SM843256KA [MICREL]
10 Gigabit Ethernet and SONET, 6 output, Ultra-Low Jitter LVPECL Frequency Synthesizer; 10千兆以太网和SONET , 6输出,超低抖动LVPECL频率合成器型号: | SM843256KA |
厂家: | MICREL SEMICONDUCTOR |
描述: | 10 Gigabit Ethernet and SONET, 6 output, Ultra-Low Jitter LVPECL Frequency Synthesizer |
文件: | 总8页 (文件大小:233K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
SM843256
10 Gigabit Ethernet and SONET, 6 output,
Ultra-Low Jitter LVPECL Frequency
Synthesizer
General Description
Features
The SM843256 provides a low-noise timing solution for
high speed, high accuracy synthesis of clock signals.
Common applications include SONET, Gigabit Ethernet,
10 Gigabit Ethernet, and similar networking standards. It
includes a unique power reduction methodology, along
with a patented RotaryWaveTM architecture that provides a
very stable clock with very low noise.
• Generates six LVPECL outputs
• 2.5V or 3.3V operating range
• Typical phase jitter @ 156.25MHz
(1.875MHz to 20MHz): 80fs (typical) @ 3.3V
• 75MHz to 625MHz output frequencies
• Industrial temperature range
• Green, RoHS, and PFOS compliant
• Available in 24-pin TSSOP EPAD
• Operating supply modes:
Power supplies of either 3.3V or 2.5V are supported, with
superior jitter and phase noise performance. The device
synthesizes different low noise LVPECL output
frequencies such as 125MHz, 156.25MHz, 312.5MHz, and
625MHz for Ethernet applications; 77.76MHz, 155.52MHz,
311.04MHz, and 622.08MHz for SONET applications. The
crystal reference frequencies used include 25MHz and
19.44Mhz for Ethernet and SONET applications,
respectively.
Core/Output
3.3V/3.3V, 3.3V/2.5V, 2.5V/2.5V
Applications
• SONET
The SM843256 is an excellent replacement for IDT Femto-
clocks, with improved accuracy, power consumption,
waveform integrity, and jitter.
• Gigabit Ethernet
• 10-Gigabit Ethernet
• Infiniband
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
________________________________________________________________________________________________________________________
Block Diagram
RotaryWave is a 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
M9999-072110-B
July 2010
Micrel, Inc.
SM843256
Ordering Information(1, 2)
Part Number
SM843256KA
Notes:
Marking
843256
Shipping
Junction Temperature Range
Package
24-Pin TSSOP EPAD
Tube, Tape & Reel
–40° to +85°C
1. Devices are Green, RoHS, and PFOS Compliant.
2. Lead finish is 100% matte tin.
Pin Configuration
24-Pin TSSOP EPAD
(Top View)
M9999-072110-B
July 2010
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Micrel, Inc.
SM843256
Pin Description
Pin Number
1, 2
Pin Name
VDDO
Pin Type
PWR
Pin Level
Pin Function
2.5V or 3.3V Power Supply
Differential Clock Output
Differential Clock Output
Differential Clock Output
Pull-Up 45k, Single-Ended Input Select Pin.
Logic (0) = PLL Output
3, 4
/Q2, Q2
/Q1, Q1
/Q0, Q0
O, (DIF)
O, (DIF)
O, (DIF)
LVPECL
LVPECL
LVPECL
5, 6
7, 8
9
PLL_BYPASS
I, (SE)
LVCMOS
Logic (1) = Xtal Reference
Analog 3.3V or 2.5V Power Supply
3.3V or 2.5V Power Supply
10
11
VDDA
VDD
PWR
PWR
12
FB_SEL
XTAL_IN
XTAL_OUT
N_SEL0
GND
I, (SE)
I, (SE)
O, (SE)
I, (SE)
PWR
LVCMOS
12pF crystal
12pF crystal
LVCMOS
Pull-Down 45k, Single-Ended Input Select Pin
Crystal Reference Input, no load caps needed.
Crystal Reference Output, no load caps needed.
Pull-Up 45k, Single-Ended Input Select Pin
Ground
13
14
15
16, 17
18
N_SEL1
/Q5, Q5
/Q4, Q4
/Q3, Q3
I, (SE)
O, (DIF)
O, (DIF)
O, (DIF)
LVCMOS
LVPECL
LVPECL
LVPECL
Pull-Up 45k, Single-Ended Input Select Pin
Differential Clock Output
19, 20
21, 22
23, 24
Differential Clock Output
Differential Clock Output
Input and Output Frequency Table
XTAL (MHz)
FB_SEL
N_SEL1
N_SEL0
Outputs (MHz)
Application
24
24
24
24
0
0
0
0
0
0
1
1
0
1
0
1
600
-
300
150
120
-
SAS/SATA
-
25
25
25
25
0
0
0
0
0
0
1
1
0
1
0
1
625
312.50
156.25
125
10 Gigabit Ethernet
10 Gigabit Ethernet
10 Gigabit Ethernet
Gigabit Ethernet/Infiniband/PCI/PCI-E/PCI-X
18.75
18.75
18.75
18.75
1
1
1
1
0
0
1
1
0
1
0
1
600
300
150
75
-
-
SAS/SATA
SAS/SATA
19.44
19.44
19.44
19.44
1
1
1
1
0
0
1
1
0
1
0
1
622.08
311.04
155.52
77.76
10 Gigabit Ethernet/SONET
SONET
SONET
SONET
19.53125
19.53125
19.53125
19.53125
1
1
1
1
0
0
1
1
0
1
0
1
625
10 Gigabit Ethernet
10 Gigabit Ethernet
10 Gigabit Ethernet
10 Gigabit Ethernet
312.5
156.25
78.125
M9999-072110-B
July 2010
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Micrel, Inc.
SM843256
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VDDA, VDD, VDDO)................................+4.6V
Input Voltage (VIN)………………………-0.50V to VDD+0.5V
Supply Voltage (VDDO).......................... +2.375V to +3.465V
Supply Voltage (VDD, VDDA)................... +2.375V to +3.465V
Ambient Temperature (TA) ..........................–40°C to +85°C
LVPECL Output Current ( IOUT
)
Junction Thermal Resistance(3)
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).........................................32°C/W
DC Electrical Characteristics(4)
VDDA = VDD = 3.3V ±5% or 2.5V ±5%, VDDO = 2.5V ±5%, TA = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min
Typ
2.5
3.3
55
Max
2.625
3.465
65
Units
V
VDDO
2.5V Operating Voltage
2.375
2.375
VDDA,VDD 3.3V Operating Voltage
V
IDDA
Analog Supply Range
Core Supply Current
I/O Supply Range
FOUT = 156.25MHz
FOUT = 625.00MHz
FOUT = 156.25MHz
mA
56
IDD
13
17
mA
mA
F
OUT = 625.00MHz
13
IDDO
FOUT = 156.25MHz
FOUT = 625.00MHz
235
330
TBD
VDDA = VDD = VDDO = 3.3V ±5%, TA = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min
Typ
Max
Units
VDDA
,
3.3V Operating Voltage
3.135
3.3
3.465
V
VDD
,
VDDO
IDDA
Analog Supply Range
Core Supply Current
I/O Supply Range
FOUT = 156.25MHz
FOUT = 625.00MHz
FOUT = 156.25MHz
FOUT = 625.00MHz
FOUT = 156.25MHz
FOUT = 625.00MHz
55
56
65
17
mA
mA
mA
IDD
13
13
IDDO
256
366
282
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. Package thermal resistance assumes exposed pad is soldered (or equivalent) to the devices most negative potential on the PCB.
4. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
M9999-072110-B
July 2010
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Micrel, Inc.
SM843256
LVPECL DC Electrical Characteristics(5, 6)
VDDA = VDD = 3.3V ±5% or 2.5V ±5%, VDDO = 2.5V 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 VDDO-2V
VDDO
VDDO
VDDO
V
–1.145
–0.97
–0.845
VOL
Output Low Voltage
50Ω to VDDO-2V
VDDO
–1.945
VDDO
–1.77
VDDO
–1.645
V
V
VSWING
Peak-to-Peak Output Voltage Swing
Figure 1
0.6
0.8
1.0
LVCMOS DC Electrical Characteristics(6)
VDDA = VDD = 3.3V ±5% or 2.5V ±5%, VDDO = 2.5V or 3.3V ±5%, TA = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min
Typ
Max
Units
VIH
Input High Voltage
2
VDD
V
+0.3
VIL
IIH
IIH
Input Low Voltage
-0.3
0.8
150
5
V
Input High Current (FB_SEL)
VDD = VIN = 3.465V
VDD = VIN = 3.465V
μA
μA
Input High Current (PLL_BYPASS),
(N_SEL0), (NSEL1)
IIL
IIL
Input Low Current (FB_SEL)
VDD = 3.465V, VIN = 0V
VDD = 3.465V, VIN = 0V
-5
μA
μA
Input Low Current (PLL_BYPASS),
(N_SEL0), (NSEL1)
-150
AC Electrical Characteristics(7)
VDDA = VDD = 3.3V ±5% or 2.5V ±5%, VDDO = 2.5V or 3.3V ±5%, TA = –40°C to +85°C, unless noted.
Symbol
FOUT
Parameter
Condition
Min
75
Typ
Max
625
350
54
Units
MHz
ps
Output Frequency
LVPECL Output Rise/Fall Time
Output Duty Cycle
Output-to-Output Skew
PLL Lock Time
Refer to Frequency Table
20% – 80%
TR/TF
ODC
100
46
175
50
%
TSKEW
TLOCK
Tjit(∅)
Note 8
45
ps
20
ms
fs
RMS Phase Jitter (Output = 156.25 MHz) Integration Range (12kHz – 20MHz)
Integration Range (1.875MHz – 20MHz)
251
80
fs
Notes:
5. See Figure 4 for load test circuit example.
6. The circuit is designed to meet the DC specifications shown in the above table(s) after thermal equilibrium has been established.
7. The circuit is designed to meet the AC specifications shown in the above table(s) after thermal equilibrium has been established.
8. Defined as skew between outputs at the same supply voltage and with equal load conditions; Measured at the output differential crossing points.
M9999-072110-B
July 2010
5
Micrel, Inc.
SM843256
RMS Phase Jitter (Random)
1.875MHz to 20MHz = 80fs (Typical)
Noise Power
dBc/Hz
Offset Frequency (Hz)
Phase Noise Plot: 156.25MHz @ 3.3V
Figure 1. Duty Cycle Timing
Figure 2. All Outputs Rise/Fall Time
M9999-072110-B
July 2010
6
Micrel, Inc.
SM843256
Figure 3. RMS Phase Noise/Jitter
Figure 4. LVPECL Output Load and Test Circuit
Figure 5. Crystal Input Interface
M9999-072110-B
July 2010
7
Micrel, Inc.
SM843256
Package Information
24-pin EPAD TSSOP
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
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its
use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
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.
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