature
Available in lead-free (RoHS 6) package
Common Configuration Table - Serial ATA/Serial Attached SCSI
Inputs
Crystal Frequency (MHz)
25
25
26.5625
FREQ_SEL
0
1
0
M
24
24
24
N
4
8
4
Multiplication Value M/N
6
3
6
Output Frequency (MHz)
150
75
159.375
Block Diagram
FREQ_SEL
Pullup
Pin Assignment
V
CCA
XTAL_OUT
XTAL_IN
V
EE
1
2
3
4
8
7
6
5
V
CC
Q
nQ
FREQ_SEL
XTAL_IN
OSC
XTAL_OUT
Phase
Detector
VCO
500MHz - 680MHz
FREQ_SEL N
0
÷4
1
÷8
Q0
nQ0
843071
8 Lead TSSOP
4.40mm x 3.0mm package body
M = ÷24
(fixed)
843071 REVISION C 10/19/15
1
©2015 Integrated Device Technology, Inc.
843071 DATA SHEET
Pin Description and Pin Characteristic Tables
Table 1. Pin Descriptions
Number
1
2,
3
4
5
6, 7
8
Name
V
CCA
XTAL_OUT
XTAL_IN
V
EE
FREQ_SEL
nQ, Q
V
CC
Power
Input
Power
Input
Output
Power
Pullup
Type
Description
Analog supply pin.
Crystal oscillator interface. XTAL_IN is the input, XTAL_OUT is the output.
Negative supply pin.
Frequency select pin. LVCMOS/LVTTL interface levels.
Differential output pair. LVPECL interface levels.
Core supply pin.
NOTE:
Pullup
refers to internal input resistors. See Table 2,
Pin Characteristics,
for typical values.
Table 2. Pin Characteristics
Symbol
C
IN
R
PULLUP
Parameter
Input Capacitance
Input Pullup Resistor
Test Conditions
Minimum
Typical
4
51
Maximum
Units
pF
k
FEMTOCLOCK
®
CRYSTAL-TO-3.3V, 2.5V LVPECL CLOCK GENERATOR
2
REVISION C 10/19/15
843071 DATA SHEET
Absolute Maximum Ratings
NOTE: Stresses beyond those listed under
Absolute 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
extended periods may affect product reliability.
Item
Supply Voltage, V
CC
Inputs, V
I
Outputs, I
O
Continuous Current
Surge Current
Package Thermal Impedance,
JA
Storage Temperature, T
STG
Rating
4.6V
-0.5V to V
CC
+ 0.5V
50mA
100mA
101.7C/W (0 mps)
-65C to 150C
DC Electrical Characteristics
Table 3A. Power Supply DC Characteristics,
V
CC
= V
CCA
= 3.3V ± 10%, V
EE
= 0V, T
A
= -40°C to 85°C
Symbol
V
CC
V
CCA
I
CC
I
CCA
I
EE
Parameter
Core Supply Voltage
Analog Supply Voltage
Power Supply Current
Analog Supply Current
Power Supply Current
Test Conditions
Minimum
3.0
3.0
Typical
3.3
3.3
Maximum
3.63
3.63
96
12
72
Units
V
V
mA
mA
mA
Table 3B. Power Supply DC Characteristics,
V
CC
= V
CCA
= 2.5V ± 5%, V
EE
= 0V, T
A
= -40°C to 85°C
Symbol
V
CC
V
CCA
I
CC
I
CCA
I
EE
Parameter
Core Supply Voltage
Analog Supply Voltage
Power Supply Current
Analog Supply Current
Power Supply Current
Test Conditions
Minimum
2.375
2.375
Typical
2.5
2.5
Maximum
2.625
2.625
72
12
72
Units
V
V
mA
mA
mA
Table 3C. LVCMOS/LVTTL DC Characteristics,
V
CC
= V
CCA
= 3.3V ± 10%, 2.5V ± 5%, V
EE
= 0V, T
A
= -40°C to 85°C
Symbol
V
IH
Parameter
Input High Voltage
2.5V
3.3V
V
IL
I
IH
I
IL
Input Low Voltage
2.5V
Input High Current
Input Low Current
V
CC
= V
IN
= 3.63V or 2.625V
V
CC
= 3.63V or 2.625V, V
IN
= 0V
-150
-0.3
0.7
5
V
µA
µA
1.7
-0.3
Test Conditions
3.3V
Minimum
2
Typical
Maximum
V
CC
+ 0.3
V
CC
+ 0.3
0.8
Units
V
V
V
REVISION C 10/19/15
3
FEMTOCLOCK
®
CRYSTAL-TO-3.3V, 2.5V LVPECL
CLOCK GENERATOR
843071 DATA SHEET
Table 3D. LVPECL DC Characteristics,
V
CC
= V
CCA
= 3.3V ± 10%, 2.5V ± 5%, V
EE
= 0V, 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 termination with 50 to V
CC
– 2V.
Table 4. Crystal Characteristics
Parameter
Mode of Oscillation
Frequency
Equivalent Series Resistance (ESR)
Shunt Capacitance
Drive Level
20.833
Test Conditions
Minimum
Typical
Fundamental
28.3
50
7
1
MHz
Maximum
Units
pF
mW
AC Electrical Characteristics
Table 5A. AC Characteristics,
V
CC
= 3.3V ± 10%, V
EE
= 0V, T
A
= -40°C to 85°C
Symbol
f
OUT
Parameter
Output Frequency
150MHz, Integration Range: 12kHz – 20MHz
tjit(Ø)
RMS Phase Jitter,
Random; NOTE 1
Output Rise/Fall Time
Output Duty Cycle
75MHz, Integration Range: 12kHz – 20MHz
159.375MHz,
Integration Range: 1.875MHz – 20MHz
20% to 80%
250
48
Test Conditions
Minimum
62.5
0.64
0.64
0.40
500
52
Typical
Maximum
170
Units
MHz
ps
ps
ps
ps
%
t
R
/ t
F
odc
NOTE: Electrical parameters are guaranteed over the specified ambient operating temperature range, which is established when the device is
mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after thermal equilibrium
has been reached under these conditions.
NOTE 1: Please refer to Phase Noise Plots.
Table 5B. AC Characteristics,
V
CC
= 2.5V ± 5%, V
EE
= 0V, T
A
= -40°C to 85°C
Symbol
f
OUT
Parameter
Output Frequency
150MHz, Integration Range: 12kHz – 20MHz
tjit(Ø)
RMS Phase Jitter,
Random; NOTE 1
Output Rise/Fall Time
Output Duty Cycle
75MHz, Integration Range: 12kHz – 20MHz
159.375MHz,
Integration Range: 1.875MHz – 20MHz
20% to 80%
250
48
Test Conditions
Minimum
62.5
0.94
0.80
0.42
500
52
Typical
Maximum
170
Units
MHz
ps
ps
ps
ps
%
t
R
/ t
F
odc
NOTE: Electrical parameters are guaranteed over the specified ambient operating temperature range, which is established when the device is
mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after thermal equilibrium
has been reached under these conditions.
NOTE 1: Please refer to Phase Noise Plots.
FEMTOCLOCK
®
CRYSTAL-TO-3.3V, 2.5V LVPECL CLOCK GENERATOR
4
REVISION C 10/19/15
843071 DATA SHEET
Typical Phase Noise at 75MHz (3.3V)
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
-150
-160
-170
-180
-190
-200
➝
➝
Filter
75MHz
RMS Phase Jitter (Random)
12kHz to 20MHz = 0.64ps (typical)
Noise Power dBc
Hz
Raw Phase Noise Data
Phase Noise Result by adding
a filter to raw data
Offset Frequency (Hz)
➝
REVISION C 10/19/15
5
FEMTOCLOCK
®
CRYSTAL-TO-3.3V, 2.5V LVPECL
CLOCK GENERATOR
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