SY89856U 2GHz, Low-Power, 1:6 LVPECL Fanout Buffer with 2:1 Input MUX and Internal Termination General Description The SY89856U is a 2.5V/3.3V precision, high-speed, 1:6 fanout capable of handling clocks up to 2.0GHz. A differential 2:1 MUX input is included for redundant clock switchover applications. The differential input includes Micrel's unique, 3-pin input termination architecture that allows the device to interface to any differential signal (AC- or DC-coupled) as small as 100mV (200mVpp) without any level shifting or termination resistor networks in the signal path. The outputs are LVPECL (100k, temperature compensated), with extremely fast rise/fall times guaranteed to be less than 200ps. The SY89856U operates from a 2.5V 5% supply or a 3.3V 10% supply and is guaranteed over the full industrial temperature range of -40C to +85C. The SY89856U is (R) part of Micrel's high-speed, Precision Edge product line. Datasheets and support documentation are available on Micrel's web site at: www.micrel.com. Features 6 ultra-low skew copies of the selected input 2:1 MUX input included for clock switchover applications Low power: 225mW typical (2.5V) 2.5V to 3.3V supply voltage Unique input isolation design minimizes crosstalk Guaranteed AC performance over temperature and voltage: Clock frequency range: DC to >2.0GHz <400ps IN-to-OUT tpd <200ps tr/tf times <30ps skew (output-to-output) Ultra-low jitter design: 40fs RMS phase jitter 0.7psRMS crosstalk-induced jitter Unique input termination and VT pin accepts DC- and AC-coupled inputs (CML, PECL, LVDS) 100k LVPECL compatible output swing -40C to +85C industrial temperature range Available in 32-pin (5mm x 5mm) QFN package Applications Redundant clock distribution All SONET/SDH clock/data distribution All Fibre Channel distribution All Gigabit Ethernet clock distribution Markets LAN/WAN Enterprise servers ATE Test and measurement United States Patent No. RE44,134 Precision Edge 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 Oct. 1, 2013 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U Ordering Information(1) Part Number SY89856UMG (2) SY89856UMGTR Package Type Operating Range Package Marking Lead Finish QFN-32 Industrial SY89856U with Pb-Free bar-line indicator NiPdAu Pb-Free QFN-32 Industrial SY89856U with Pb-Free bar-line indicator NiPdAu Pb-Free Notes: 1. Contact factory for die availability. Dice are guaranteed at TA = 25C, DC Electricals only. 2. Tape and Reel. Pin Configuration 32-Pin QFN Oct. 1, 2013 2 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U Pin Description Pin Number Pin Name Pin Function 1, 4 5, 8 IN0, /IN0 IN1, /IN1 Differential Input: These input pairs are the differential signal inputs to the device. These inputs accept AC- or DC-coupled signals as small as 100mV (200mVp-p). Each pin of a pair internally terminates to a VT pin through 50. Note that these inputs will default to an indeterminate state if left open. Please refer to the "Input Interface Applications" section for more details. 2, 6 VT0, VT1 Input Termination Center-Tap: Each side of the differential input pair terminates to a VT pin. The VT0 and VTI pins provide a center-tap to a termination network for maximum interface flexibility. See the "Input Interface Applications" section for more details. 31 SEL This single-ended TTL/CMOS-compatible input selects the inputs to the multiplexer. Note that this input is internally connected to a 25k pull-up resistor and will default to logic HIGH state if left open. The MUX select switchover function is asynchronous. 10 NC No connect. 11, 16, 18, 23, 25, 30 VCC 29, 28 27, 26 22, 21 20, 19 15, 14 13, 12 Q0, /Q0, Q1, /Q1, Q2, /Q2, Q3, /Q3, Q4, /Q4, Q5, /Q5 9, 17, 24, 32 GND, Exposed Pad 3, 7 VREF-AC0 VREF-AC1 Positive Power Supply: Bypass with 0.1F//0.01F low ESR capacitors as close to VCC pins as possible. Differential Outputs: These 100k (temperature compensated) LVPECL output pairs are low skew copies of the selected input. Unused output pins may be left floating. Please refer to the "LVPECL Output Interface Applications" section for details. Ground: Ground pins and exposed pad must be connected to the same ground plane. Reference Voltage: This output biases to VCC - 1.2V. It is used for AC-coupling inputs (IN, /IN). Connect VREF_AC directly to the VT pin. Bypass with 0.01F low ESR capacitor to V CC. See the "Input Interface Applications" section. Maximum sink/source current is 1.5mA. Due to the limited drive capability use for input at the same package only. LVPECL Output Interface Applications Oct. 1, 2013 SEL Output 0 IN0 Input Selected 1 IN1 Input Selected 3 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U Functional Block Diagram Oct. 1, 2013 4 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U Absolute Maximum Ratings(3) Operating Ratings(4) Supply Voltage (VCC) .................................... -0.5V to +4.0V Input Voltage (VIN) ............................................ -0.5V to VCC LVPECL Output Current (IOUT) Continuous ............................................................ 50mA Surge .................................................................. 100mA Termination Current Source or sink current on VT............................. 100mA VREF-AC Source or sink current............ .................... 2.0mA Lead Temperature (soldering, 20s) .......................... +260C Storage Temperature (Ts) ........................... -65C to 150C Supply Voltage (VCC) ............................ +2.375V to +2.625V ............................................................... +3.0V to +3.6V Ambient Temperature (TA) .......................... -40C to +85C (5) Package Thermal Resistance QFN (JA) Still-Air ............................................................... 35C/W QFN (JB) Junction-to-Board .............................................. 16C/W DC Electrical Characteristics(6) TA = -40C to +85C, unless otherwise noted. Symbol Parameter VCC Power Supply Voltage Condition Min. Typ. Max. Units 2.375 2.5 2.625 V 3.0 3.3 3.6 V 90 140 mA ICC Power Supply Current No load, max VCC. RIN Input Resistance (IN-to-VT) 45 50 55 RDIFF_IN Differential Input Resistance (IN-to-/IN) 90 100 110 VIH Input High Voltage (IN, /IN) VIH - 1.6 VCC V VIL Input Low Voltage (IN, /IN) 0 VIH-0.1 V VIN Input Voltage Swing (IN, /IN) See Figure 1. 0.1 1.7 V VDIFF_IN Differential Input Voltage Swing |IN-/IN| See Figure 2. 0.2 VT_IN IN-to-VT (IN, /IN) VREF-AC Output Reference Voltage Note 7 V VCC - 1.3 VCC - 1.2 1.28 V VCC - 1.1 V Notes: 3. 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 ratings for extended periods may affect device reliability. 4. The datasheet limits are not guaranteed if the device is operated beyond the operating ratings. 5. Package thermal resistance assumes exposed pad is soldered (or equivalent) to the device's most negative potential on the PCB. JA and JB values are determined for a 4-layer board in still air, unless otherwise stated. 6. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established. 7. VIH (min) not lower than 1.2V. Oct. 1, 2013 5 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U LVPECL DC Electrical Characteristics(6) VCC = 2.5V 5% or 3.3V 10%; TA = -40C to + 85C; RL = 50 to VCC - 2V, unless otherwise noted. Symbol Parameter Condition Min. Typ. Max. Units VOH Output HIGH Voltage VCC - 1.145 VCC - 0.895 V VOL Output LOW Voltage VCC - 1.945 VCC - 1.695 V VOUT Output Voltage Swing See Figure 1. 550 800 mV VDIFF-OUT Differential Output Voltage Swing See Figure 2. 1.1 1.6 V Min. Typ. LVTTL/CMOS DC Electrical Characteristics(6) VCC = 2.5V 5% or 3.3V 10%; TA = -40C to + 85C, unless otherwise noted. Symbol Parameter VIH Input HIGH Voltage VIL Input LOW Voltage IIH Input HIGH Current -125 IIL Input LOW Current -300 Oct. 1, 2013 Condition Max. 2.0 6 Units V 0.8 V 30 A A Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U AC Electrical Characteristics(8) VCC = 2.5V 5% or 3.3V 10%; TA = -40C to + 85C, unless otherwise noted. Symbol Parameter Condition Min. Typ. fMAX Maximum Operating Frequency VOUT 400mV 2.0 3.0 tpd Differential Propagation Delay (IN0 or IN1-to-Q) 200 280 (SEL-to-Q) 140 tpd Tempco Differential Propagation Delay Temperature Coefficient tSKEW Output-to-Output Note 9 Part-to-Part Note 10 RMS Phase Jitter Output = 500MHz Integration Range - 12kHz - 20MHz tJITTER tr, tf Max. Units GHz 400 ps 460 ps o 65 10 Adjacent Channel Crosstalk-Induced Jitter Note 11 Output Rise/Fall Time Full swing, 20% to 80%. fs/ C 30 ps 150 ps 40 75 130 fs 0.7 ps(rms) 200 ps Notes: 8. High-frequency AC-parameters are guaranteed by design and characterization. 9. Output-to-output skew is measured between outputs under identical input conditions. 10. Part-to-part skew is defined for two parts with identical power supply voltages at the same temperature and with no skew of the edges at the respective inputs. 11. Crosstalk is measured at the output while applying two similar differential clock frequencies that are asynchronous with respect to each other at the inputs. Oct. 1, 2013 7 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U Typical Characteristics VCC = 3.3V, GND = 0V, VIN 400mV, tr/tf 300ps, TA = 25C, unless otherwise noted. Output Swing vs. Frequency 900 OUTPUT SWING (mV) 800 700 600 500 400 300 200 100 0 0 1000 2000 3000 4000 5000 6000 FREQUENCY (MHz) Oct. 1, 2013 8 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U Functional Characteristics VCC = 3.3V, GND = 0V, VIN 400mV, tr/tf 300ps, TA = 25C, unless otherwise stated. Oct. 1, 2013 9 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U Singled-Ended and Differential Swings Figure 1. Single-Ended Voltage Swing Figure 2. Differential Voltage Swing Timing Diagrams Oct. 1, 2013 10 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U Input and Output Stages Figure 3. Simplified Differential Figure 4. Simplified LVPECL Output Stage Input Interface Applications Figure 5. DC-Coupled LVPECL Input Interface Figure 6. AC-Coupled LVPECL Input Interface Figure 8. AC-Coupled CML Input Interface Figure 9. LVDS Input Interface Oct. 1, 2013 11 Figure 7. DC-Coupled CML Input Interface Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U lines. There are several techniques for terminating the LVPECL output: parallel termination-Thevenin equivalent, parallel termination (3-resistor), and AC-coupled termination. Unused output pairs may be left floating. However, single-ended outputs must be terminated or balanced. LVPECL Output Interface Applications LVPECL has a high input impedance and a very low output impedance (open emitter), and a small signal swing which results in low EMI. LVPECL is ideal for driving 50 and 100-controlled impedance transmission Figure 10. Parallel Termination-Thevenin Equivalent Note: 12. For 2.5V Systems: R1 = 250, R2 = 62.5. Figure 11. Parallel Termination (3-Resistors) Notes: 13. Power-saving alternative to Thevenin termination. 14. Place termination resistors as close to destination inputs as possible. 15. Rb resistor sets the DC bias voltage, equal to VT. 16. For 2.5V systems, Rb = 19. Related Documentation Part Number Function Datasheet Link SY58035U 4.5GHz, 1:6 LVPECL Fanout Buffer with 2:1 MUX Input and Internal Termination www.micrel.com/_PDF/HBW/sy58035u.pdf HBW Solutions New Products and Applications www.micrel.com/index.php/en/products/clock-timing/clock-datadistribution.html Oct. 1, 2013 12 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89856U Package Information(17) 32-Pin QFN (QFN-32) Note: 17. Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com. 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. (c) 2005 Micrel, Incorporated. Oct. 1, 2013 13 Revision 3.1 hbwhelp@micrel.com or (408) 955-1690