SM843031-01 ClockWorks™ 10-Gigabit Ethernet, 312.5MHz, Ultra-Low Jitter LVPECL Clock Frequency Synthesizer General Description Features The SM843031-01 is a 10-Gigabit Ethernet, 312.5MHz 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. Power supplies of either 2.5V or 3.3V are supported, with superior jitter and phase noise performance. The device synthesizes a 312.5MHz, low-noise, LVPECL output for Ethernet applications. The crystal reference frequency used is 25MHz. The SM843031-01 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. • Generates a low noise LVPECL output • 2.5V or 3.3V operating range • Typical phase jitter @ 312.5MHz (1.875MHz to 20MHz): 119 fs (typical) @ 3.3V • Crystal frequency: 25MHz • 312.5MHz Output frequency • 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 October 2010 M9999-100110-A [email protected] or (408) 955-1690 Micrel, Inc. SM843031-01 Ordering Information(1) Part Number Package Type Operating Range Package Marking K-8 Industrial 843031-01 K-8 Industrial 843031-01 SM843031-01KA (2) SM843031-01KA TR Notes: 1. Devices are Green-, RoHS-, and PFOS-compliant. 2. Tape and Reel. Pin Configuration 8-Pin TSSOP (K-8) (Top View) Pin Description Pin Number Pin Name Pin Type 1 VDDA PWR Analog 2.5V or 3.3V Power Supply. No filter resistor needed. 2 VEE PWR Ground. 3 XTAL_OUT O, (SE) 12pF crystal Crystal Reference Output, no load caps needed. 4 XTAL_IN I, (SE) 12pF crystal Crystal Reference Input, no load caps needed. 5 NC − 6 /Q0 O, (DIF) LVPECL Differential Clock Output 7 Q0 O, (DIF) LVPECL Differential Clock Output 8 VDD PWR October 2010 Pin Level Pin Function No Connect 2.5V or 3.3V Power Supply 2 M9999-100110-A [email protected] or (408) 955-1690 Micrel, Inc. SM843031-01 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VDDA, VDD,) ........................................+4.6V 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 Supply Voltage (VDD, VDDA) ................... +2.375V to +3.465V Ambient Temperature (TA) .......................... –40°C to +85°C Junction Thermal Resistance 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 Parameter Condition Min. Typ. Max. Units 3.135 3.30 3.465 V 3.135 VDD Core Supply Voltage VDDA Analog Supply Voltage 3.30 3.465 V IDDA Analog Supply Current Included in IEE 50 60 mA IEE Total Supply Current No load 95 115 mA VDD = VDDA = 2.5V ±5%; TA = –40°C to +85°C, unless noted. Symbol Parameter Min. Typ. Max. Units VDD Core Supply Voltage Condition 2.375 2.50 2.625 V VDDA Analog Supply Voltage 2.375 2.50 2.625 V IDDA Analog Supply Current Included in IEE 50 60 mA IEE Total Supply Current No load 87 105 mA 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 VDD – 1.145 VDD – 0.97 VDD – 0.845 V VOL Output Low Voltage 50Ω to VDD-2V VDD – 1.945 VDD – 1.77 VDD – 1.645 V VSWING Peak-to-Peak Output Voltage Swing 0.6 0.8 1.0 V 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. October 2010 3 M9999-100110-A [email protected] or (408) 955-1690 Micrel, Inc. SM843031-01 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. FOUT Output Frequency tJITTER RMS Phase Jitter (Output = 312.5 MHz) Integration Range: 1.875MHz to 20MHz tR, tF Output Rise/Fall Time 20% to 80% ODC Output Duty Cycle Typ. Max. Units 312.5 MHz 119 fs 80 175 350 ps 48 50 52 % 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 Mode of Oscillation 12pF Load Min. Typ. Frequency 25 Equivalent Series Resistance (ESR) Units MHz 50 Shunt Capacitor, C0 Correlation Drive Level October 2010 Max. Fundamental, Parallel Resonant 4 Ω 3 7 pF 100 300 uW M9999-100110-A [email protected] or (408) 955-1690 Micrel, Inc. SM843031-01 Figure 1. Duty Cycle Timing Figure 2. All Outputs Rise/Fall Time Figure 3. RMS Phase Noise/Jitter October 2010 5 M9999-100110-A [email protected] or (408) 955-1690 Micrel, Inc. SM843031-01 Figure 4. LVPECL Output Load and Test Circuit Figure 5. Crystal Input Interface October 2010 6 M9999-100110-A [email protected] or (408) 955-1690 Micrel, Inc. SM843031-01 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. October 2010 7 M9999-100110-A [email protected] or (408) 955-1690