SM802105 ClockWorks™ 10GbE (156.25MHz, 312.5MHz), Ultra-Low Jitter, LVPECL Frequency Synthesizer General Description Features The SM802105 is a member of the ClockWorks™ family of devices from Micrel and provides an extremely low-noise timing solution for 10GbE 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 LVPECL output clocks at 156.25MHz or 312.5MHz. There are normally two clock outputs but one output can be achieved by powering down the second output with the OE pin. The SM802105 accepts a 25MHz crystal or LVCMOS reference clock. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. • Generates one or two LVPECL clock outputs at 156.25MHz or 312.5MHz • 2.5V or 3.3V operating range • Typical phase jitter @ 156.25MHz (1.875MHz to 20MHz): 110fs • Industrial temperature range • Green, RoHS, and PFOS compliant • Available in 24-pin 4mm × 4mm QFN package Applications • 10Gigabit 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 M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 Ordering Information Part Number Marking Shipping Junction Temperature Range(1) Package SM802105UMG 802105 Tube –40°C to +85°C 24-Pin QFN SM802105UMGR 802105 Tape and Reel –40°C to +85°C 24-Pin QFN Note: 1. Devices are Green, RoHS, and PFOS compliant. Pin Configuration 24-Pin QFN (code) (Top View) Pin Description Pin Number Pin Name Pin Type Pin Level Pin Function 19, 20 /Q1, Q1 O, (DIF) LVPECL 22, 23 /Q2, Q2 O, (DIF) LVPECL 24 VDDO2 PWR Power Supply for Output Bank 2 2 VSSO2 PWR Power Supply Ground for Output Bank 2 Differential Clock Output from Bank 1 156.25MHz or 312.5MHz Differential Clock Output from Bank 2 156.25MHz or 312.5MHz PLL Bypass, Selects Output Source 3 PLL_BYPASS I, (SE) 0 = Normal PLL Operation LVCMOS 1 = Output from Input Reference Clock or Crystal 45KΩ pull-down 4 April 2011 XTAL_SEL I, (SE) Selects PLL Input Reference Source LVCMOS 0 = REF_IN, 1 = XTAL, 45KΩ pull-up 2 M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 Pin Description (Continued) Pin Number Pin Name 5, 11, 16, 18 TEST 1 VDD Pin Type Pin Level Pin Function Factory Test pins, Do not connect anything to these pins. PWR Core Power Supply 13, 14, 15 VSS PWR Core Power Supply Ground 17 VDDO1 PWR Power Supply for Output Bank 1 21 VSSO1 PWR Power Supply Ground for Output Bank 1 8 REF_IN I, (SE) LVCMOS 9 XTAL_IN I, (SE) 12pF crystal 10 XTAL_OUT O, (SE) 12pF crystal 6 FSEL I, (SE) LVCMOS 7 OE1 I, (SE) LVCMOS 12 OE2 I, (SE) LVCMOS Reference Clock Input Crystal Reference Input, no load caps needed. See Fig. 5. Crystal Reference Output, no load caps needed. See Fig. 5. Frequency Select, 1 = 156.25MHz, 0 = 312.5MHz, 45KΩ pull-up Output Enable, Q1 disables to tri-state, 0 = Disabled, 1 = Enabled, 45KΩ pull-up Output Enable, Q2 disables to tri-state, 0 = Disabled, 1 = Enabled, 45KΩ pull-up Application Information Input Reference When operating with a crystal input reference, do not apply a switching signal to REF_IN. Crystal Layout Keep the layers under the crystal as open as possible. Do not place switching signals or noisy supplies under the crystal. Truth Tables PLL_BYPASS XTAL_SEL INPUT 0 − − PLL 1 − − XTAL/REF_IN − 0 REF_IN − − 1 XTAL − FSEL Output Frequency (MHz) 0 312.5 1 156.25 April 2011 OUTPUT 3 M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VDD, VDDOx) ........................................+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, VDDOx)................. +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 = VDDO1/2 = 3.3V ±5% or 2.5V ±5% VDD = 3.3V ±5%, VDDO1/2 = 3.3V ±5% or 2.5V ±5% TA = −40°C to +85°C. Symbol Parameter VDD, VDDOx Min. Typ. Max. Units 2.5V Operating Voltage 2.375 2.5 2.625 V VDD, VDDOx 3.3V Operating Voltage 3.135 3.3 3.465 V 156.25MHz - 1 output 97 125 IDD REF_IN Supply current VDD + VDDO XTAL_SEL = 0 Outputs open 156.25MHz - 2 outputs 114 148 312.5MHz - 1 output 109 140 312.5MHz - 2 outputs 131 170 156.25MHz - 1 output 87 113 156.25MHz - 2 outputs 104 135 312.5MHz - 1 output 99 128 312.5MHz - 2 outputs 121 158 IDD XTAL Condition Supply current VDD + VDDO XTAL_SEL = 1 Outputs open mA mA LVPECL 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 = −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 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(s) after thermal equilibrium has been established. April 2011 4 M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 LVCMOS (PLL_BYPASS, XTAL_SEL, OE1/2, FSEL) 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 −150 μA REF_IN DC Electrical Characteristics(4) VDD = 3.3V ±5%, or 2.5V ±5%, TA = −40°C to +85°C. Symbol Parameter VIH Input High Voltage VIL Input Low Voltage IIN Input Current Condition Min. XTAL_SEL = VIL, VIN = 0V to VDD Max. Units 1.1 VDD + 0.3 V −0.3 0.6 V −5 5 μA XTAL_SEL = VIH, VIN = VDD Typ. 20 µA Crystal Characteristics NDK NX2520SA Parameter Condition Mode of Oscillation Frequency Equivalent Series Resistance (ESR) Shunt Capacitor, C0 Correlation Drive Level 12pF Load April 2011 Min. Typ. Max. Units Fundamental, Parallel Resonant 25 3 100 5 50 7 300 MHz Ω pF uW M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 AC Electrical Characteristics(4, 5) VDD = VDDO1/2 = 3.3V ±5% or 2.5V ±5% VDD = 3.3V ±5%, VDDO1/2 = 3.3V ±5% or 2.5V ±5% TA = −40°C to +85°C. RL = 50Ω to VDDO − 2V Symbol Parameter Condition Min. Typ. Max. Units FOUT1 Output Frequency 1 FSEL=1 156.25 MHz FOUT2 Output Frequency 2 FSEL=0 312.5 MHz Ppm Output ppm Variation Crystal reference. Note 6 FREF Reference Input Frequency TR/TF LVPECL Output Rise/Fall Time ODC Output Duty Cycle TSKEW Output-to-Output Skew TLOCK PLL Lock Time RMS Phase Jitter 50 25 20% – 80% 175 350 48 50 52 % 45 ps 20 ms ps 110 250 (8) Spurious Noise Components ppm MHz 80 Within bank. Note 7 156.25MHz Integration Range (1.875MHz – 20MHz) Integration Range (12kHz – 20MHz) Tjit(∅) −50 fs 312.5MHz Integration Range (1.875MHz – 20MHz) Integration Range (12kHz – 20MHz) 110 250 6.25MHz using 156.25MHz 12.5MHz using 312.5MHz -80 -85 dBc Notes: 5. All phase noise measurements were taken with an Agilent 5052B phase noise system. 6. Crystal tolerance at room less than ± 15ppm, over temp less than ±20ppm. 7. Defined as skew between outputs at the same supply voltage and with equal load conditions and same frequency; Measured at the output differential crossing points. 8. Measured using 25MHz 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. April 2011 6 M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 Phase Noise Plots Phase Noise Plot: 156.25MHz, 1.875MHz − 20MHz 108fS Phase Noise Plot: 156.25MHz, 12kHz − 20MHz 244fS April 2011 7 M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 Phase Noise Plots (Continued) Phase Noise Plot: 312.5MHz, 1.875MHz − 20MHz 113fS Phase Noise Plot: 312.5MHz, 12kHz − 20MHz 248fS April 2011 8 M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 Figure 1. Duty Cycle Timing Figure 2. All outputs Rise/Fall Time Figure 3. RMS Phase/Noise Jitter April 2011 9 M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 Figure 4. LVPECL Output Load and Test Circuit Figure 5. Crystal Input Interface April 2011 10 M9999-042111-A [email protected] or (408) 955-1690 Micrel, Inc. SM802105 Package Information (4mm x 4mm) 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 11 M9999-042111-A [email protected] or (408) 955-1690