SY89874U 2.5GHz, Any Differential, In-to-LVPECL, Programmable Clock Divider/Fanout Buffer with Internal Termination General Description This low-skew, low-jitter device is capable of accepting a high-speed (e.g., 622MHz or higher) CML, LVPECL, LVDS or HSTL clock input signal and dividing down the frequency using a programmable divider ratio to create a frequency-locked, lower speed version of the input clock. Available divider ratios are 2, 4, 8 and 16, or straight passthrough. In a typical 622MHz clock system this would provide availability of 311MHz, 155MHz, 77MHz, or 38MHz auxiliary clock components. The differential input buffer has a unique internal termination design that allows access to the termination network through a VT pin. This feature allows the device to easily interface to different logic standards. A VREF-AC reference is included for AC-coupled applications. The /RESET input asynchronously resets the divider. In the pass-through function (divide by 1) the /RESET synchronously enables or disables the outputs on the next falling edge of IN (rising edge of /N). Data sheets and support documentation can be found on Micrel's web site at: www.micrel.com. Precision Edge(R) Features * Integrated programmable clock divider and 1:2 fanout buffer * Guaranteed AC performance over temperature and voltage: - > 2.5GHz fMAX - < 250ps tr/tf - < 15ps within device skew * Low jitter design: - < 10psPP total jitter - < 1psRMS cycle-to-cycle jitter * Unique input termination and VT pin for DC-coupled and AC-coupled Inputs; CML, PECL, LVDS, and HSTL * TTL/CMOS inputs for select and reset * 100k EP-compatible LVPECL outputs * Parallel programming capability * Programmable divider ratios of 1, 2, 4, 8 and 16 * Low-voltage operation 2.5V or 3.3V * Output disable function * -40C to 85C temperature range * Available in 16-pin (3mm x 3mm) QFN package Applications * SONET/SDH line cards * Transponders * High-end multiprocessor sensors 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 April 2012 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U Ordering Information Part Number Package Type Operating Range Package Marking Lead Finish SY89874UMI QFN-16 Industrial 874U Sn-Pb SY89874UMITR(2) QFN-16 Industrial 874U Sn-Pb Note: 1. Contact factory for die availability. Dice are guaranteed at TA = 25C, DC electricals only. 2. Tape and Reel. Pin Configuration Pin Description Pin Number Pin Name 12, 9 IN, /IN 1, 2, 3, 4 Q0, /Q0 Q1, /Q1 16, 15, 5 S0, S1, S2 6 NC 8 /RESET /DISABLE 10 VREF-AC 11 VT 7, 14 13 VCC GND April 2012 Pin Function Differential Input. Internal 50 termination resistors to VT input. Flexible input accepts any differential input. See "Input Interface Applications" section. Differential Buffered LVPECL Outputs. Divided by 1, 2, 4, 8, or 16. See "Truth Table". Unused PECL outputs may be left floating with no impact on jitter performance. Select Pins. See "Truth Table". LVTTL/CMOS logic levels. Internal 25k pull-up resistor. Logic HIGH if left unconnected (divided by 16 mode). Input threshold is VCC/2. No Connect. LVTTL/CMOS Logic Levels. Internal 25k pull-up resistor. Logic HIGH if left unconnected. Apply LOW to reset the divider (divided by 2, 4, 8, or 16 mode). Also acts as a synchronous disable/enable function. The reset and disable function occurs on the next HIGH-to-LOW clock input transition. Input threshold is VCC/2. Reference Voltage. Equal to VCC-1.4V (approximately). Used for AC-coupled applications only. Decouple the VREF-AC pin with a 0.01F capacitor. See "Input Interface Applications" section. Termination Center Tap. For CML or LVDS inputs, leave this floating. Otherwise, see Figures 2a to 2f within the "Input Interface Applications" section. Positive Power Supply. Bypass with .01F /0.01F low-ESR capacitor. Ground. 2 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U Functional Block Diagram Typical Performance Circuit Name April 2012 3 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VCC).................................... -0.5V to +4.0V Input Voltage (VIN). ................................. -0.5V to VCC+0.3V ECL Output Current (IOUT) Continuous............................................................50mA Surge ..................................................................100mA Input Current IN, /IN (IIN) ...........................................50mA VT Current (IVT) ........................................................100mA VREF-AC Sink/Source Current (IVREF-AC), Note 3 ............2mA Lead Temperature (soldering, 20s)............................ 260C Storage Temperature (TS).........................-65C to +150C Supply Voltage (VCC)................. +3.3V 10% or +2.5V 5% Ambient Temperature (TA) .......................... -40C to +85C Package Thermal Resistance QFN (JA) Still-Air.........................................................60C/W 500lfpm .......................................................54C/W QFN (JB), Note 4 Junction-to-Board........................................32C/W DC Electrical Characteristics(5, 6) TA = -40C to +85C; unless otherwise noted. Symbol Parameter VCC Power Supply ICC Power Supply Current Condition Min. 2.375 Max. Units 3.63 V 50 75 mA 90 100 110 No load, maximum VCC Differential Input Resistance RIN Typ. (IN-to-/IN) VIH Input High Voltage (IN, /IN) Note 5 0.1 - VCC + 0.3 V VIL Input Low Voltage (IN, /IN) Note 5 -0.3 - VIH - 0.1 V VIN Input Voltage Swing Notes 5, 6 0.1 - VCC V VDIFF_IN Differential Input Voltage Swing Notes 5, 6, 7 0.2 - IIN Input Current (IN, /IN) Note 5 - - 45 mA VREF-AC Reference Voltage Note 8 VCC - 1.525 VCC - 1.425 VCC - 1.325 V 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. Due to the limited drive capability use for input of the same package only. 4. Junction-to-board resistance assumes exposed pad is soldered (or equivalent) to the device's most negative potential on the PCB. 5. The circuit is designed to meet the DC specifications shown in the DC Electrical Characteristics table after thermal equilibrium has been established. 6. Specification for packaged product only. 7. Due to the internal termination (see Input Buffer Structure), the input current depends on the applied voltages at IN, /IN, and VT inputs. Do not apply a combination of voltages that causes the input current to exceed the maximum limit. Performance might be impacted if the differential inputs are driven single-ended. 8. See Timing Diagram for VT definition. VIN (maximum) is specified when VT is floating. 9. See Typical Operating Characteristics section for VDIFF definition. 10. Operating using VIN is limited to AC-coupled PECL or CML applications only. Connect directly to the VT pin. April 2012 4 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U LVPECL (100KEP) DC Electrical Characteristics(1, 2) VCC = 3.3V 10% or 2.5V 5%; TA = -40C to +85C, RL = 50 to VCC - 2V, unless otherwise stated. Symbol Parameter VOH VOL Condition Min. Typ. Max. Units Output HIGH Voltage VCC - 1.145 VCC - 1.020 VCC - 0.895 V Output LOW Voltage VCC - 1.945 VCC - 1.820 VCC - 1.695 V VOUT Output Voltage Swing 550 800 1050 mV VDIFF_OUT Differential Output Voltage Swing 1.10 1.60 2.10 V Min. Typ. Max. Units LVTTL/CMOS DC Electrical Characteristics(2, 3) VCC = 3.3V 10% or 2.5V 5%; TA = -40C to +85C, unless otherwise stated. Symbol Parameter VIH Input HIGH Voltage VIL Input LOW Voltage IIH Input HIGH Current IIL Input LOW Current Condition 2.0 V 0.8 V 20 A -300 A -125 AC Electrical Characteristics(2, 4) VCC = 3.3V 10% or 2.5V 5%; TA = -40C to +85C, unless otherwise stated. Symbol Parameter Condition Min. Typ. Max. Units fMAX Maximum Output Toggle Frequency Output Swing 400mV 2.5 GHz Maximum Input Frequency Divide by 2, 4, 8, 16 3.2 GHz tPD Differential Propagation Delay Input Swing < 400mV 540 650 790 IN to Q Input Swing 400mV 480 600 730 tSKEW Within-Device Skew (differential) Note 5 7 15 ps ps Q0 - Q1 Part-to-Part Skew (differential) Note 5 tRR Reset Recovery Time Note 6 tJITTER Cycle-to-Cycle Jitter Note 7 1 psRMS Total Jitter Note 8 10 psPP 250 ps tr, tf 250 600 Rise/Fall Time (20% to 80%) 70 ps 150 Notes: 1. The circuit is designed to meet the DC specifications shown in the LVPECL (100KEP) Electrical Characteristics table after thermal equilibrium has been established. 2. Specification for packaged product only. 3. The circuit is designed to meet the DC specifications shown in the LVTTL/CMOS Electrical Characteristics table after thermal equilibrium has been established. 4. Measured with 400mV signal, 50% duty cycle, all outputs loaded with 50 to VCC - 2V, unless otherwise stated. 5. Skew is measured between outputs under identical transitions. 6. See Timing Diagram section. 7. Cycle-to-cycle Jitter Definition: The variation in period between adjacent cycles over a random sample of adjacent cycle pairs. TJITTER_CC = Tn - Tn+1, where T is the time between rising edges of the output signal. 8. Total Jitter Definition: With an ideal clock input, of frequency fMAX (device), no more than one output edge in 10 output edges will deviate by more than the specified peak-to-peak jitter value. April 2012 12 5 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U Timing Diagram April 2012 6 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U Typical Characteristics VCC = 3.3V, VIN = 400mV, TA = +25C, unless otherwise stated. April 2012 7 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U Definition of Single-Ended and Differential Swing Figure 1a. Single-Ended Swing(1) Figure 1b. Differential Swing(2) Notes: 1. Single-ended swing is the amplitude of the signal when driven differentially. 2. Differential swing is defined as IN - /IN (or Q - /Q). Input Buffer Structure Figure 1a. Single-Ended Swing(1) April 2012 Figure 1b. Differential Swing(2) 8 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U Input Interface Applications Figure 3a. DC-Coupled CML Input Interface Figure 3b. AC-Coupled CML Input Interface Figure 3c. DC-Coupled PECL Input Interface Figure 3d. AC-Coupled PECL Input Interface Figure 3e. LVDS Input Interface Figure 3f. HSTL Input Interface Related Product and Support Documentation Part Number Function Data Sheet Link SY89871U 2.5GHz Any Differential In-to-LVPECL Programmable Clock Divider/Fanout Buffer with Internal Termination www.micrel.com/product-info/products/sy89871u.shtml QFN Application Note www.amkor.com/products/notes_papers/mlf_appnote_0902.pdf New Products and Applications www.micrel.com/product-info/products/solutions.shtml HBW Solutions April 2012 9 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U LVPECL Output Termination Recommendations Figure 4a. Parallel Termination-Thevenin Equivalent Note: For +2.5V Systems: R1 = 250, R2 = 62.5. Figure 4b. Three-Resistor "Y-Termination" Notes: Power-saving alternative to Thevenin termination. Place termination resistors as close to destination inputs as possible. Rb resistor sets the DC bias voltage, equal to Vt. For +3.3V systems Rb = 46 to 50. For +2.5V systems, Rb = 39. C1 is an optional bypass capacitor intended to compensate for any tr/tf mismatches. Figure 4c. Terminating Unused I/O Notes: Unused output (/Q) must be terminated to balance the output. For +2.5V Systems: R1 = 250, R2 = 62.5, R3 = 1.25k, R4 = 1.2k. April 2012 10 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690 Micrel, Inc. SY89874U Package Information PCB Thermal Consideration for 16-Pin QFN Package (Always solder, or equivalent, the exposed pad to the PCB) Notes: Package meets Level 2 moisture sensitivity classification, and is shipped in dry-pack. Exposed pads must be soldered to a ground for proper thermal management. 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. April 2012 11 M9999-043012-G hbwhelp@micrel.com or (408) 955-1690