FemtoClock®
Crystal/LVCMOS-to-LVPECL/ LVCMOS
Frequency Synthesizer
843001I-23
DATA SHEET
General Description
The 843001I-23 is a highly versatile, low phase noise
LVPECL/LVCMOS Synthesizer which can generate low jitter
reference clocks for a variety of communication applications. The
dual crystal interface allows the synthesizer to support up to three
communication standards in a given application (i.e. SONET with a
19.44MHz crystal, 1Gb/10Gb Ethernet and Fibre Channel using a
25MHz crystal). The RMS phase jitter performance is typically less
than 1ps, thus making the device acceptable for use in demanding
applications such as OC48 SONET, GbE/10Gb Ethernet and SAN
applications. The 843001I-23 is packaged in a small 24-pin TSSOP,
E-Pad package.
Features
•
•
•
•
•
•
•
•
One 3.3Vdifferential LVPECL output pair and
one LVCMOS/LVTTL single-ended reference clock output
Selectable crystal oscillator interface
or LVCMOS/LVTTL single-ended input
Crystal and CLK range: 19.44MHz – 27MHz
Able to generate GbE/10GbE/12GbE, Fibre Channel
(1Gb/4Gb/10Gb), PCI-E and SATA from a 25MHz crystal
VCO range: 1.12GHz – 1.275GHz
Supports the following applications:
SONET, Ethernet, Fibre Channel, Serial ATA, and HDTV
RMS phase jitter @ 622.08MHz (12kHz - 20MHz):
0.9ps (typical), 3.3V
Supply modes
V
CC
/V
CCO
3.3V/3.3V
3.3V/2.5V
2.5V/2.5V
-40°C to 85°C ambient operating temperature
Available in lead-free (RoHS 6) package
•
•
Block Diagram
3
N2:N0
SEL0
Pulldown
SEL1
Pulldown
N
XTAL_IN0
000
001
010
011
100
101
110
111
÷2
÷4
÷5
÷6
÷8
(default)
÷10
÷12
÷16
Pin Assignment
V
CCO_LVCMOS
N0
N1
N2
V
CCO_LVPECL
Q
nQ
V
EE
V
CCA
V
CC
XTAL_OUT1
XTAL_IN1
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
REF_OUT
V
EE
OE_REF
M2
M1
M0
MR
SEL1
SEL0
CLK
XTAL_IN0
XTAL_OUT0
OSC
XTAL_OUT0
XTAL_IN1
00
11
Q
nQ
OSC
XTAL_OUT1
CLK
Pulldown
01
Phase
Detector
VCO
10
01
00
843001I-23
24-Lead TSSOP, E-Pad
4.4mm x 7.8mm x 0.925mm
package body
G Package
Top View
10
11
000
001
010
011
100
111
M
÷44
÷45
÷48
÷50
÷51
÷64
(default)
MR
Pulldown
M2:M0
Pullup
3
REF_OUT
OE_REF
Pulldown
843001I-23 Rev A 11/17/15
1
©2015 Integrated Device Technology, Inc.
843001I-23 DATA SHEET
Table 1. Pin Descriptions
Number
1
2, 3
4
5
6, 7
8, 23
9
10
11,
12
13,
14
15
16, 17
Name
V
CCO_LVCMOS
N0, N1
N2
V
CCO_LVPECL
Q, nQ
V
EE
V
CCA
V
CC
XTAL_OUT1,
XTAL_IN1
XTAL_OUT0,
XTAL_IN0
CLK
SEL0, SEL1
Power
Input
Input
Power
Output
Power
Power
Power
Input
Input
Input
Input
Pulldown
Pulldown
Pulldown
Pullup
Type
Description
Output supply pin for REF_CLK output.
Output divider select pins. LVCMOS/LVTTL interface levels. See Table 3C.
Output supply pin for LVPECL output.
Differential output pair. LVPECL interface levels.
Negative supply pins.
Analog supply pin.
Core supply pin.
Parallel resonant crystal interface.
XTAL_OUT1 is the output, XTAL_IN1 is the input.
Parallel resonant crystal interface.
XTAL_OUT0 is the output, XTAL_IN0 is the input.
Single-ended clock input. LVCMOS/LVTTL interface levels.
Input MUX select pins. LVCMOS/LVTTL interface levels. See Table 3D.
Active HIGH Master Reset. When logic HIGH, the internal dividers are reset
causing the true output Q to go low and the inverted output nQ to go high.
When logic LOW, the internal dividers and the outputs are enabled.
LVCMOS/LVTTL interface levels.
Feedback divider select pins. LVCMOS/LVTTL interface levels. See Table 3B.
Reference clock output enable. Default LOW. See Table 3E.
LVCMOS/LVTTL interface levels.
Reference clock output. LVCMOS/LVTTL interface levels.
18
MR
Input
Pulldown
19, 20, 21
22
24
M0, M1, M2
OE_REF
REF_OUT
Input
Input
Output
Pullup
Pulldown
NOTE:
Pullup and Pulldown
refer to internal input resistors. See Table 2,
Pin Characteristics,
for typical values.
Table 2. Pin Characteristics
Symbol
C
IN
R
PULLUP
R
PULLDOWN
R
OUT
Parameter
Input Capacitance
Input Pullup Resistor
Input Pulldown Resistor
Output Impedance
REF_OUT
V
CCO
= 3.3V
V
CCO
= 2.5V
Test Conditions
Minimum
Typical
4
51
51
21
25
Maximum
Units
pF
k
k
Rev A 11/17/15
2
FEMTOCLOCK® CRYSTAL/LVCMOS-TO-LVPECL/ LVCMOS
FREQUENCY SYNTHESIZER
843001I-23 DATA SHEET
Function Tables
Table 3A. Common Configuration Table
Input Frequency
(MHz)
27
24.75
19.44
19.44
19.44
25
25
25
25
25
25
25
25
25
25
25
25
M Feedback Divider
Value
44
48
64
64
64
50
50
50
50
50
45
48
48
48
51
51
51
VCO
Frequency
(MHz)
1188
1188
1244.16
1244.16
1244.16
1250
1250
1250
1250
1250
1125
1200
1200
1200
1275
1275
1275
N Output Divider
Value
16
16
8
2
4
10
8
5
4
2
6
12
8
16
12
8
6
Output Frequency (MHz)
74.25
74.25
155.52
622.08
311.04
125
156.25
250
312.5
625
187.5
100
150
75
106.25
159.375
212.5
Application
HDTV
HDTV
SONET
SONET
SONET
GigE
10 GigE
GigE
XGMII
10 GigE
12 GigE
PCI Express
SATA
SATA
Fibre Channel
10 Gig Fibre Channel
4 Gig Fibre Channel
Table 3B. Programmable M Feedback Divider Function Table
Inputs
M2
0
0
0
0
1
1
M1
0
0
1
1
0
0
M0
0
1
0
1
0
1
M Feedback Divider
Value
44
45
48
50
51
64 (default)
Input Frequency (MHz)
Minimum
25.5
24.9
23.3
22.4
22.0
19.44
Maximum
27
27
26.56
25.5
25
19.92
FEMTOCLOCK® CRYSTAL/LVCMOS-TO-LVPECL/ LVCMOS
FREQUENCY SYNTHESIZER
3
Rev A 11/17/15
843001I-23 DATA SHEET
Table 3C. Programmable N Output Divider Function Table
Inputs
N2
0
0
0
0
1
1
1
1
N1
0
0
1
1
0
0
1
1
N0
0
1
0
1
0
1
0
1
N Divider Value
2
4
5
6
8 (default)
10
12
16
Table 3D. Select Mode Function Table
Inputs
SEL1
0
0
1
1
SEL0
0
1
0
1
Reference Input
XTAL0
XTAL1
CLK
CLK
PLL Mode
Active (default)
Active
Active
Bypass
Table 3E. OE_REF Output Function Table
Input
OE_REF
0
1
Output
REF_OUT
High-Impedance (default)
Active
Rev A 11/17/15
4
FEMTOCLOCK® CRYSTAL/LVCMOS-TO-LVPECL/ LVCMOS
FREQUENCY SYNTHESIZER
843001I-23 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
XTAL_IN
Other Input
Outputs, I
O
(LVPECL)
Continuous Current
Surge Current
Outputs, V
O
(LVCMOS)
Package Thermal Impedance,
JA
Storage Temperature, T
STG
Rating
4.6V
0V to V
CC
-0.5V to V
CC
+ 0.5V
50mA
100mA
-0.5V to V
CCO_LVCMOS
+ 0.5V
32.1C/W (0 mps)
-65C to 150C
DC Electrical Characteristics
Table 4A. Power Supply DC Characteristics,
V
CC
= V
CCO_LVCMOS
= V
CCO_LVPECL
= 3.3V ± 5%, V
EE
= 0V,
T
A
= -40°C to 85°C
Symbol
V
CC
V
CCA
Parameter
Core Supply Voltage
Analog Supply Voltage
Test Conditions
Minimum
3.135
V
CC
– 0.11
3.135
Typical
3.3
3.3
3.3
Maximum
3.465
V
CC
3.465
140
Outputs Unterminated
11
Units
V
V
V
mA
mA
V
CCO_LVPECL,
Output Supply Voltage
V
CCO_LVCMOS
I
EE
I
CCA
Power Supply Current
Analog Supply Current
Table 4B. Power Supply DC Characteristics,
V
CC
= 3.3V ± 5%, V
CCO_LVCMOS
= V
CCO_LVPECL
= 2.5V ± 5%, V
EE
= 0V,
T
A
= -40°C to 85°C
Symbol
V
CC
V
CCA
Parameter
Core Supply Voltage
Analog Supply Voltage
Test Conditions
Minimum
3.135
V
CC
– 0.11
2.375
Typical
3.3
3.3
2.5
Maximum
3.465
V
CC
2.625
139
Outputs Unterminated
11
Units
V
V
V
mA
mA
V
CCO_LVPECL,
Output Supply Voltage
V
CCO_LVCMOS
I
EE
I
CCA
Power Supply Current
Analog Supply Current
FEMTOCLOCK® CRYSTAL/LVCMOS-TO-LVPECL/ LVCMOS
FREQUENCY SYNTHESIZER
5
Rev A 11/17/15
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