SM802128
ClockWorks
ΤΜ
10GbE Octal 156.25MHz,
312.5MHz, Ultra-Low Jitter, LVPECL
Frequency Synthesizer
General Description
Features
•
Generates eight LVPECL clocks at 156.25MHz or
The SM802128 is a member of the ClockWorks™ family of
312.5MHz
devices from Micrel and provides an extremely low-noise
timing solution for 10GbE Ethernet clock signals. It is
•
2.5V or 3.3V operating range
based upon a unique patented RotaryWave
®
architecture
•
Typical phase jitter @ 156.25MHz
that provides very low phase noise.
(1.875MHz to 20MHz): 110fs with crystal reference
The device operates from a 3.3V or 2.5V power supply
•
Industrial temperature range (–40°C to +85°C)
and synthesizes eight LVPECL output clocks at
•
Green, RoHS, and PFOS compliant
156.25MHz or 312.5MHz. The SM802128 accepts a 25
MHz crystal or LVCMOS reference clock.
•
Available in 44-pin 7mm
×
7mm QFN package
Data sheet and support documentation can be found on
Micrel’s web site at:
www.micrel.com.
________________________________________________________________________________________________________
Block Diagram
ClockWorks is a trademark of Micrel, Inc
RotaryWave is a registered trademark of Multigig, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
408
) 944-0800 • fax + 1 (408) 474-1000 •
http://www.micrel.com
January 2012
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SM802128
Ordering Information
(1)
Part Number
SM802128UMG
SM802128UMGTR
Note:
1.
Devices are Green, RoHS, and PFOS compliant.
Marking
802128
802128
Shipping
Tray
Tape and Reel
Temperature Range
–40°C to +85°C
–40°C to +85°C
Package
44-Pin QFN
44-Pin QFN
Pin Configuration
44-Pin QFN
(Top View)
Pin Description
Pin Number
25, 26
28, 29
32, 33
35, 36
41, 42
1, 2
4, 5
7, 8
31, 37, 38
43, 44, 16
24, 39
Pin Name
/Q1, Q1
/Q2, Q2
/Q3, Q3
/Q4, Q4
/Q5, Q5
/Q6, Q6
/Q7, Q7
/Q8, Q8
VDDO1
VDDO2
VSSO1
PWR
PWR
PWR
Power Supply for the Outputs on Bank 1.
Power Supply for the Outputs on Bank 2.
Power Supply Ground for the Outputs on Bank 1.
O, (DIF)
LVPECL
Differential Clock Outputs from Bank 2 (156.25MHz or
312.5MHz).
O, (DIF)
LVPECL
Differential Clock Outputs from Bank 1 (156.25MHz or
312.5MHz).
Pin Type
Pin Level
Pin Function
January 2012
2
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SM802128
Pin Description (continued)
Pin Number
3, 6, 40
11, 20, 27, 30,
34
12, 13
21, 23
17
18
19
15
22
Pin Name
VSSO2
TEST
VDD
VSS
(Exposed
Pad)
REF_IN
XTAL_IN
XTAL_OUT
OE1
OE2
PWR
I, (SE)
I, (SE)
O, (SE)
I, (SE)
I, (SE)
LVCMOS
Crystal
Crystal
LVCMOS
LVCMOS
PWR
Pin Type
PWR
Pin Level
Pin Function
Power Supply Ground for the Outputs on Bank 2
Factory Test Pins. Do not connect anything to these pins.
Core Power Supply
Core Power Supply Ground. The exposed pad must be
connected to the VSS ground plane.
Reference Clock Input
Crystal Reference Input, no load caps needed (See Figure 5).
Crystal Reference Output, no load caps needed (See Figure
5).
Output Enable, Q1-Q4 disables to tri-state, 0 = Disabled, 1 =
Enabled, 45KΩ Pull-Up.
Output Enable, Q5-Q8 disables to tri-state, 0 = Disabled, 1 =
Enabled, 45KΩ Pull-Up.
PLL Bypass, Selects Output Source
0 = Normal PLL Operation
1 = Output from Input Reference Clock or Crystal
45KΩ Pull-Down
10
14
XTAL_SEL
FSEL
I, (SE)
I, (SE)
LVCMOS
LVCMOS
Selects PLL Input Reference Source
0 = REF_IN, 1 = XTAL, 45KΩ Pull-Up
Frequency Select, 1 = 156.25MHz, 0 = 312.5MHz,
45KΩ Pull-Up
9
PLL_BYPASS
I, (SE)
LVCMOS
Truth Tables
OE1/2
0
1
Tri-state
LVPECL
FSEL
0
1
Output Frequency (MHz)
312.5
156.25
PLL_BYPASS/CSB
0
1
−
−
XTAL_SEL
−
−
0
1
−
−
REF_IN
XTAL
PLL
XTAL/REF_IN
−
−
January 2012
3
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SM802128
Absolute Maximum Ratings
(1)
Supply Voltage (V
DD
, V
DDO1/2
) ……....................+4.6V
Input Voltage (V
IN
)……….…….…-0.50V to V
DD
+0.5V
Lead Temperature (soldering, 20sec.)…………260°C
Case Temperature……………………………….115°C
Storage Temperature (T
s
)…………...-65°C to +150°C
Operating Ratings
(2)
Supply Voltage (V
DD,
V
DDO1/2
) ............... +2.375V to +3.465V
Ambient Temperature (T
A
) .......................... –40°C to +85°C
(3)
Junction Thermal Resistance
QFN (θ
JA
)
Still-Air ............................................................... 24°C/W
QFN (ψ
JB
)
Junction-to-Board ................................................ 8°C/W
DC Electrical Characteristics
(4)
V
DD
= V
DDO1/2
= 3.3V
±5%
or 2.5V
±5%
V
DD
= 3.3V
±5%,
V
DDO1/2
= 3.3V
±5%
or 2.5V
±5%
T
A
= -40°C to
+85°C.
Symbol
V
DD
, V
DDO1/2
V
DD
, V
DDO1/2
I
DD
Parameter
2.5V Operating Voltage
3.3V Operating Voltage
Supply current V
DD
+ V
DDO
Outputs open
Condition
Min.
2.375
3.135
Typ.
2.5
3.3
220
275
Max.
2.625
3.465
275
345
Units
V
V
mA
V
DDO1
=V
DDO2
V
DDO1
=V
DDO2
156.25MHz
312.5MHz
LVPECL DC Electrical Characteristics
(4)
V
DD
= V
DDO1/2
= 3.3V
±5%
or 2.5V
±5%
V
DD
= 3.3V
±5%,
V
DDO1/2
= 3.3V
±5%
or 2.5V
±5%
T
A
=
−40°C
to
+85°C.
R
L
= 50Ω to V
DDO
-2V
Symbol
V
OH
V
OL
V
SWING
Parameter
Output High Voltage
Output Low Voltage
Output Voltage Swing
Condition
Min.
V
DDO
– 1.145
V
DDO
– 1.945
0.6
Typ.
V
DDO
– 0.97
V
DDO
– 1.77
0.8
Max.
V
DDO
– 0.845
V
DDO
– 1.645
1.0
Units
V
V
V
LVCMOS (PLL_BYPASS, XTAL_SEL, OE1, OE2, FSEL) DC Electrical Characteristics
(4)
V
DD
= 3.3V
±5%,
or 2.5V
±5%,
T
A
=
−40°C
to
+85°C.
Symbol
Parameter
Condition
Min.
2
−0.3
Typ.
Max.
V
DD
+ 0.3
0.8
150
−150
Units
V
V
μA
μA
V
IH
V
IL
I
IH
I
IL
Input High Voltage
Input Low Voltage
Input High Current
Input Low Current
V
DD
= V
IN
= 3.465V
V
DD
= 3.465V, V
IN
= 0V
January 2012
4
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SM802128
REF_IN DC Electrical Characteristics
(4)
V
DD
= 3.3V
±5%,
or 2.5V
±5%,
T
A
= -40°C to
+85°C.
Symbol
V
IH
V
IL
I
IN
Parameter
Input High Voltage
Input Low Voltage
Input Current
XTAL_SEL = V
IL
, V
IN
= 0V to V
DD
XTAL_SEL = V
IH
, V
IN
= V
DD
Condition
Min.
1.1
−0.3
−5
20
Typ.
Max.
V
DD
+ 0.3
0.6
5
Units
V
V
μA
µA
Crystal Characteristics
Parameter
Mode of Oscillation
Frequency
Equivalent Series Resistance (ESR)
Shunt Capacitor, C0
Correlation Drive Level
Condition
10pF Load
Min.
Typ.
Max.
Units
MHz
Ω
pF
uW
Fundamental, Parallel Resonant
25
1
10
50
5
100
January 2012
5
hbwhelp@micrel.com
or (408) 955-1690
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