SM843251-156 [MICREL]
ClockWorks? 10-Gigabit Ethernet, 156.25MHz, Ultra-Low Jitter LVPECL Clock Frequency Synthesizer; 发条？万兆以太网， 156.25MHz ，超低抖动LVPECL时钟频率合成器
| 型号： | SM843251-156 |
| 厂家： | 
MICREL SEMICONDUCTOR |
| 描述： | ClockWorks? 10-Gigabit Ethernet, 156.25MHz, Ultra-Low Jitter LVPECL Clock Frequency Synthesizer |
| 文件： | 总7页 (文件大小：320K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SM843251-156
ClockWorks™ 10-Gigabit Ethernet,
156.25MHz, Ultra-Low Jitter LVPECL Clock
Frequency Synthesizer
General Description
Features
The SM843251-156 is a 10-Gigabit Ethernet, 156.25MHz
LVPECL clock frequency synthesizer and a member of the
ClockWorks™ family of devices from Micrel. It provides a
low-noise timing solution for high-speed, high-accuracy
synthesis of clock signals. It includes a patented
RotaryWave® architecture that provides a very stable clock
with very low noise.
• Generates a low-noise 156.25MHz LVPECL output
• 2.5V or 3.3V operating voltage
• Typical phase jitter @156.25MHz~110fs
(1.875MHz − 20MHz)
• Crystal frequency: 25MHz
• 156.25MHz output frequency
• Phase Noise @ 156.25MHz:
Power supplies of either 2.5V or 3.3V are supported, with
superior jitter and phase noise performance. The device
synthesizes a 156.25MHz, low-noise, LVPECL output for
Ethernet applications. The crystal reference frequency is
25MHz.
− 1kHz:
−123dBc/Hz
− 10kHz: −130dBc/Hz
− 100kHz: −135dBc/Hz
− 1MHz:
−140dBc/Hz
The SM843251-156 is an excellent replacement for IDT
FemtoClocks®, with improved waveform integrity, and
jitter.
− 10MHz: −161dBc/Hz
− 20MHz: −166/dBc/Hz
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
• Industrial temperature range
• Green-, RoHS-, and PFOS-compliant
• Available in 8-pin TSSOP
Applications
• Gigabit Ethernet
• 10-Gigabit Ethernet
_______________________________________________________________________________________________________
Block Diagram
ClockWorks is a trademark of Micrel, Inc.
RotaryWave is a registered trademark of Multigig, Inc.
FemtoClocks is a registered trademark of IDT, 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
M9999-100110-A
hbwhelp@micrel.com or (408) 955-1690
October 2010
Micrel, Inc.
SM843251-156
Ordering Information(1)
Part Number
SM843251-156KA
SM843251-156KA TR(2)
Notes:
Package Type
Operating Range
Industrial
Package Marking
K-8
K-8
843251-156
843251-156
Industrial
1. Devices are Green-, RoHS-, and PFOS-compliant.
2. Tape and Reel.
Pin Configuration
8-Pin TSSOP (K-8)
Pin Description
Pin Number
Pin Name
VDDA
Type
PWR
Level
Pin Function
1
2
3
4
5
6
7
8
Analog 2.5V or 3.3V Power Supply. No filter resistor needed.
Ground.
VEE
PWR
XTAL_OUT
XTAL_IN
NC
O, (SE)
I, (SE)
−
12pF crystal
12pF crystal
Crystal Reference Output, no load caps needed.
Crystal Reference Input, no load caps needed.
No Connect
/Q0
O, (DIF)
O, (DIF)
PWR
LVPECL
LVPECL
Differential Clock Output
Q0
Differential Clock Output
VDD
2.5V or 3.3V Power Supply
M9999-100110-A
hbwhelp@micrel.com or (408) 955-1690
October 2010
2
Micrel, Inc.
SM843251-156
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VDDA, VDD,) ........................................+4.6V
Supply Voltage (VDD, VDDA)........................+2.375 to +3.465
Ambient Temperature (TA) ..........................–40°C to +85°C
Junction Thermal Resistance
Input Voltage (VIN)...............................−0.50V to VDD + 0.5V
LVPECL Output Current (IOUT
)
Continuous............................................................50mA
Surge ..................................................................100mA
Lead Temperature (soldering, 20sec.)....................... 260°C
Case Temperature ..................................................... 115°C
Storage Temperature (Ts) .........................−65°C to +150°C
TSSOP (θJA)(Still Air).......................................141°C/W
DC Electrical Characteristics(3)
VDD = VDDA = 3.3V ±5%; TA = –40°C to +85°C, unless noted.
Symbol
VDD
Parameter
Core Supply Voltage
Analog Supply Voltage
Analog Supply Current
Total Supply Current
Condition
Min.
3.135
3.135
Typ.
3.30
3.30
50
Max.
3.465
3.465
60
Units
V
VDDA
IDDA
V
Included in IEE
No load
mA
mA
IEE
88
110
VDD = VDDA = 2.5V ±5%; TA = –40°C to +85°C, unless noted.
Symbol
VDD
Parameter
Condition
Min.
2.375
2.375
Typ.
2.50
2.50
50
Max.
2.625
2.625
60
Units
V
Core Supply Voltage
Analog Supply Voltage
Analog Supply Current
Total Supply Current
VDDA
IDDA
V
Included in IEE
No load
mA
mA
IEE
80
100
LVPECL DC Electrical Characteristics(3, 4)
VDD = VDDA = 2.5V ±5% or 3.3V ±5%, TA = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
VOH
Output High Voltage
50Ω to VDD − 2V
V
DD – 1.145
DD – 1.945
0.6
VDD – 0.97
VDD – 1.77
0.8
VDD – 0.845
VDD – 1.645
1.0
V
V
V
VOL
Output Low Voltage
50Ω to VDD − 2V
V
VSWING
Peak-to-Peak Output Voltage Swing
Notes:
1. Permanent device damage may occur if absolute maximum ratings are exceeded. This is a stress rating only and functional operation is not implied
at conditions other than those detailed in the operational sections of this data sheet. Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
3. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established with a transverse
airflow greater than 500 lfpm.
4. See Figure 4 for load test circuit example.
M9999-100110-A
hbwhelp@micrel.com or (408) 955-1690
October 2010
3
Micrel, Inc.
SM843251-156
AC Electrical Characteristics(5)
VDD = VDDA = 2.5V ±5% or 3.3V ±5%, TA = –40°C to +85°C, unless noted.
Symbol Parameter
Condition
Min.
Typ.
Max. Units
FOUT
Output Frequency
25MHz Crystal
156.25
MHz
fs
RMS Phase Jitter (Output = 156.25 MHz)
tJITTER
tR / tF
ODC
Integration Range: 1.875MHz to 20MHz
20% to 80%
110
175
50
Output Rise/Fall Time
Output Duty Cycle
80
48
350
52
ps
%
Note:
5. The circuit is designed to meet the AC specifications shown in the above table(s) after thermal equilibrium has been established with a transverse
airflow greater than 500 lfpm.
Crystal Characteristics
Parameter
Condition
Min.
Typ.
Max.
Units
Mode of Oscillation
Frequency
12pF Load
Fundamental, Parallel Resonant
25
MHz
Ω
Equivalent Series Resistance (ESR)
Shunt Capacitor, C0
Correlation Drive Level
50
3
7
pF
100
300
uW
M9999-100110-A
hbwhelp@micrel.com or (408) 955-1690
October 2010
4
Micrel, Inc.
SM843251-156
Figure 1. Duty Cycle Timing
Figure 2. All Outputs Rise/Fall Time
Figure 3. RMS Phase Noise/Jitter
M9999-100110-A
hbwhelp@micrel.com or (408) 955-1690
October 2010
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Micrel, Inc.
SM843251-156
Figure 4. LVPECL Output Load and Test Circuit
Figure 5. Crystal Input Interface
M9999-100110-A
hbwhelp@micrel.com or (408) 955-1690
October 2010
6
Micrel, Inc.
SM843251-156
Package Information
8-Pin TSSOP (K-8)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This
information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry,
specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability
whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties
relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant
into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A
Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2010 Micrel, Incorporated.
M9999-100110-A
hbwhelp@micrel.com or (408) 955-1690
October 2010
7
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