SY89221U Precision 1:15 LVPECL Fanout Buffer with 2:1 MUX and Four ÷1/÷2/÷4 Clock Divider Output Banks General Description Features The SY89221U is a 2.5/3.3V precision, high-speed, integrated clock divider and LVPECL fanout buffer capable of handling clocks up to 1.5GHz. Optimized for communications applications, the four independently controlled output banks are phasematched and can be configured for pass through ÷1, ÷2 or ÷4 divider ratios. The differential input includes Micrel’s unique, 3-pin input termination architecture that allows the user 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 low-skew, low-jitter outputs are LVPECL compatible with extremely fast rise/fall times that are guaranteed to be less than 220ps. The /MR (master reset) input asynchronously resets the outputs. A four-clock delay after de-asserting /MR allows the counters to synchronize and start the outputs from the same state without any runt pulse. The SY89221U is part of Micrel’s Precision Edge® product family. All support documentation can be found at Micrel's web site at: www.micrel.com. • Four low-skew LVPECL output banks with independently programmable ÷1, ÷2 and ÷4 divider options • Four output banks, 15 total outputs • Guaranteed AC performance over temperature and voltage: – Accepts a clock frequency up to 1.5GHz – <1600ps IN-to-OUT propagation delay – <270ps rise/fall time – <35 ps within-bank skew • Fail Safe Input – Prevents outputs from oscillating • Ultra-low jitter design: – <1psRMS random jitter – <10psPP total jitter (clock) • Patent-pending input termination and VT pin accepts DC- and AC-coupled inputs (CML, PECL, LVDS) • CMOS/TTL-compatible output enable (EN) and divider select control • 2.5V ±5% or 3.3V ±10% power supply • –40°C to +85°C temperature range • Available in 64-pin TQFP Applications • All SONET/SDH applications • All Fibre Channel applications • All Gigabit Ethernet applications Markets • • • • • LAN/WAN routers/switches Enterprise servers Storage ATE Test and measurement 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 August 2007 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Functional Block Diagram August 2007 2 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Ordering Information(1) Part Number Package Type Operating Range Package Marking Lead Finish SY89221UHY T64-1 Industrial SY89221UHY with Pb-Free bar-line indicator Pb-Free Matte-Sn SY89221UHYTR(2) T64-1 Industrial SY89221UHY with Pb-Free bar-line indicator Pb-Free Matte-Sn Notes: 1. Contact factory for die availability. Dice are guaranteed at TA = 25°C, DC Electricals only. 2. Tape and Reel. Pin Configuration 64-Pin EPAD-TQFP (T64-1) August 2007 3 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Pin Description Pin Number Pin Name Pin Function 1, 2 3, 4 15, 16 17, 18 FSELA1, FSELA0 FSELB1, FSELB0 FSELC1, FSELC0 FSELD1, FSELD0 Single-Ended Inputs: These TTL/CMOS inputs select the divide ratio for each of the four banks of outputs. Note that each of these inputs is internally connected to a 25kΩ pull-up resistor and will default to a logic HIGH state if left open. The input-switching threshold is VCC/2. 5, 8, 11, 14 IN0, /IN0 IN1, /IN1 Differential Inputs: These input pairs are the differential signal inputs to the device. They accept AC- or DC-coupled signals as small as 100mV. The input pairs internally terminate to a VT pin through 50Ω. Note that these inputs will default to an indeterminate state if left open. Please refer to the “Input Interface Applications” section for more details. 6, 12 VT0, VT1 Input Termination Center-Tap: Each side of a differential input pair terminates to a VT pin. The VT pin provides a center-tap to a termination network for maximum interface flexibility. See “ Input Interface Applications” section for more details. 7, 13 VREF-AC0, VREF-AC1 Reference Voltage: These outputs bias to VCC–1.2V. They are used for AC-coupling inputs IN and /IN. Connect VREF-AC directly to the corresponding VT pin. Bypass with 0.01µF low ESR capacitor to VCC. Due to limited drive capability, the VREF-AC pin is only intended to drive its respective VT pin. Maximum sink/source current is ±1.5mA. Please refer to the “Input Interface Applications” section for more details. 9 /MR Single-Ended Input: This TTL/CMOS-compatible master reset function asynchronously sets the true outputs LOW, complimentary outputs HIGH, and holds them in that state as long as /MR remains LOW. This input is internally connected to a 25kΩ pull-up resistor and will default to logic HIGH state if left open. The input-switching threshold is VCC/2. 10 CLK_SEL Single-Ended Input: This TTL/CMOS-compatible input selects the inputs to the multiplexer. Note that this input is internally connected to a 25kΩ pull-up resistor and will default to logic HIGH state if left open. The input-switching threshold is VCC/2. 20, 25, 30, 33, 40 41, 48, 50, 55, 62 VCC Positive Power Supply. Bypass with a 0.1µF||0.01µF low ESR capacitor as close to VCC pin as possible. 21, 22 23, 24 26, 27 28, 29 /QC0, QC0 /QC1, QC1 /QC2, QC2 /QC3, QC3 Bank C LVPECL differential output pairs controlled by FSELC0 and FSELC1. Refer to “Function Table” for details. Unused output pairs may be left open. Each output is designed to drive 800mV into 50Ω terminated to VCC – 2V. 31 NC 34, 35, 36, 37 38, 39, 42, 43 44, 45, 46, 47 /QD0, QD0 /QD1, QD1 /QD2, QD2 /QD3, QD3 /QD4, QD4 /QD5, QD5 Bank D LVPECL differential output pairs controlled by FSELD0 and FSELD1. Refer to “Function Table” for details. Unused output pairs may be left open. Each output is designed to drive 800mV into 50Ω terminated to VCC – 2V. 51, 52 53, 54 /QA0, QA0 /QA1, QA1 Bank A LVPECL differential output pairs controlled by FSELA0 and FSELA1. Refer to “Function Table” for details. Unused output pairs may be left open. Each output is designed to drive 800mV into 50Ω terminated to VCC – 2V. 56, 57 58, 59 60, 61 /QB0, QB0 /QB1, QB1 /QB2, QB2 Bank B LVPECL differential output pairs controlled by FSELB0 and FSELB1. Refer to “Function Table” for details. Unused output pairs may be left open. Each output is designed to drive 800mV into 50Ω terminated to VCC – 2V. August 2007 No connect. 4 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Pin Description (continued) Pin Number Pin Name 64 EN 19, 32, 49, 63 GND, Exposed Pad Pin Function Single-Ended Input: This TTL/CMOS input disables and enables the outputs. It is internally connected to a 25kΩ pull-up resistor and will default to logic HIGH state if left open. When disabled, true outputs go LOW and complementary outputs switches to HIGH. The input switching threshold is VCC/2. For the input enable and disable functional description, refer to Figures 2d and 2e. Ground and exposed pad must be connected to the same GND plane on the board. Function Table /MR(1) EN(2, 3) CLK_SEL FSELx0(4) FSELx1(4) Q 1 1 0 0 0 IN0÷1 1 1 1 0 0 IN1÷1 1 1 0 1 0 IN0÷2 1 1 1 1 0 IN1÷2 1 1 0 X 1 IN0÷4 1 1 1 X 1 IN1÷4 1 0 X X X 0 0 X X X X 0 Notes: 1. /MR asynchronously forces Q LOW (/Q HIGH). 2. EN forces Q LOW between 2 and 6 input clock cycles after the falling edge of EN. Refer to “Timing Diagram” section. 3. EN synchronously enables the outputs between two and six input clock cycles after the rising edge of EN. Refer to “Timing Diagram” section. 4. FSEL valid for each of the banks A, B, C, and D. Banks can be programmed independent of each other. August 2007 5 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VCC) ............................... –0.5V to +4.0V Input Voltage (VIN) .......................................–0.5V to VCC Termination Current Source or sink current on VT ........................±100mA LVPECL Output Current (IOUT) Continuous.......................................................50mA Surge .............................................................100mA Input Current Source or sink current on IN, /IN ...................±50mA VREF-AC Current(3) Source or sink current on VREF-AC ....................±2mA Lead Temperature (soldering, 20sec.) .................. 260°C Storage Temperature (Ts)……...………–65°C to +150°C Supply Voltage (VIN).................+2.375V to +2.625V or ............................................... +3.0V to 3.6V Ambient Temperature (TA).................. –40°C to +85°C Package Thermal Resistance(4) TQFP Still-air (θJA) ............................................35°C/W Junction-to-board (ψJB) ..........................20°C/W DC Electrical Characteristics(5) VCC = +2.5V ±5% or 3.3V ±10%, TA = –40°C to +85°C unless otherwise stated. Symbol Parameter VCC Positive Supply Voltage Range ICC Power Supply Current RDIFF_IN Differential Input Resistance (IN-to-/IN) RIN Condition Min Typ Max Units 2.625 3.6 V 140 190 mA 90 100 110 Ω Input Resistance (IN-to-VT, /IN-to-VT) 45 50 55 Ω VIH Input HIGH Voltage (IN, /IN) 1.2 VCC V VIL Input LOW Voltage (IN, /IN) 0 VIH–0.1 V VIN Input Voltage Swing (IN, /IN) See Figure 1a; Note 6 0.1 2.5 V VDIFF_IN Differential Input Voltage Swing |IN – /IN| See Figure 1b 0.2 VIN_FSI Input Voltage Threshold that Triggers FSI VREF-AC Reference Voltage VT_IN Voltage from Input to VT 2.375 3.0 VCC–1.3 V 30 100 mV VCC–1.2 VCC–1.1 V 1.28 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 ratings 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. ψJB and θJA values are determined for a 4-layer board in still-air number, unless otherwise stated. 5. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established. 6. VIN(max) is specified when VT is floating. August 2007 6 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U LVTTL/CMOS DC Electrical Characteristics(7) VCC = +2.5V ±5% or 3.3V ±10%, TA = –40°C to +85°C, unless otherwise stated. Symbol Parameter VIH Input HIGH Voltage Condition Min VIL Input LOW Voltage IIH Input HIGH Current –125 IIL Input LOW Current -300 Typ Max 2 Units V 0.8 V 30 µA µA LVPECL Outputs DC Electrical Characteristics(7) VCC = +2.5V ±5% or 3.3V ±10%, TA = –40°C to +85°C, RL = 50Ω to VCC–2V, unless otherwise stated. Symbol Parameter Condition Min Typ Max Units VOH Output Voltage HIGH (Q, /Q) VOL Output Voltage LOW (Q, /Q) VCC -1.145 VCC - 0.895 V VCC -1.945 VCC -1.695 V VOUT Output Voltage Swing (Q, /Q) See Figure 1a 550 800 mV VDIFF_OUT Differential Output Voltage Swing |Q – /Q| See Figure 1b 1100 1600 mV Note: 7. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established. August 2007 7 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U AC Electrical Characteristics(8) VCC = +2.5V ±5% or 3.3V ±10%, TA = –40°C to +85°C, RL = 50Ω to VCC–2V, unless otherwise stated. Symbol Parameter Condition Min Typ fMAX Maximum Operating Frequency VOUT ≥ 400mV 1.5 2.0 tPD Differential Propagation Delay IN-to-Q 800 1250 1600 ps CLK_SEL-to-Q 700 1000 1400 ps /MR(H-L)-to-Q 700 1000 1400 ps /MR (L-H)-to-IN 300 tRR Reset Recovery Time tPD Tempco Differential Propagation Delay Temperature Coefficient tSKEW Within-Bank Skew Bank-to-Bank Skew tJITTER tr, tf Max GHz ps 225 Within same fanout bank(9, 10) (11) Same divide setting (11) Units fs/°C 10 35 ps 15 40 ps Bank-to-Bank Skew Different divide setting 60 ps Part-to-Part Skew Note 12 25 400 ps Random Jitter (RJ) Note 13 1 psRMS Total Jitter (TJ) Note 14 10 psPP Cycle-to-Cycle Jitter Note 15 1 psRMS Output Rise/Fall Time (20% to 80%) At full output swing 120 270 ps Duty Cycle Divide-by-2 or Divide-by-4 47 53 Divide-by-1, input > 1GHz 45 55 Divide-by-1, input < 1GHz 47 53 180 % Notes: 8. Measured with 100mV input swing. See “Timing Diagrams” section for definition of parameters. High-frequency AC-parameters are guaranteed by design and characterization. 9. Within-bank skew is the difference in propagation delays among the outputs within the same bank. 10. Skews within banks depend on the number of outputs. Within-bank skew decreases if the bank has lesser outputs. 11. Bank-to-bank skew is the difference in propagation delays between outputs from different banks. Bank-to-bank skew is also the phase offset between each bank, after MR is applied. 12. 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. 13. Random jitter is measured with a K28.7 comma detect character pattern. 12 14. Total jitter definition: with an ideal clock input frequency ≤ fMAX, no more than one output edge in 10 output edges will deviate by more than the specified peak-to-peak jitter value. 15. Cycle-to-cycle jitter definition: the variation of periods between adjacent cycles, Tn–Tn–1 where T is the time between rising edges of the output signal. August 2007 8 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Functional Description Master Reset (/MR) /MR is a TTL/CMOS compatible input that resets the output signals. Internal 25kΩ pull-up resistor defaults the input to logic HIGH if left open. A LOW input to /MR asynchronously sets the true outputs LOW and complimentary outputs HIGH. The outputs will remain in this state until /MR is forced HIGH. Input switching threshold is VCC/2. Refer to Figure 2c. Clock Select (CLK_SEL) CLK_SEL is an asynchronous TTL/CMOS compatible input that selects one of the two input signals. Internal 25kΩ pull-up resistor defaults the input to logic HIGH if left open. Delay between the clock selection and multiplexer selecting the correct input signal depends on the divider settings. The delay varies due to the asynchronous nature of the input. Input switching threshold is VCC/2. Refer to Figure 2a. Enable Outputs (EN) EN is a synchronous TTL/CMOS compatible input that enables/disables the outputs based on the input to this pin. Internal 25kΩ pull-up resistor defaults the input to logic HIGH if left open. A logic LOW input causes the true outputs to go LOW and complementary outputs to go HIGH. It takes 2 to 6 input clock cycles before the outputs are enabled/disabled because the signals are going through a series of flip-flops. Input switching threshold is VCC/2. Refer to Figure 2d and 2e. Fail-Safe Input (FSI) The input includes a special failsafe circuit to sense the amplitude of the input signal and to latch the outputs when there is no input signal present, or when the amplitude of the input signal drops sufficiently below 100mVPK (200mVPP), typically 30mVPK. Maximum frequency of the SY89221U is limited by the FSI function. Refer to Figure 2b. Input Clock Failure Case If the input clock fails to a floating, static, or extremely low signal swing, the FSI function will eliminate a metastable condition and guarantee a stable output signal. No ringing and no undetermined state will occur at the output under these conditions. Please note that the FSI function will not prevent duty cycle distortion in case of a slowly deteriorating (but still toggling) input signal. Due to the FSI function, the propagation delay will depend on rise and fall time of the input signal and on its amplitude. Refer to “Typical Operating Characteristics” for detailed information. August 2007 9 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Single-Ended and Differential Swings Figure 1a. Single-Ended Voltage Swing Figure 1b. Differential Voltage Swing Timing Diagrams Figure 2a. Propagation Delay Figure 2b. Fail Safe Feature August 2007 10 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Timing Diagrams Figure 2c. Reset with Output Enabled August 2007 11 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Timing Diagrams Figure 2d. Enable Timing Figure 2e. Disable Timing August 2007 12 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Typical Operating Characteristics VCC = 3.3V, GND = 0V, VIN = 100mV, RL = 50Ω to VCC-2V, TA = 25°C, unless otherwise stated. August 2007 13 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Functional Characteristics VCC = 3.3V, GND = 0V, VIN = 100mV, RL = 50Ω to VCC-2V, TA = 25°C, unless otherwise stated. August 2007 14 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Input and Output Stages Figure 3a. Simplified Differential Input Stage Figure 3b. Simplified Differential Output Stage Input Interface Applications Figure 4a. CML Interface (DC-Coupled) May connect VT to VCC Figure 4b. CML Interface (AC-Coupled) Figure 4d. LVPECL Interface (AC-Coupled) Figure 4e. LVDS Interface August 2007 15 Figure 4c. LVPECL Interface (DC-Coupled) M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U LVPECL Output Interface Applications LVPECL has high input impedance, and very low output impedance (open emitter), and small signal swing which results in low EMI. LVPECL is ideal for driving 50Ω- and 100Ω-controlled impedance transmission lines. There are several techniques for terminating the LVPECL output: Parallel TerminationThevenin 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. Figure 5b. Parallel Termination (3-Resistor) Figure 5a. Parallel Termination-Thevenin Equivalent Related Product and Support Documentation Part Number Function Data Sheet Link SY89218U Precision 1:15 LVDS Fanout Buffer with 2:1 MUX and Four ÷1/÷2/÷4 Clock Divider Output Banks http://www.micrel.com/_PDF/HBW/sy89218u.pdf SY89200U Ultra-Precision 1:8 LVDS Fanout with Three ÷1/÷2/÷4 Clock Divider Output Banks http://www.micrel.com/_PDF/HBW/sy89200u.pdf SY89202U Ultra-Precision 1:8 LVPECL Fanout with Three ÷1/÷2/÷4 Clock Divider Output Banks http://www.micrel.com/_PDF/HBW/sy89202u.pdf HBW Solutions New Products and Applications http://www.micrel.com/page.do?page=/productinfo/as/HBWsolutions.shtml August 2007 16 M9999-082407-C [email protected] or (408) 955-1690 Micrel, Inc. SY89221U Package Information 64-Pin EPAD-TQFP (T64-1) 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 The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. 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. © 2006 Micrel, Incorporated. August 2007 17 M9999-082407-C [email protected] or (408) 955-1690