SM802109 ClockWorks™ PCI-e Quad 100MHz Ultra-Low Jitter, HCSL Frequency Synthesizer General Description Features The SM802109 is a member of the ClockWorks™ family of devices from Micrel and provides an extremely low-noise timing solution for PCI-Express clock signals. It is based on 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 four HCSL output clocks at 100MHz. The SM802109 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 four HCSL clock outputs at 100MHz • 2.5V or 3.3V operating range • Typical phase jitter @ 100MHz (1.875MHz to 20MHz): 105fs • Industrial temperature range (–40°C to +85°C) • Green, RoHS, and PFOS compliant • Available in 24-pin 4mm × 4mm QFN package Applications • PCI-Express 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 September 2011 M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 Ordering Information(1) Part Number Marking Shipping Temperature Range Package SM802109UMG 802109 Tube –40°C to +85°C 24-Pin QFN SM802109UMGTR 802109 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 (Top View) Pin Description Pin Number Pin Name 16, 17 /Q0, Q0 Pin Type Pin Level Pin Function 20, 21 /Q1, Q1 O, (DIF) HCSL Differential Clock Outputs from Bank 1 100MHz 23, 24 /Q2, Q2 3, 4 /Q3, Q3 O, (DIF) HCSL Differential Clock Outputs from Bank 2 100MHz 1 VDDO2 PWR Power Supply for Output Bank 2 2 VSSO2 PWR Power Supply Ground for Output Bank 2 PLL Bypass, Selects Output Source 5 PLL_BYPASS I, (SE) LVCMOS 0 = Normal PLL Operation 1 = Output from Input Reference Clock or Crystal 45KΩ pulldown 6 September 2011 XTAL_SEL I, (SE) LVCMOS 2 Selects PLL Input Reference Source 0 = REF_IN, 1 = XTAL, 45KΩ pullup M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 Pin Description (Continued) Pin Number Pin Name 7, 12, 15, 19 TEST 8 VDD 13, 14 Pin Type Pin Level Pin Function Factory Test pins, Do not connect anything to these pins. VSS (Exposed Pad) PWR Core Power Supply PWR Core Power Supply Ground. The exposed pad must be connected to the VSS ground plane. 18 VDDO1 PWR Power Supply for Output Bank 1 22 VSSO1 PWR Power Supply Ground for Output Bank 1 9 REF_IN I, (SE) LVCMOS 10 XTAL_IN I, (SE) Crystal Crystal Reference Input, no load caps needed (see Figure 5). 11 XTAL_OUT O, (SE) Crystal Crystal Reference Output, no load caps needed (see Figure 5). Reference Clock Input Truth Table PLL_BYPASS XTAL_SEL INPUT OUTPUT 0 − − PLL 1 − − XTAL/REF_IN − 0 REF_IN − − 1 XTAL − September 2011 3 M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 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, 20s)............................ 260°C Case Temperature ..................................................... 115°C Storage Temperature (Ts) ......................... −65°C to +150°C Supply Voltage (VDD, VDDO1/2)............... +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, VDDO1/2 Condition Min. Typ. Max. Units 2.5V Operating Voltage 2.375 2.5 2.625 V VDD, VDDO1/2 3.3V Operating Voltage 3.135 3.3 3.465 V IDD REF_IN Supply current VDD + VDDO XTAL_SEL = 0 Outputs 50Ω to VSS 140 175 mA IDD XTAL Supply current VDD + VDDO XTAL_SEL = 1 Outputs 50Ω to VSS 150 185 mA Min Typ. Max. Units HCSL 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 VSS Symbol Parameter Condition VOH Output High Voltage 660 700 850 mV VOL Output Low Voltage -150 0 27 mV VCROSS Crossing Point Voltage 250 350 550 mV 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. September 2011 4 M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 LVCMOS (PLL_BYPASS, XTAL_SEL) 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 Parameter Condition Mode of Oscillation Frequency Equivalent Series Resistance (ESR) Shunt Capacitor, C0 10pF to 12pF Load Min. Max. Units Fundamental, Parallel Resonant 25 Correlation Drive Level September 2011 Typ. 5 1 50 5 MHz Ω pF 10 100 µW M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 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 VSS Symbol Parameter Condition Min. Typ. Max. Units FOUT Output Frequency 100 MHz FREF Reference Input Frequency 25 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 20% – 80% 150 300 450 ps 48 50 52 % Note 6 45 ps 20 ms 100MHz Integration Range (1.875MHz – 20MHz) Integration Range (12kHz – 20MHz) 105 250 fs 25MHz −95 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. 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. September 2011 6 M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 Application Information HCSL Outputs HCSL outputs are to be terminated with 50Ω to VSS. For best performance load all outputs. If you want to ACcouple or change the termination, contact Micrel’s application group: [email protected]. 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 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: [email protected]. September 2011 7 M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 Phase Noise Plots Phase Noise Plot: 100MHz, 1.875MHz − 20MHz 104fS Phase Noise Plot: 100MHz, 12kHz − 20MHz 242fS September 2011 8 M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 Figure 1. Duty Cycle Timing Figure 2. All Outputs Rise/Fall Time Figure 3. RMS Phase/Noise Jitter September 2011 9 M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 Figure 4. HCSL Output Load and Test Circuit Figure 5. Crystal Input Interface September 2011 10 M9999-092911-B [email protected] or (408) 955-1690 Micrel, Inc. SM802109 Package Information 24-Pin Package Type 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. September 2011 11 M9999-092911-B [email protected] or (408) 955-1690