SM843251-156

SM843251-156 ClockWorks™ 10-Gigabit Ethernet, 156.25MHz, Ultra-Low Jitter LVPECL Clock Frequency Synthesizer General Description 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. 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. The SM843251-156 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 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: − 1kHz: −123dBc/Hz − 10kHz: −130dBc/Hz − 100kHz: −135dBc/Hz − 1MHz: −140dBc/Hz − 10MHz: −161dBc/Hz − 20MHz: −166/dBc/Hz • 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 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM843251-156 Ordering Information(1) Part Number SM843251-156KA SM843251-156KA TR Notes: 1. 2. Devices are Green-, RoHS-, and PFOS-compliant. Tape and Reel. (2) Package Type K-8 K-8 Operating Range Industrial Industrial Package Marking 843251-156 843251-156 Pin Configuration 8-Pin TSSOP (K-8) Pin Description Pin Number 1 2 3 4 5 6 7 8 Pin Name VDDA VEE XTAL_OUT XTAL_IN NC /Q0 Q0 VDD Type PWR PWR O, (SE) I, (SE) − O, (DIF) O, (DIF) PWR LVPECL LVPECL 12pF crystal 12pF crystal Level Pin Function Analog 2.5V or 3.3V Power Supply. No filter resistor needed. Ground. Crystal Reference Output, no load caps needed. Crystal Reference Input, no load caps needed. No Connect Differential Clock Output Differential Clock Output 2.5V or 3.3V Power Supply October 2010 2 M9999-100110-A hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM843251-156 Absolute Maximum Ratings(1) 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 Operating Ratings(2) Supply Voltage (VDD, VDDA) ........................ +2.375 to +3.465 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 VDD VDDA IDDA IEE Parameter Core Supply Voltage Analog Supply Voltage Analog Supply Current Total Supply Current Included in IEE No load Condition Min. 3.135 3.135 Typ. 3.30 3.30 50 88 Max. 3.465 3.465 60 110 Units V V mA mA VDD = VDDA = 2.5V ±5%; TA = –40°C to +85°C, unless noted. Symbol VDD VDDA IDDA IEE Parameter Core Supply Voltage Analog Supply Voltage Analog Supply Current Total Supply Current Included in IEE No load Condition Min. 2.375 2.375 Typ. 2.50 2.50 50 80 Max. 2.625 2.625 60 100 Units V V mA 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 VOH VOL VSWING 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 with a transverse airflow greater than 500 lfpm. See Figure 4 for load test circuit example. Parameter Output High Voltage Output Low Voltage Peak-to-Peak Output Voltage Swing Condition 50Ω to VDD − 2V 50Ω to VDD − 2V Min. VDD – 1.145 VDD – 1.945 0.6 Typ. VDD – 0.97 VDD – 1.77 0.8 Max. VDD – 0.845 VDD – 1.645 1.0 Units V V V 2. 3. 4. October 2010 3 M9999-100110-A hbwhelp@micrel.com or (408) 955-1690 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 FOUT tJITTER t R / tF ODC 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. Parameter Output Frequency RMS Phase Jitter (Output = 156.25 MHz) Output Rise/Fall Time Output Duty Cycle Condition 25MHz Crystal Integration Range: 1.875MHz to 20MHz 20% to 80% Min. Typ. 156.25 110 Max. Units MHz fs 80 48 175 50 350 52 ps % 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 October 2010 4 M9999-100110-A hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM843251-156 Figure 1. Duty Cycle Timing Figure 2. All Outputs Rise/Fall Time Figure 3. RMS Phase Noise/Jitter October 2010 5 M9999-100110-A hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM843251-156 Figure 4. LVPECL Output Load and Test Circuit Figure 5. Crystal Input Interface October 2010 6 M9999-100110-A hbwhelp@micrel.com or (408) 955-1690 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. October 2010 7 M9999-100110-A hbwhelp@micrel.com or (408) 955-1690