19-5214; Rev 0; 4/10 Spread-Spectrum Clock Generators The MAX31C80/MAX31D80 are spread-spectrum clock generators that contain a phase-locked loop (PLL) that generates a 2MHz to 134MHz clock from an input clock or crystal. The PLL can provide a spread-spectrum down-dithered (MAX31D80) or center-dithered (MAX31C80) frequency-modulated clock. The devices also buffer the incoming clock and provide this output on a separate pin. The MAX318C80/MAX31D80 are provided in a 10-pin TDFN package and operate over a full -40NC to +125NC automotive temperature range. Devices can be factory programmed for multiple combinations of input and output frequencies (see the Ordering Information table). A low-cost, low-frequency crystal can be used at the input to generate frequencies up to 134MHz. Typical Application Circuit Features S 2MHz to 134MHz Spread-Spectrum Clock Generator S Input Can Be Either an 8MHz to 34MHz Crystal or 8MHz to 134MHz Clock S Factory-Programmable Output Frequencies in 2MHz to 134MHz Range S Low-Cost Crystal at Low Frequency Used to Generate High Frequencies S On-Board PLL is Capable of Spread-Spectrum Frequency Modulation S Down- or Center-Dither Spread-Spectrum Frequency Modulation S User-Configurable Spread-Spectrum Dither Magnitude S Low Cycle-to-Cycle Jitter S 3.3V Supply Voltage fIN = 27MHz S Temperature Range: -40NC to +125NC S Small Package: 10-Pin TDFN (3mm x 3mm x 0.8mm) fIN = 27MHz X1 X2 MAX31D80 VCC SMSEL1 SMSEL0 GND Applications XOUT CLKOUT 27MHz CLOCK Graphics Cards fCLKOUT = 100MHz 1.5% DOWN DITHERED Set-Top Boxes Automotive Infotainment VCC VCC DECOUPLING CAPACITOR Printers Ordering Information PART MAX31C80T-xxx+ TEMP RANGE -40NC to +125NC DITHER MODE Center PIN-PACKAGE 10 TDFN-EP* MAX31C80T-xxx+T -40NC to +125NC Center 10 TDFN-EP* MAX31D80T-xxx+ -40NC to +125NC Down 10 TDFN-EP* MAX31D80T-xxx+T -40NC to +125NC Down 10 TDFN-EP* xxx = Factory-programmable output frequency and dither rate (see the Selector Guide table). +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad. Selector Guide appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products 1 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. MAX31C80/MAX31D80 General Description MAX31C80/MAX31D80 Spread-Spectrum Clock Generators ABSOLUTE MAXIMUM RATINGS Voltage Range on VCC Relative to GND...............-0.3V to +4.3V Voltage Range on Any Other Pin Relative to GND..................................... -0.3V to (VCC + 0.3V)* Continuous Power Dissipation (TA = +70°C) 10-Pin TDFN (derate 24.4mW/°C above +70°C)......1951.2mW Storage Temperature Range............................. -55NC to +135NC Lead Temperature (soldering, 10s).................................+300NC Soldering Temperature (reflow).......................................+260NC *Not to exceed +4.3V. 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 = -40NC to +125NC.) PARAMETER Supply Voltage SYMBOL CONDITIONS VCC MIN TYP MAX UNITS 3.0 3.3 3.6 V V Input Logic 0 (SMSEL0 and SMSEL1) VIL -0.3 0.25 x VCC Input Logic 1 (SMSEL0 and SMSEL1) VIH 0.75 x VCC VCC + 0.3 V Input Logic Unconnected (SMSEL0 and SMSEL1) VIF 0.4 x VCC 0.55 x VCC V Limits are in case user wants to force voltage instead of unconnecting this pin Input Logic 0 for X1 VIL:X1 -0.3 0.3 x VCC V Input Logic 1 for X1 VIH:X1 0.7 x VCC VCC + 0.3 V 15 pF XOUT Load CLKOUT Load Crystal Frequency Clock Input Frequency CL:XOUT CL:CLKOUT 2MHz P fCLKOUT < 67MHz 15 67MHz P fCLKOUT < 101MHz 10 101MHz P fCLKOUT P 134MHz 7 pF fIN 8 34 MHz fIN 8 134 MHz Crystal ESR XESR Clock Input Duty Cycle fINDC Crystal Parallel Load Capacitance CCL 40 2 _______________________________________________________________________________________ 90 I 60 % 18 pF Spread-Spectrum Clock Generators (3.0V P VCC P 3.6V, TA = -40NC to +125NC, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Current IDD fIN = 27MHz, fCLKOUT = 100MHz, down dithered, CL = 10pF Input Leakage (SMSEL0 and SMSEL1) IIL SMSEL_ = GND or VCC Q15 FA 0.2 V Low-Level Output Voltage (XOUT and CLKOUT) VOL IOL = 10mA High-Level Output Voltage (XOUT and CLKOUT) VOH IOH = -10mA Input Capacitance (X1 and X2) CIN 22 mA VCC 0.2 V 5 pF AC ELECTRICAL CHARACTERISTICS (3.0V P VCC P 3.6V, TA = -40NC to +125NC, unless otherwise noted.) PARAMETER CLKOUT Duty Cycle XOUT Duty Cycle SYMBOL fCLKOUT:DC fXOUT:DC CONDITIONS MIN TYP 40 60 CL:XOUT = 7pF, TA = +25NC, VCC = 3.3V 40 60 Rise Time tR CL:CLKOUT = 7pF 1.6 Fall Time tF CL:CLKOUT = 7pF 1.6 Dither Rate Range fDR Factory programmable Dither Rate Accuracy Peak Cycle-to-Cycle Jitter Power-Up Time tJ tPUP MAX CL:CLKOUT = 7pF UNITS % ns ns 20 40 kHz -4 +4 % CLKOUT = 100MHz, 10,000 cycles, TA = +25NC 75 ps VCC valid to output active, TA = +25NC, VCC = 3.3V 1 ms _______________________________________________________________________________________ 3 MAX31C80/MAX31D80 DC ELECTRICAL CHARACTERISTICS Typical Operating Characteristics (VCC = +3.3V, TA = +25°C, unless otherwise noted.) TA = +125°C TA = +25°C 25 23 21 19 15 10 5 VCC = 3.0V 0 15 3.2 3.4 3.6 -40 -15 SUPPLY VOLTAGE (V) 10 35 60 85 110 fCLKOUT = 100MHz 54 TA = +125°C 52 TA = +25°C 50 60 48 56 46 VCC = 3.6V 50 VCC = 3.3V 48 VCC = 3.0V 42 40 40 3.0 3.2 3.4 3.6 -40 10 60 110 SUPPLY VOLTAGE (V) TEMPERATURE (°C) FREQUENCY SPECTRUM AT 122MHz WITH CENTER SPREAD FREQUENCY SPECTRUM AT 100MHz WITH DOWN DITHER -14.23dB -20 -30 -40 -50 -60 119.2 0 MAX31C80 toc06 fCLKOUT = 122MHz CENTER DITHER = ±1.5% fCLKOUT = 100MHz CENTER DITHER = -3% -10 ATTENUATION (dB) ATTENUATION (dB) 52 44 TA = -40°C 42 -10 54 46 44 0 fCLKOUT = 100MHz 58 DUTY CYCLE (%) DUTY CYCLE (%) 56 80 DUTY CYCLE vs. TEMPERATURE MAX31C80 toc04 58 56 OUTPUT FREQUENCY (MHz) DUTY CYCLE vs. SUPPLY VOLTAGE 60 32 8 TEMPERATURE (°C) MAX31C80 toc05 3.0 VCC = 3.3V 20 VCC = 3.3V 17 15 25 MAX31C80 toc03 27 TA = -40°C 17 VCC = 3.6V MAX31C80 toc07 19 fIN = 27MHz fCLKOUT = 100MHz SUPPLY CURRENT (mA) 23 21 29 SUPPLY CURRENT vs. OUTPUT FREQUENCY MAX31C80 toc02 25 fIN = 27MHz fCLKOUT = 100MHz SUPPLY CURRENT (mA) 27 SUPPLY CURRENT vs. TEMPERATURE MAX31C80 toc01 SUPPLY CURRENT vs. SUPPLY VOLTAGE SUPPLY CURRENT (mA) MAX31C80/MAX31D80 Spread-Spectrum Clock Generators -16.56dB -20 -30 -40 -50 -60 121.2 123.2 FREQUENCY (MHz) 96 98 100 FREQUENCY (MHz) 4 _______________________________________________________________________________________ 104 Spread-Spectrum Clock Generators 8MHz TO 134MHz CLOCK OR 8MHz TO 34MHz CRYSTAL fIN VCC MAX31C80 MAX31D80 VCC X1 X2 PROGRAMMABLE PLL WITH SPREAD SPECTRUM CRYSTAL OSCILLATOR CLKOUT (fCLKOUT = 2MHz TO 134MHz) XOUT (fXOUT = fIN) SMSEL0 GND SPREAD-SPECTRUM MAGNITUDE CONTROL SMSEL1 X2 SMSEL1 VCC GND XOUT Pin Configuration 10 9 8 7 6 TOP VIEW MAX31C80 MAX31D80 4 5 CLKOUT SMSEL0 3 GND 2 VCC 1 X1 + EP TDFN Pin Description PIN 1 2, 9 NAME X1 SMSEL0, SMSEL1 FUNCTION Crystal Drive/Clock Input. A crystal with the proper loading is connected across X1 and X2. Instead of a crystal, a clock can be applied at the X1 input. If no clock or crystal is present, then no clock is output at either XOUT or CLKOUT. Spread-Spectrum Magnitude Select. These are three-state digital inputs to determine the spread-spectrum magnitude. Tables 1 and 2 provide details for configuration of these pins for down and center dither, respectively. PIN NAME 3, 8 VCC Supply Voltage FUNCTION 4, 7 GND Ground 5 CLKOUT Clock Output. Spread-spectrum-capable digital output clock from the PLL. 6 XOUT Crystal Buffered Output. Buffered digital output of the input crystal or clock. 10 X2 Crystal Drive Output. A crystal with the proper loading is connected across X1 and X2. If a clock is applied at the X1 input, then X2 should be left open circuit. — EP Exposed Pad. Connect to GND. _______________________________________________________________________________________ 5 MAX31C80/MAX31D80 Block Diagram MAX31C80/MAX31D80 Spread-Spectrum Clock Generators Detailed Description buffer the incoming clock and provide this output on a separate pin. The MAX31C80/MAX31D80 modulate an input clock to generate a center-dithered or down-dithered spreadspectrum output. An 8MHz to 27MHz crystal or 8MHz to 134MHz oscillator input is applied to the device. An internal PLL dithers the output clock at a user-selectable magnitude to produce a down-dithered or centerdithered output clock. The output clock’s frequency is programmable from 2MHz to 134MHz. The devices also Spread-Spectrum Dither Magnitude The MAX31D80 can generate down-dithered magnitudes up to -3%. The MAX31C80 can generate center-dithered magnitudes up to P 1.5%. The desired magnitude is selected using the input pins SMSEL1 and SMSEL0 as shown in Tables 1 and 2. A power cycle is required after each change of the dither magnitude for the changes to take effect. Table 1. Spread-Spectrum Mode and Magnitude Select (for Down Dither) SPREAD-SPECTRUM MAGNITUDE SELECTED (%) SMSEL1 SMSEL0 0 0 0 Unconnected 0 to -0.25 0 1 0 to -0.375 Unconnected 0 0 to -0.5 Unconnected Unconnected 0 to -0.75 Unconnected 1 0 to -1.0 1 0 0 to -1.5 1 Unconnected 0 to -2.0 1 1 0 to -3.0 SPREAD-SPECTRUM DITHER MODE SELECTED Spread-Spectrum Disabled Down Dither Table 2. Spread-Spectrum Mode and Magnitude Select (for Center Dither) SMSEL1 SMSEL0 SPREAD-SPECTRUM MAGNITUDE SELECTED (%) 0 0 0 Unconnected -0.25 to +0.25 SPREAD-SPECTRUM DITHER MODE SELECTED Spread-Spectrum Disabled 0 1 -0.375 to +0.375 Unconnected 0 -0.5 to +0.5 Unconnected Unconnected -0.75 to +0.75 Unconnected 1 -1.0 to +1.0 1 0 -1.5 to +1.5 1 Unconnected N/A 1 1 N/A Center Dither 6 _______________________________________________________________________________________ Spread-Spectrum Clock Generators FREQUENCY IF SMSEL0 = SMSEL1 = 0 fCLKOUT DITHER AMOUNT (-0.25% TO -3.0%) fCLKOUT - (0.25% TO 3%) 1 DITHER CYCLE RATE TIME Figure 1. Spread-Spectrum Frequency Modulation (Down Dithered) CENTER DITHERED (MAX31C80) FREQUENCY IF SMSEL0 = SMSEL1 = 0 fCLKOUT + (0.25% TO 1.5%) DITHER AMOUNT (±0.25% TO ±1.5%) fIN fCLKOUT - (0.25% TO 1.5%) 1 DITHER CYCLE RATE TIME Figure 2. Spread-Spectrum Frequency Modulation (Center Dithered) _______________________________________________________________________________________ 7 MAX31C80/MAX31D80 DOWN DITHERED (MAX31D80) MAX31C80/MAX31D80 Spread-Spectrum Clock Generators Factory Programmability VCC The MAX31C80/MAX31D80 can provide a variety of frequencies, which are available to users by ordering the device according to specifications listed in the Selector Guide table. VCC VALID Email the factory at [email protected] to obtain custom output frequencies for specific input frequencies not mentioned in the Selector Guide table. tPUP OUTPUT VALID XOUT Applications Information Power-Supply Decoupling To achieve best results, it is highly recommended that a decoupling capacitor be used on the IC power-supply pins. Typical values of decoupling capacitors are 0.01FF and 0.1FF. Use a high-quality, ceramic, surface-mount capacitor and mount it as close as possible to the VCC pins of the IC to minimize lead inductance. OUTPUT VALID CLKOUT Figure 3. Power-Up Timing Selector Guide PART INPUT FREQUENCY (MHz) OUTPUT FREQUENCY (MHz) DITHER RATE (kHz) DITHER TYPE MAX31C80T-UGQ+ 27 100 31.25 Center MAX31C80T-002+ 25 63.05 32.05 Center MAX31D80T-UGQ+ 27 100 31.25 Down MAX31D80T-003+ 12 12 25 Down +Denotes a lead(Pb)-free/RoHS-compliant package. Package Information For the latest package outline information and land patterns, 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 DOCUMENT NO. 10 TDFN-EP T1033+1 21-0137 8 _______________________________________________________________________________________ Spread-Spectrum Clock Generators REVISION NUMBER REVISION DATE 0 4/10 DESCRIPTION Initial release PAGES CHANGED — 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2010 Maxim Integrated Products 9 Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX31C80/MAX31D80 Revision History