SM802140 ClockWorksTM 644.53125MHz LVDS Ultra-Low Jitter, Frequency Synthesizer General Description Features The SM802140 is a member of the ClockWorks family of devices from Micrel and provides an extremely low-noise timing solution for clock signals. It is based upon a unique (R) patented RotaryWave architecture that provides very low phase noise. The device operates from a 3.3V or 2.5V power supply and synthesizes four Differential LVDS clocks at 644.53125MHz The SM802140 accepts a 20.141601MHz crystal input. Data sheets and support documentation can be found on Micrel's web site at: www.micrel.com. Generates four LVDS clocks output at 644.53125MHz 2.5V or 3.3V operating range Typical phase jitter @ 644MHz (1.875MHz to 20MHz): 114 fs (typical) at 3.3V Industrial temperature range Green, RoHS, and PFOS compliant Available in 24-pin 4mm x 4mm QFN package Applications 40GbE Serial PMD clock FPGA Transceiver clock ___________________________________________________________________________________________________________ Block Diagram ClockWorks is a trademark of Micrel, Inc RotaryWave is a registered trademark of Micrel, 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 M9999-012111-A November 2011 1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM802140 Ordering Information Marking Shipping Temperature Range Package SM802140UMG Part Number 802140 Tube -40C to +85C 24-Pin QFN SM802140UMGTR 802140 Tape and Reel -40C to +85C 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 O, (DIFF) LVDS 3, 4 /Q3, Q3 16, 17 /Q0, Q0 20, 21 /Q1, Q1 23, 24 /Q2, Q2 1 VDDO2 PWR 2 VSSO2 PWR Pin Function Differential Clock Outputs at 644.53125MHz Power Supply for Outputs Q2 and Q3 Power Supply Ground for Outputs Q2 and Q3 Bypasses the PLL and Switches the REF_IN or XTAL Frequency to all Outputs 5 PLL_BYPASS I, (SE) LVCMOS 1 = Bypass PLL, output is XTAL or REF_IN 0 = PLL Mode, 45K pull-down 6 XTAL_SEL I, (SE) LVCMOS 7, 12, 15, 19 TEST I, (SE) LVCMOS November 2011 2 Selects PLL Reference Input Mode 0 = REF_IN, 1 = XTAL, 45K pull-up Test Pins. Do Not Connect These Pins to Anything hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM802140 Pin Description (Continued) 8 VDD PWR Power Supply 9 REF_IN I, (SE) LVCMOS 10 XIN I, (SE) crystal 11 XOUT O, (SE) crystal 13 VSS I, (SE) This Pin is not a Power Supply Ground, but MUST be Tied to VSS 14 (Exposed Pad) PWR Power Supply Ground. The exposed pad must be connected to the VSS ground plane. 18 VDDO1 PWR Power Supply for Outputs Q0 and Q1 22 VSSO1 PWR Power Supply Ground for Outputs Q0 and Q1 VSS Reference Clock Input Crystal Input, no load caps needed. See Fig. 6. Crystal Output, no load caps needed. See Fig. 6. Truth Table PLL_BYPASS XTAL_SEL INPUT OUTPUT 0 - - PLL 1 - - XTAL/REF_IN - 0 REF_IN - - 1 XTAL - Application Information Crystal Layout Keep the layers under the crystal as open as possible and do not place switching signals or noisy supplies under the crystal. Crystal load capacitance is built inside the die so no external capacitance is needed. See the Selecting a Quartz crystal for the Clockworks Flex I Family of Precision Synthesizers application note for further details. Contact Micrel's HBW applications group if you need assistance on selecting a suitable crystal for your application at hbwhelp@micrel.com November 2011 3 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM802140 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VDD, VDDO1/2) .................................... +4.6V Input Voltage (VIN). ............................ -0.50V to VDD + 0.5V Lead Temperature (soldering, 20sec.) ...................... 260C Case Temperature ................................................... 115C Storage Temperature (Ts) .......................... -65C to +150 Supply Voltage (VDD, VDDO1/2) .............. +2.375V to +3.465V Ambient Temperature (TA)......................... -40C to +85C (3) Junction Thermal Resistance QFN (JA) Still-Air....................................................... 50C/W QFN (JB) Junction-to-Board ...................................... 32C/W DC Electrical Characteristics(4) VDD = VDDO = 3.3V 5% or 2.5V 5% VDD = 3.3V 5%, VDDO1/2 = 3.3V 5% or 2.5V 5% TA = -40C to +85C. Symbol Parameter VDD, VDDO Condition Min. Typ. Max. Units 2.5V Operating Voltage 2.375 2.5 2.625 V VDD, VDDO 3.3V Operating Voltage 3.135 3.3 3.465 V IDD Supply current VDD + VDDO Outputs open - 204 240 mA 644MHz - 4 Diff LVDS outputs LVCMOS INPUT (XTAL_SEL, PLL_Bypass) DC Electrical Characteristics(4) VDD = 3.3V 5%, or 2.5V 5%, TA = -40C to +85C. Symbol Parameter Condition Min. VIH Input High Voltage VIN Input Low Voltage IIH Input High Current VDD = VIN = 3.465V IIL Input Low Current VDD = 3.465V, VIN = 0V Typ. Max. Units 2 VDD + 0.3 V -0.3 0.8 V 150 A -150 A LVDS OUTPUT DC Electrical Characteristics(4) VDD = VDDO1/2 = 3.3V 5% or 2.5V 5% VDD = 3.3V 5%, VDDO1/2 = 3.3V 5% or 2.5V 5% TA = -40C to +85C. RL = 100 across Q and /Q. Symbol Parameter VOD Differential Output Voltage VOD VOD Magnitude Change VOS Offset Voltage VOS VOS Magnitude Change November 2011 Condition Min Typ Max Units Figure 1 275 350 475 mV 40 mV 1.50 V 50 mV 1.15 4 1.25 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM802140 Crystal Characteristics Parameter Condition Mode of Oscillation 10pF Load Min. (6) Typ. Max. Units Fundamental, Parallel Resonant Frequency 20.141601 Equivalent Series Resistance (ESR) Shunt Capacitor, C0 Correlation Drive Level MHz 1 50 5 pF 10 100 uW AC Electrical Characteristics(4, 5, 6) VDD = VDDO1/2 = 3.3V 5% or 2.5V 5% VDD = 3.3V 5%, VDDO1/2 = 3.3V 5% or 2.5V 5% TA = -40C to +85C. RL = 100 across Q and /Q Symbol Parameter Condition Min. Typ. Max. 644.53125 Units FOUT Output Frequency TR/TF LVDS Output Rise/Fall Time ODC Output Duty Cycle TLOCK PLL Lock Time Tjit() RMS Phase Jitter Integration Range (1.875MHz - 20MHz) Integration Range (12kHz - 20MHz) 114 293 fs Spurious Noise Components 20.141MHz reference nd Reference 2 harmonic rd Reference 3 harmonic -82 -78 -85 dBc 20% - 80% MHz 80 175 350 ps 48 50 52 % 20 ms Note: 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(s) after thermal equilibrium has been established. 5. All phase noise measurements were taken with an Agilent 5052B phase noise system. 6. See Application note, "Selecting a Quartz crystal for the Clockworks Flex I Family of Precision Synthesizers" for further details. 7. Measured using 20.141MHz crystal as the input reference source. If using an external reference input, use a low phase noise source. With an external reference, the phase noise will follow the input source phase noise up to about 1MHz. November 2011 5 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM802140 Phase Noise Plots Phase Noise Plot: 644.53125MHz, 12KHz - 20MHz 293 Fs November 2011 6 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM802140 Phase Noise Plot: 644.53125MHz, 1.875MHz - 20MHz 114 Fs Figure 1. Duty Cycle Timing November 2011 Figure 2. All Outputs Rise/Fall Time 7 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM802140 Figure 3. RMS Phase/Noise/Jitter Figure 4. LVDS Output Load and Test Circuit November 2011 8 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM802140 Figure 5. Crystal Input Interface November 2011 9 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SM802140 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. November 2011 10 (c) 2011 Micrel, Incorporated. hbwhelp@micrel.com or (408) 955-1690