SM802111 ClockWorks™ GbE Dual 125MHz Ultra-Low Jitter, LVPECL Frequency Synthesizer General Description Features The SM802111 is a member of the ClockWorks™ family of devices from Micrel and provides an extremely low-noise timing solution for Gigabit Ethernet clock signals. It is based upon a unique patented RotaryWave® architecture that provides very-low phase noise. The device operates from a 3.3V or 2.5V power supply and synthesizes two LVPECL output clocks at 125MHz. The SM802111 accepts a 15MHz LVCMOS reference clock. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. • Generates two LVPECL clock outputs at 125MHz • 2.5V or 3.3V operating range • Typical phase jitter @ 125MHz (1.875MHz to 20MHz): 85fs (typical) at 3.3V • Industrial temperature range • Green, RoHS, and PFOS compliant • Available in 24-pin 4mm × 4mm QFN Applications • Gigabit Ethernet ___________________________________________________________________________________________________________ Block Diagram ClockWorks is a trademark of Micrel, Inc. RotaryWave is a registered 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 April 2011 M9999-041111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802111 Ordering Information Part Number Marking Shipping Junction Temperature Range Package SM802111UMG 802111 Tube –40° to +85°C 24-Pin QFN SM802111UMGR 802111 Tape & Reel –40° to +85°C 24-Pin QFN Note: 1. Devices are Green, RoHS, and PFOS compliant. Pin Configuration 24-Pin QFN (Top View) Pin Description Pin Number Pin Name Pin Type Pin Level Pin Function 16, 17 /Q0, Q0 20, 21 /Q1, Q1 O, (DIF) LVPECL Differential Clock Output. 1, 18 VDDO PWR Power Supply for Clock Output. 2, 22 VSSO PWR Power Supply Grounds for Clock Output. 3, 4, 23, 24 NC No Connect,. Do not connect anything to these pins. PLL Bypass, Selects Output Source 5 PLL_BYPASS I, (SE) 0 = Normal PLL Operation LVCMOS 1 = Output from Input Reference Clock 45KΩ pull-down 7, 10, 11, 12, 15, 19 TEST 8 VDD PWR 9 REF_IN I, (SE) 6, 13, 14 VSS PWR April 2011 Factory Test Pins. Do not connect anything to these pins. Core Power Supply. LVCMOS Reference Clock Input. Core Power Supply Ground. 2 M9999-041111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802111 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VDD, VDDO) .........................................+4.6V Input Voltage (VIN) .............................. −0.50V to VDD + 0.5V Lead Temperature (soldering, 20s)............................ 260°C Case Temperature ..................................................... 115°C Storage Temperature (Ts) ......................... −65°C to +150°C Supply Voltage (VDD, VDDO) .................. +2.375V to +3.465V Ambient Temperature (TA) .......................... –40°C to +85°C Junction Thermal Resistance(3) QFN (θJA) Still-Air.........................................................50°C/W QFN (ψJB) Junction-to-Board........................................30°C/W DC Electrical Characteristics(4) VDD = VDDO = 3.3V ±5% or 2.5V ±5% VDD = 3.3V ±5%, VDDO = 3.3V ±5% or 2.5V ±5% TA = –40°C to +85°C Symbol Parameter Condition VDD, VDDO 2.5V Operating Voltage VDD, VDDO 3.3V Operating Voltage IDD Supply Current, VDD + VDDO Min. Typ. Max. Units 2.375 2.5 2.625 V 3.135 3.3 3.465 V 91 115 mA Outputs open LVPECL DC Electrical Characteristics(4) VDD = VDDO 3.3V ±5% or 2.5V ±5% VDD = 3.3V ±5%, VDDO = 3.3V ±5% or 2.5V ±5% TA = –40°C to +85°C; RL = 50Ω to VDDO − 2V Symbol Parameter VOH Condition Min. Typ. Max. Units Output High Voltage VDDO – 1.145 VDDO – 0.97 VDDO – 0.845 V VOL Output Low Voltage VDDO – 1.945 VDDO – 1.77 VDDO – 1.645 V VSWING Output Voltage Swing 0.6 0.8 1.0 V LVCMOS (PLL_BYPASS) DC Electrical Characteristics(4) VDD = 3.3V ±5% or 2.5V ±5%, TA = –40°C to +85°C Symbol Parameter Condition VIH Input High Voltage VIL Input Low Voltage IIH Input High Current VDD = VIN = 3.465V IIL Input Low Current VDD = 3.465V, VIN = 0V Min. Typ. Max. Units 2 VDD + 0.3 V −0.3 0.8 V 150 μA −5 μA 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 AC and DC specifications shown in the above table after thermal equilibrium has been established. April 2011 3 M9999-041111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802111 Ref_IN DC Electrical Characteristics(4) VDD = 3.3V ±5% or 2.5V ±5%, TA = –40°C to +85°C. Symbol Parameter Condition VIH Input High Voltage VIL Input Low Voltage IIN Input Current Min. VDD = 3.465V, VIN = 0V to VDD Typ. Max. Units 1.1 VDD + 0.3 V −0.3 0.6 V −5 5 μA AC Electrical Characteristics(4, 5) VDD = VDDO = 3.3V ±5% or 2.5V ±5% VDD = 3.3V ±5%, VDDO = 3.3V ±5% or 2.5V ±5% TA = −40°C to +85°C; RL = 50Ω to VDDO − 2V Symbol Parameter Condition FOUT Output Frequency 125 MHz FREF Reference Input Frequency 15 MHz TR/TF LVPECL Output Rise/Fall Time ODC Output Duty Cycle TSKEW Output-to-Output Skew TLOCK PLL Lock Time Tjit(∅) RMS Phase Jitter (7) Spurious Noise Components Min. 20% – 80% Typ. Max. Units 80 175 350 ps 48 50 52 % 45 ps 20 ms Note 6 Output = 125MHz Integration Range (1.875MHz – 20MHz) 85 fs 5MHz -73 dBc Notes: 5. All phase-noise measurements were taken with an Agilent 5052B phase-noise system. 6. Defined as skew between outputs at the same supply voltage and with equal load conditions; Measured at the output differential crossing points. 7. Ref_IN driven with a low-noise source ClockWorks SM802001 programmed for a 15MHz CMOS output. Phase noise will track the input phase noise up to about 1MHz offset frequency. April 2011 4 M9999-041111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802111 SM802111 Phase Noise Plot Phase Noise Plot: 125MHz (1.875MHz − 20MHz 75fs) April 2011 5 M9999-041111-A [email protected] or (408) 955-1690 Micrel, Inc. April 2011 SM802111 Figure 1. Duty Cycle Timing Figure 2. All Outputs Rise/Fall Time Figure 3. RMS Phase Noise/Jitter Figure 4. LVPECL Output Load and Test Circuit 6 M9999-041111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802111 Package Information 24-Pin QFN 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. © 2011 Micrel, Incorporated. April 2011 7 M9999-041111-A [email protected] or (408) 955-1690