PL607041UMG

PL607041 ClockWorks® PCIe Quad Outputs Ultra-Low Jitter, HCSL Frequency Synthesizer General Description Features ® The PL607041 is a member of the ClockWorks family of devices from Micrel and provides an extremely low-noise Spread-Spectrum clock for PCI Express requirements. The device operates from a 3.3V or 2.5V power supply and synthesizes four HCSL output clocks at 25MHz, 100MHz, 125MHz, and 200MHz. The PL607041 accepts a 25MHz crystal. Datasheets and support documentation are available on Micrel’s web site at: www.micrel.com.  25MHz fundamental crystal or reference input  Generates four HCSL clock outputs at 25MHz, 100MHz, 125MHz, and 200MHz  Spread spectrum for EMI reduction  2.5V or 3.3V operating range  Typical phase jitter @ 100MHz (1.5MHz to 10MHz): 320fs  Compliant with PCI Express Gen1, Gen2, and Gen3  Industrial temperature range (–40°C to +85°C)  RoHS and PFOS compliant  Available in 24-pin 4mm × 4mm QFN package Applications      Servers Storage systems Switches and routers Gigabit Ethernet Set-top boxes/DVRs Block Diagram ClockWorks is a registered trademark of Micrel, Inc. Ripple Blocker is a 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 April 1, 2014 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 Ordering Information(1) Marking Shipping Junction Temperature Range Package PL607041UMG PL607 041 Tube –40° to +85°C 24-Pin QFN PL607041UMG TR PL607 041 Tape and Reel –40° to +85°C 24-Pin QFN Part Number Note: 1. Devices are RoHS and PFOS compliant. Pin Configuration 24-Pin QFN (Top View) Pin Description Pin Number Pin Name Pin Type Pin Level 17, 18 19, 20 /Q0, Q0 /Q1, Q1 O, (DIF) HCSL Differential Clock Outputs pins. 23, 24 1, 2 /Q2, Q2 /Q3, Q3 O, (DIF) HCSL Differential Clock Outputs pins. 9 VDDO2 PWR Power Supply. 16 VDDO1 PWR Power Supply. 7, 15 VDD PWR Core Power Supply. 5, 11, 13 VSS PWR Power Supply Ground. 6, 8 S0, S1 I LVCMOS Frequency Select for 25MHz, 100MHz, 125MHz, and 200MHz. Each pin has a 45kΩ pull-up. 14, 4 SS0, SS1 I LVCMOS Spread Spectrum Select pins. Each pin has a 60kΩ pullup. 22 XIN/FIN I, (SE) Crystal Crystal or Reference Input, no load caps needed (see Figure 5). 21 XOUT O, (SE) Crystal Crystal Output, no load caps needed (see Figure 5). 12 OE I, (SE) LVCMOS 3, 10 TEST I April 1, 2014 Pin Function Output Enable/Disable. Factory test pins. Keep these pins floating. 2 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 EMI Reduction The Spread Spectrum modulation causes the emission of spectral components in the clock signal to be reduced. The spectrum plot on the right shows measurement results with the two spread settings versus no spread. This plot is looking at the 11th harmonic in a 100MHz clock, at 1.1GHz. The scale is normalized to the strength of this spur without spread. The plot shows about 21dB reduction for -0.25% spread magnitude and 24dB for -0.50% spread magnitude. The plot also shows how the frequency spreading is happening downwards. April 1, 2014 3 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 Absolute Maximum Ratings(2) Operating Ratings(3) 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 (VIN) ............................. +2.375V to +3.465V Ambient Temperature (TA) .......................... –40°C to +85°C (4) Junction Thermal Resistance QFN (JA) ........................................................... 50°C/W QFN (JB)........................................................... 30°C/W Electrical Characteristics(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 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 Supply current VDD + VDDO 150 185 mA Min. Typ. Max. Units Outputs 50Ω to VSS HCSL DC Electrical Characteristics(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 VOH Output High Voltage 660 700 850 mV VOL Output Low Voltage –150 0 27 mV VCROSS Crossing Point Voltage 250 350 550 mV Min. Typ. Max. Units LVCMOS (S0, S1) Electrical Characteristics(5) VDD = 3.3V ±5%, or 2.5V ±5%, TA = –40°C to +85°C. Symbol Parameter Condition VIH Input High Voltage 2.0 VDD + 0.3 V VIL Input Low Voltage –0.3 0.8 V IIH Input High Current VDD = VIN = 3.465V 150 µA IIL Input Low Current VDD = 3.465V, VIN = 0V –150 µA Notes: 2. 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. 3. The device is not guaranteed to function outside its operating ratings. 4. Package thermal resistance assumes exposed pad is soldered (or equivalent) to the devices most negative potential on the PCB. 5. The circuit is designed to meet the AC and DC specifications shown in the above table(s) after thermal equilibrium has been established. April 1, 2014 4 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 Crystal Characteristics Parameter Condition Min. Mode of Oscillation 15pF load capacitance Typ. Max. Units Fundamental, Parallel Resonant Frequency 25 MHz Equivalent Series Resistance (ESR) 50 Ω Shunt Capacitor, C0 1 7 pF Correlation Drive Level 10 100 µW AC Electrical Characteristics(6, 7) 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 25 100 125 200 FREF Crystal Input Frequency 25 MHz FIN Reference Input Frequency 25 MHz FIN FIN Signal Amplitude Internally AC-coupled 0.9 TR/TF HCSL Output Rise/Fall Time 20% - 80% 150 ODC Output Duty Cycle 48 TSKEW Output-to-Output Skew TLOCK PLL Lock Time Tjit(Ø) VDD VPP 300 450 ps 50 52 % 45 ps 20 ms Note 7 100MHz Integration Range (1.5MHz – 10MHz) (8) RMS Phase Jitter MHz 320 Cycle-to-Cycle Jitter fs 30 ps, peak Notes: 6. All phase noise measurements were taken with an Agilent 5052B phase noise system. 7. Defined as skew between outputs at the same supply voltage and with equal load conditions; 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. Spread Spectrum Characteristics Parameter Modulation Rate Condition Min. (9) Modulation Magnitude Typ. Max. 31.6 (10) Units kHz Setting is -0.25% -0.073 to -0.265 0 to -0.250 +0.031 to -0.375 % Setting is -0.50% -0.136 to -0.383 0 to -0.500 +0.078 to -0.589 % Notes: 9. The modulation rate is created from the crystal frequency, divided by 792. 10. The typical modulation makes the output frequency sweep between the target frequency (0%) and the down-spread value (-0.25% or -0.5%). There is process variation on the modulation magnitude and the smallest and largest possible modulation magnitude sweep ranges are listed in the table. April 1, 2014 5 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 Truth Tables SS1 S1 S0 OUTPUT 0 0 25MHz 0 1 100MHz 1 0 125MHz 1 1 200MHz (11) SS0 (11) Spread Type Spread 0 0 Spread is OFF No Spread 0 1 Down Spread -0.25% 1 0 Spread is OFF No Spread 1 1 Down Spread -0.50% Note: 11. SS0 is turning ON/OFF the spread spectrum modulation and SS1 is selecting the spread magnitude. Phase Noise Plot Phase Noise Plot: 100MHz, 1.5MHz – 10MHz 320fs April 1, 2014 6 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 Figure 1. Duty Cycle Timing Figure 2. All Outputs Rise/Fall Times Figure 3. RMS Phase/Noise Jitter April 1, 2014 7 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 Figure 4. HCSL Output Load and Test Circuit Figure 5. HCSL Recommended Application Termination (Source Terminated) Figure 6. Crystal Input Interface April 1, 2014 8 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 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 / Family of Precision Synthesizers application note for more details. The impedance value of the Ferrite Bead (FB) needs to be between 240Ω and 600Ω with a saturation current ≥150mA. VDDO1 and VDDO2 pins connect directly to the VDD Plane. All VDD pins on the PL607041 connect to VDD after the power supply filter. Contact Micrel’s TCG applications group at: tcghelp@micrel.com if you need help selecting a suitable crystal for your application. 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: tcghelp@micrel.com (see Figure 5). Power Supply Decoupling Place the smallest value decoupling capacitor (4.7nF above) between the VDD and VSS pins, as close as possible to those pins and at the same side of the PCB as the IC. The shorter the physical path from VDD to capacitor and back from capacitor to VSS, the more effective the decoupling. Use one 4.7nF capacitor for each VDD pin on the PL607041. Power Supply Filtering Recommendations Preferred filter, using Micrel’s MIC94300 or MIC94310 Ripple Blocker™: Alternative, traditional filter, using a ferrite bead: April 1, 2014 9 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 Package Information(12) 24-Pin QFN Note: 12. Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com. April 1, 2014 10 Revision 1.2 tcghelp@micrel.com or (408) 955-1690 Micrel, Inc. PL607041 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. © 2014 Micrel, Incorporated. April 1, 2014 11 Revision 1.2 tcghelp@micrel.com or (408) 955-1690