SM840002
ClockWorks™ Dual 10-Gigabit/Gigabit
Ethernet 62.5MHz, 125MHz, or 156.25MHz, Ultra-Low Jitter LVCMOS Clock Frequency Synthesizer
General Description
The SM840002 is a dual 10-Gigabit Ethernet and Gigabit Ethernet, 62.5MHz, 125MHz, or 156.25MHz LVCMOS 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. Power supplies of either 2.5V or 3.3V are supported, with superior jitter and phase-noise performance. The device synthesizes a 62.5MHz, 125MHz, or 156.25MHz, lownoise LVCMOS output pair for Ethernet applications. The crystal reference frequency is 25MHz. The SM840002 is an excellent replacement for IDT FemtoClocks®, with improved waveform integrity, and jitter. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com.
Features
• Generates two LVCMOS outputs • Operating supply modes: − Core/Output − 3.3V/3.3V, 2.5V/2.5V • Typical phase jitter @156.25MHz~64 fs (1.875MHz − 20MHz) • Crystal frequency: 25MHz • 62.5MHz, 125MHz, or 156.25MHz output frequency • Output Skew: 12ps (maximum) • Phase Noise @ 156.25MHz: − 1KHz: −126dBc/Hz − 10KHz: −130dBc/Hz − 100KHz: −126dBc/Hz − 1MHz: −139dBc/Hz − 10MHz: −165dBc/Hz − 20MHz: −166/dBc/Hz • Temperature range: –40°C to +75°C • Green-, RoHS-, and PFOS-compliant • Available in 16-pin TSSOP
Applications
• Gigabit Ethernet • 10-Gigabit Ethernet
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
November 2010
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Micrel, Inc.
SM840002
Block Diagram
Ordering Information(1)
Part Number SM840002KA SM840002KA
Notes: 1. 2. Devices are Green-, RoHS-, and PFOS-compliant. Tape and Reel.
Package Type K-16 TR
(2)
Operating Range
Package Marking 840002 840002
–40°C to +75°C –40°C to +75°C
K-16
Pin Configuration
16-Pin TSSOP (K-16)
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Micrel, Inc.
SM840002
Pin Description
Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Pin Name F_SEL0 nXTAL_SEL TEST_CLK OE NC nPLL_SEL VDDA VDD XTAL_OUT XTAL_IN VDDO Q1 Q0 GND GND F_SEL1 I P P O I P O O P P I Pull-up LVCMOS LVCMOS 12pF Crystal 12pF Crystal Pull-Down Type I I I I Level Pull-Up Pull-Down Pull-Down Pull-Up Pin Function Frequency Select Pin. LVCMOS interface levels. Selects between XTAL and TEST_CLK Reference Input. When HIGH, selects TEST_CLK. When LOW, selects XTAL inputs. LVCMOS interface levels. Single-Ended LVCMOS Clock Input. Output Enable. When HIGH, the outputs are active. When LOW, the outputs are in a high impedance state. LVCMOS interface levels. No Connect. Selects between the VCO reference and the VCO Output. When LOW, the output is driven from the VCO output. When HIGH, the PLL is bypassed. 2.5V or 3.3V Output Power Supply. No filter resistor needed. 2.5V or 3.3V Output Power Supply. Crystal Reference Output, no load caps needed. Crystal Reference Input, no load caps needed. 2.5V or 3.3V Output Power Supply. Single-Ended Output Clock. Single-Ended Output Clock. Ground. Ground. Frequency Select Pin. LVCMOS interface levels.
Configuring the SM840002
Xtal Frequency (MHz) 25 25 25 25 F_SEL1 0 0 1 1 F_SEL0 0 1 0 1 M Divider 125 130 130 130 N Divider 20 26 52 26 Output Frequency (MHz) 156.25 125 62.5 125
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Micrel, Inc.
SM840002
Absolute Maximum Ratings(1)
Supply Voltage (VDD)...................................................+4.6V Input Voltage (VIN) ................................ –0.50V to VDD+0.5V Output Voltage (VOUT) .......................... –0.50V to VDD+0.5V Lead Temperature (soldering, 20sec.)....................... 260°C Storage Temperature (Ts) .........................–65°C to +150°C
Operating Ratings(2)
Supply Voltage (VDDO) .......................... +2.375V to +3.465V Supply Voltage (VDD, VDDA) ................... +2.375V to +3.465V Ambient Temperature (TA) .......................... –40°C to +75°C Junction Thermal Resistance TSSOP (θJA)(Still Air).......................................127°C/W
DC Electrical Characteristics(3)
VDDA = VDD = 2.5V ±5%, VDDO = 2.5V ±5%, TA = –40°C to +75°C, unless noted. Symbol VDD VDDA VDDO IDD IDDA IDDO Parameter Core Supply Voltage Analog Supply Voltage Output Supply Voltage Core Supply Current Analog Supply Current Output Supply Current No Load Condition Min. 2.375 2.375 2.375 Typ. 2.50 2.50 2.50 0.1 48 15 Max. 2.625 2.625 2.625 1 55 23 Units V V V mA mA mA
VDDA = VDD = 3.3V ±5%, VDDO = 3.3V ±5%, TA = –40°C to +75°C, unless noted. Symbol VDD VDDA VDDO IDD IDDA IDDO
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. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
Parameter Core Supply Voltage Analog Supply Voltage Output Supply Voltage Core Supply Current Analog Supply Current Power Supply Current
Condition
Min. 3.135 3.135 3.135
Typ. 3.30 3.30 3.30 0.1 49
Max. 3.465 3.465 3.465 1 55 32
Units V V V mA mA
No Load
25
2. 3.
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Micrel, Inc.
SM840002
LVCMOS DC Electrical Characteristics(3)
VDDA = VDD =2.5V or 3.3V ±5%, VDDO = 2.5V or 3.3V ±5%, TA = –40°C to +75°C, unless noted. Symbol VIH VIL Parameter Input HIGH Voltage Input LOW Voltage OE, F_SEL0, F_SEL1 IIH Input HIGH Current nPLL_SEL, MR, nXTAL_SEL, TEST_CLK OE, F_SEL0, F_SEL1 IIL Input LOW Current nPLL_SEL, MR, nXTAL_SEL, TEST_CLK VDD = VIN =3.465V or 2.625V VDD = VIN =3.465V or 2.625V VDD = 3.465V or 2.625V VIN = 0V VDD = 3.465V or 2.625V VIN = 0V VDDO = 3.3V ±5% VDDO = 2.5V ±5% VDDO = 3.3V ±5% or 2.5V ±5% −150 −5 2.6 1.8 0.5 Condition Min. 2 −0.30 Typ. Max. VDD + 0.3 0.80 5 150 Units V V µA µA µA µA V V V
VOH VOL
Output HIGH Voltage(4) Output LOW Voltage(4)
AC Electrical Characteristics(5)
VDDA = VDD =2.5V or 3.3V ±5%, VDDO = 2.5V or 3.3V ±5%, TA = –40°C to +75°C, unless noted. Symbol FOUT FOUT FOUT FOUT tSKEW tJITTER tJITTER tJITTER tR/tF ODC
Notes: 4. 5. 6. Outputs terminated with 50Ω to VDD/2. See Parameters measurements 3.3V load test circuit. The circuit is designed to meet the AC specifications shown in the above table(s) after thermal equilibrium has been established. Defined as skew between outputs at the same supply voltage and with equal load conditions; Measured at the output differential crossing points.
Parameter Output Frequency Output Frequency Output Frequency Output Frequency Output Skew
(6)
Condition F_SEL[1:0] = 00 F_SEL[1:0] = 01 F_SEL[1:0] = 10 F_SEL[1:0] = 11 156.25MHz 125MHz 62.5MHz 20% to 80%
Min.
Typ. 156.25 125 62.5 125
Max.
Units MHz MHz MHz MHz
12 0.064 0.065 0.077 100 48 50 350 52
ps ps ps ps ps %
RMS Phase Jitter RMS Phase Jitter RMS Phase Jitter Output Rise/ Fall Time Output Duty Cycle
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SM840002
Crystal Characteristics
Parameter Mode of Oscillation Frequency Equivalent Series Resistance (ESR) Shunt Capacitor, C0 Correlation Drive Level Condition 12pF Load Min. Typ. Max. Units MHz Ω pF uW Fundamental, Parallel Resonant 25 50 3 7 100 300
Phase Noise Plot: 62.5MHz @ 3.3V
Phase Noise Plot: 125MHz @ 3.3V
Phase Noise Plot: 156.25MHz @ 3.3V
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Micrel, Inc.
SM840002
Figure 1. Duty Cycle Timing
Figure 2. All Outputs Rise/Fall Time
Figure 3. RMS Phase Noise/Jitter
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Micrel, Inc.
SM840002
Figure 4. LVCMOS Output Load and Test Circuit
Figure 5. Crystal Input Interface
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M9999-110810 hbwhelp@micrel.com or (408) 955-1690
Micrel, Inc.
SM840002
Package Information
16-Pin TSSOP (K-16)
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.
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