19-6068; Rev 1; 10/11 Spread-Spectrum Crystal Multiplier Features The DS1080CL is a low-jitter, crystal-based clock generator with an integrated phase-locked loop (PLL) to generate spread-spectrum clock outputs from 8MHz to 64MHz. The device is pin programmable to select the clock multiplier rate as well as the dither magnitude. The DS1080CL has a spread-spectrum disable mode and a power-down mode to conserve power. ♦ Generates Spread-Spectrum Clocks from 8MHz to 64MHz Applications ♦ Selectable Clock Multiplier Rates of 1x, 2x, and 4x ♦ Center Spread-Spectrum Dithering ♦ Selectable Spread-Spectrum Modulation Magnitudes of ±0.5%, ±1.0%, and ±1.5% ♦ Spread-Spectrum Disable Mode Automotive Copiers ♦ Low Cycle-to-Cycle Jitter Cable Modems Infotainment ♦ Power-Down Mode with High-Impedance Output Cell Phones PCs ♦ Low-Power Consumption Computer Peripherals Printers ♦ 3.0V to 3.6V Single-Supply Operation Pin Configuration ♦ -40°C to +125°C Temperature Operation ♦ Small 8-Pin µSOP Package TOP VIEW Ordering Information + X1 GND 1 2 8 DS1080CL 7 X2 PART VCC CMSEL 3 6 SSO SMSEL 4 5 PDN TEMP RANGE PIN-PACKAGE DS1080CLU+ -40°C to +125°C 8 μSOP DS1080CLU+T -40°C to +125°C 8 μSOP DS1080CLU/V+ -40°C to +125°C 8 μSOP DS1080CLU/V+T -40°C to +125°C 8 μSOP +Denotes a lead-free package. /V denotes an automotive qualified part. T = Tape and reel. Typical Operating Circuit CRYSTAL CL2 CL1 X1 GND CMSEL SMSEL 1 2 8 DS1080CL 7 3 6 4 5 X2 VCC VCC SSO DECOUPLING CAPACITOR PDN fSSO VCC NOTE: IN THE ABOVE CONFIGURATION WITH PDN CONNECTED TO VCC, SMSEL CONNECTED TO GND, AND CMSEL OPEN, THE DEVICE IS IN NORMAL OPERATION WITH 2x CLOCK MULTIPLICATION AND A SPREAD-SPECTRUM MAGNITUDE OF ±0.5%. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 DS1080CL General Description DS1080CL Spread-Spectrum Crystal Multiplier ABSOLUTE MAXIMUM RATINGS Voltage Range on VCC Relative to GND .............-0.5V to +3.63V Voltage Range on Any Pin Relative to GND ...............-0.5V to (VCC + 0.5V), not to exceed +3.63V Continuous Power Dissipation (TA = +75°C) µSOP (derate 4.5mW/°C above +70°C).......................362mW Operating Temperature Range .........................-40°C to +125°C Storage Temperature Range .............................-55°C to +125°C Lead Temperature (soldering, 10s) .................................+300°C Soldering Temperature (reflow) .......................................+260°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS (TA = -40°C to +125°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS (Note 1) MIN TYP MAX UNITS 3.0 3.6 V Supply Voltage VCC Input Logic 1 VIH 0.8 x VCC VCC + 0.3 V Input Logic 0 VIL VGND 0.3 0.2 x VCC V Input Logic Open I IF 0V < VIN < VCC (Note 2) ±1 μA Input Leakage I IL 0V < VIN < VCC (Note 3) ±80 μA 15 pF 16 MHz 90 60 % 18 pF TYP MAX UNITS 7 12 mA SSO Load Crystal or Clock Input Frequency CSSO f IN Crystal ESR XESR Clock Input Duty Cycle FINDC Crystal Parallel Load Capacitance CL 8 40 (Note 4) DC ELECTRICAL CHARACTERISTICS (VCC = +3.0V to +3.6V, TA = -40°C to +125°C, unless otherwise noted.) PARAMETER SYMBOL Supply Current ICC1 Power-Down Current ICCQ CONDITIONS Output Leakage (SSO) I OZ PDN = GND Low-Level Output Voltage (SSO) VOL I OL = 4mA High-Level Output Voltage (SSO) VOH I OH = -4mA Input Capacitance (X1/X2) CIN (Note 5) 2 MIN CSSO = 15pF, f SSO = 8MHz PDN = GND, all input pins open -1 2.4 200 μA +1 μA 0.4 V V 5 _______________________________________________________________________________________ pF Spread-Spectrum Crystal Multiplier DS1080CL AC ELECTRICAL CHARACTERISTICS (VCC = +3.0 to +3.6V, TA = -40°C to +125°C, unless otherwise noted.) PARAMETER SSO Duty Cycle SYMBOL SSODC CONDITIONS Measured at VCC/2 MIN TYP 45 MAX 55 UNITS % Rise Time tR (Note 6) 1.6 ns Fall Time tF (Note 6) 1.6 ns tJ f SSO = 8MHz, TA = -40°C to +85°C, 10,000 cycles (Note 5) 75 ps Peak Cycle-to-Cycle Jitter Power-Up Time t POR PDN pin (Note 7) Power-Down Time t PDN PDN pin (Notes 8, 9) Dither Rate Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8: Note 9: 8MHz 20 16MHz 10 fDITHER 100 ms ns f IN/512 All voltages referenced to ground. Maximum source/sink current applied to input to be considered an open. Applicable to pins CMSEL, SMSEL, and PDN. See information about CL1 and CL2 in the Applications Information section. Not production tested. For 15pF load. Time between PDN deasserted to output active. Time between PDN asserted to output high impedance. Guaranteed by design. _______________________________________________________________________________________ 3 Typical Operating Characteristics (VCC = 3.3V, TA = +25°C, unless otherwise noted.) 6 CMSEL = 1x 4 2 10 CMSEL = 2x 8 6 4 CMSEL = 1x 3.45 3.55 3.65 -40 -15 SUPPLY VOLTAGE (V) CMSEL = 4x 51 50 CMSEL = 2x CMSEL = 1x 48 60 85 8 110 CMSEL = 4x 53 CMSEL = 2x 50 49 64 CMSEL = 1x -15.6dB -40 -50 -60 -70 -80 -90 45 TEMPERATURE (°C) 56 -30 46 110 48 -11dB -14.1dB -20 47 60 40 -10 46 10 32 FREQUENCY SPECTRUM AT 64MHz 52 51 24 0 47 -40 16 FREQUENCY (MHz) 48 45 4 35 fIN = 8MHz 54 DUTY CYCLE (%) 52 49 10 DUTY CYCLE vs. SUPPLY VOLTAGE 55 DS1080CL toc04 fIN = 8MHz 53 4 TEMPERATURE (°C) DUTY CYCLE vs. TEMPERATURE 54 VCC = 3.0V DS1080CL toc06 3.35 ATTENUATION (dB) 3.25 DS1080CL toc05 3.15 6 0 0 3.05 8 fIN = 8MHz 0 2.95 VCC = 3.6V 2 2 fIN = 8MHz 55 10 SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) CMSEL = 2x 8 CMSEL = 4x 12 12 DS1080CL toc02 DS1080CL toc01 CMSEL = 4x 10 SUPPLY CURRENT vs. FREQUENCY SUPPLY CURRENT vs. TEMPRATURE 14 DS1080CL toc03 SUPPLY CURRENT vs. SUPPLY VOLTAGE 12 DUTY CYCLE (%) DS1080CL Spread-Spectrum Crystal Multiplier 3.0 3.1 3.2 3.3 3.4 SUPPLY VOLTAGE (V) 3.5 3.6 61 62 63 64 65 FREQUENCY (MHz) _______________________________________________________________________________________ 66 67 Spread-Spectrum Crystal Multiplier PIN NAME 1 X1 2 GND 3 4 FUNCTION Crystal Drive/Clock Input. A crystal with the proper loading capacitors is connected across X1 and X2. Instead of a crystal, a clock can be applied at the X1 input. Signal Ground CMSEL Clock Multiplier Select. Trilevel digital input. 0 = 1x Open = 2x 1 = 4x SMSEL Spread-Spectrum Magnitude Select. Trilevel digital input. 0 = ±0.5% Open = ±1.0% 1 = ±1.5% 5 PDN Power-Down/Spread-Spectrum Disable. Trilevel digital input. 0 = Power-Down/SSO High Impedance Open = Power-Up/Spread Spectrum Disabled 1 = Power-Up/Spread Spectrum Enabled 6 SSO Spread-Spectrum Clock Multiplier Output. Outputs a 1x, 2x, or 4x spread-spectrum version of the crystal or clock applied at the X1/X2 pins. 7 VCC Supply Voltage 8 X2 Crystal Drive Output. A crystal with the proper loading capacitors is connected across X1 and X2. If a clock is connected to X1, then X2 should be left open circuit. Block Diagram VCC X1 8MHz TO 16MHz X2 CL1 VCC fIN CRYSTAL OSCILLATOR 1x/2x/4x CLOCK MULTIPLYING PLL WITH SPREAD SPECTRUM SSO fSSO fSSO = 8MHz TO 64MHz CL2 PDN CMSEL SMSEL GND CONFIGURATION DECODE AND CONTROL DS1080CL NOTE: SEE INFORMATION ABOUT CL1 AND CL2 IN THE APPLICATIONS INFORMATION SECTION. _______________________________________________________________________________________ 5 DS1080CL Pin Description Detailed Description The DS1080CL is a crystal multiplier with center spread-spectrum capability. An 8MHz to 16MHz crystal is connected to the X1 and X2 pins. Alternately, an 8MHz to 16MHz clock can be applied to X1 in place of the crystal. In such applications, X2 would be left open circuit. Using the CMSEL input, the user selects whether the attached crystal or input clock is multiplied by 1, 2, or 4. The DS1080CL can generate spreadspectrum clocks from 8MHz to 64MHz. The PLL can dither the output clock about its center frequency at a user-selectable magnitude. Using the SMSEL input, the user selects the dither magnitude. The PDN input can be used to place the device into a low-power standby mode where the SSO output is high impedance. If the PDN pin is open, the SSO output is active but the spread-spectrum dithering is disabled. The spread-spectrum dither rate is fixed at fIN/512 to keep the dither rate above the audio frequency range. On power-up, the output clock (SSO) remains high impedance until the PLL reaches a stable frequency (fSSO) and dither (fDITHER). A power cycle is needed for the PLL whenever there is a change in input frequency, CMSEL, or SMSEL. DITHER CYCLE RATE = fDITHER = fIN/512 fSSO DS1080CL Spread-Spectrum Crystal Multiplier +1.5% +1.0% +0.5% fO -0.5% -1.0% -1.5% t Figure 1. Spread-Spectrum Frequency Modulation 6 _______________________________________________________________________________________ Spread-Spectrum Crystal Multiplier Crystal Selection The DS1080CL requires a parallel resonating crystal operating in the fundamental mode, with an ESR of less than 90Ω. The crystal should be placed very close to the device to minimize excessive loading due to parasitic capacitances. Power-Supply Decoupling To achieve best results, it is highly recommended that a decoupling capacitor is used on the IC power-supply pins. Typical values of decoupling capacitors are 0.001μF and 0.1μF. Use a high-quality, ceramic, surface-mount capacitor, and mount it as close as possible to the VCC and GND pins of the IC to minimize lead inductance. Oscillator Input Layout Considerations When driving the DS1080CL using an external oscillator clock, consider the input (X1) to be high impedance. As noted earlier, the crystal should be placed very close to the device to minimize excessive loading due to parasitic capacitances. Care should also be taken to minimize loading on pins that could be open as a programming option (SMSEL and CMSEL). Coupling on inputs due to clocks should be minimized. Crystal Capacitor Selection The load capacitors CL1 and CL2 are selected based on the crystal specifications (from the data sheet of the crystal used). The crystal parallel load capacitance is calculated as follows: CL = CL1 x CL2 + CIN CL1 + CL2 (1) For the DS1080CL use CL1 = CL2 = CLX. In this case, the equation then reduces to: CL = CLX + CIN 2 (2) Package Information For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 8 μSOP U8+1 21-0036 90-0092 where CL1 = CL2 = CLX. Equation 2 is used to calculate the values of CL1 and CL2 based on values of CL and CIN noted in the electrical specifications. _______________________________________________________________________________________ 7 DS1080CL Applications Information DS1080CL Spread-Spectrum Crystal Multiplier Revision History REVISION NUMBER REVISION DATE 0 5/08 1 10/11 DESCRIPTION Initial release PAGES CHANGED — Updated the Ordering Information table and the Absolute Maximum Ratings section; added the land pattern no. to the Package Information table 1, 2, 7 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.