PL671-02 PicoEMI T M Spread Spectrum Clock Generator FEATURES PIN CONFIGURATION PDB^, CLK1 1 GND 2 FIN 3 PL671-02 Advanced programmable PLL with Spread Spectrum Reference Clock input o 1MHz to 200MHz Output Frequency o <200MHz Two programmable I/O pins o PDB for Power Down function o CSEL for Configuration Select o CLK1/CLK2 additional clock outputs Programmable Output Drive Low Cycle to Cycle jitter Single 2.5V or 3.3V 10% power supply Available in 6-pin SOT23 or Thin SOT (TSOT) GREEN/RoHS compliant packaging . 6 CLK0 5 CSEL^, CLK2 4 VDD SOT23-6L TSOT-6L Note: ^ Denotes 60k P ull-up resistor DESCRIPTION The PL671-02 is an advanced Spread Spectrum clock generator (SSCG), and a member of PicoPLLTM Programmable Clock family. The PL671-02 offers up to three 200MHz outputs, and allows for pr ogramming the modulation type (Center or Down Spread) as well as 16 modulation magnitudes (0.125% to 2.0% or -0.25% to -4.0%). In addition, the CSEL pin can be used to toggle the device between 2 pre-programmed configurations. The option of being able to turn `ON/OFF' the Spread Spectrum modulation allows for completing a design with PL671 -02 and having the assurance of turning `ON' the EMI modulation, if EMI becomes an issue. The PL671-02's frequency modulation greatly reduces the fundamental and harmonic frequencies' peak magnitude , therefore reducing the system level Electro Magnetic Interference (EMI), by as much as 20dB BLOCK DIAGRAM SST Modulation FREF FIN PDB CLK[0:2] CSEL Programming Logic Modulation Magnitude* * Optional Pre-defined Modulation Magnitude Control Programmable Function R-Counter 9-bits M-Counter 11-bits /8 /8 Phase Detector Charge Pump Loop Filter VCO FVCO = FREF * (M/R) P-Counter 6-bits Odd/Even FOUT = FVCO / P CLK1/PDB CLK0 /1, /2 /1, /2, /4 CLK2/CSEL Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1(408) 944 -0800 * fax +1(408) 474-1000 * www.micrel.com Rev 07/24/09 Page 1 PL671-02 PicoEMI T M Spread Spectrum Clock Generator KEY PROGRAMMING PARAM ETERS CLK[ 0:2 ] Output Frequency SST Modulation Magnitude (Spread Percentage) FOUT = FREF * M / (R * P) where M =11 bit R = 9 bit P = 6 bit CLK0= FREF, FREF/2 or FVCO/P* CLK1= FREF, FREF/2 or FVCO/P* CLK2= FREF, CLK0, CLK0/2 or CLK0/4 16 programmable modulation magnitudes to choose from: Programmable Input/Output Output Drive Strength Programmable I/O's include: Center Spread: 0.125% PDB - input to 2.0% in 0.125% CSEL Configuration steps Selection - input Down Spread: -0.25% to - CLK[0:2] - output 4.0% in 0.25% steps SST On/Off Control. * `P' is a 6-bit Odd/Even divider. Three optional drive strengths to choose from: Low: 4mA Std: 8mA (default) High: 16mA PACKAGE PIN ASSIGNMENT Name (T)SOT23-6L Pin # Type Description This pin can be programmed as PDB (input) or CLK1 (output). Power Down (PDB) input. This pin has an internal 60K pull up resistor and turns off the oscillator and the output when pulled to logic "0". PDB, CLK1 1 B PDB Logic Osc PLL Output 0 Off Off Hi Z (Default) 1 Normal Operation (Default) Clock1 (CLK1) output. This optional clock can be set to F REF , F REF /2 or F OUT (Programmable PLL output). GND 2 P GND connection FIN 3 I Reference input pin VDD 4 P VDD connection CSEL, CLK2 5 I This pin can be programmed as CSEL (input ) or CLK2 (output). CSEL input. Selector pin used to toggle between two pre programmed configurations. CLK2 output. This optional clock can be set to F REF , CLK0, CLK0/2 or CLK0/4. CLK0 6 O Programmable Clock Output Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1(408) 944 -0800 * fax +1(408) 474-1000 * www.micrel.com Rev 07/24/09 Page 2 PL671-02 PicoEMI T M Spread Spectrum Clock Generator FUNCTIONAL DESCRIPTION PL671-02 is a highly featured, very flexible, advanced programmable PLL design for hi gh performance, low-power Spread Spectrum modulation applications. The PL671 -02 accepts a reference clock input of 1MHz to 200MHz and is capable of producing three SST modulated outputs up to 200MHz. This flexible design allows the PL671 -02 to deliver any PLL generated frequency, F REF (Ref Clk) frequency or F REF /2 to CLK0, CLK1 and/or CLK2. Alternate programming using CSEL allows the device to choose from 2 different pre -programmed settings providing a range of spread settings and outputs to choose from. Some of the design features of the PL671 -02 are mentioned below. PLL Programming The PLL in the PL671-02 is fully programmable. The PLL is equipped with a 9-bit input frequency divider (R-Counter), and an 11-bit VCO frequency feedback loop divider (M-Counter). The output of the PLL is transferred to a 6-bit post VCO Odd/Even divider (P Counter). The output frequency is determined by the following formula [F OUT = (F REF * M)/(R*P). Modulation Magnitude and Type The PL671-02 provides the following programmable capabilities for Modulation Type and Modulation Magnitude (Spread Percentage): Modulation Type Modulation Magnitude Programming Steps Center Spread 0.125% thru 2.00% Down Spread -0.25% thru -4.00% 0.125% 0.25% Modulation Rate The PL671-02 modulation rate is defined as F REF (Ref Clk Frequency) divided by 8 times the R-counter, i.e. Modulation Rate = (F REF / 8R). The rate can be changed by choosing alternate R-Counter settings. The output drive level of each output can be independently programmed to Low Drive (4mA), Standard Drive (8mA) or High Drive (16mA). The output frequency can be programmed up to 200MHz at 3.3V (166MHz at 2.5V). Power-Down Control (PDB) When activated (logic `0'), PDB `Disables the PLL, the oscillator circuitry, counters, and all other active circuitry. In Power Down mode the IC consumes <10A of power. The PDB input incorporates a 60k pull up resistor giving a default condition of logic "1". Configuration Select (CSEL) The PL671-02 has the capability to be programmed with 2 distinct configurations and to toggle "On the Fly" between these configurations using the selector pin CSEL. CSEL incorporates a 60k pull up resistor giving a default condition of logic "1". Clock Outputs (CLK[0:2]) CLK0 is the main clock output. The PL671 -02 can also be programmed with additional clock outputs CLK1 and CLK2. The outputs of CLK[0:2] can be configured as described below: CLK0= FREF, FREF/2 or FVCO/P* CLK1= FREF, FREF/2 or FVCO/P* CLK2= FREF, CLK0, CLK0/2 or CLK0/4 Where F REF - Reference (Ref Clk) Frequency FOUT = FREF * M / (R * P) Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1(408) 944 -0800 * fax +1(408) 474-1000 * www.micrel.com Rev 07/24/09 Page 3 PL671-02 PicoEMI T M Spread Spectrum Clock Generator LAYOUT RECOMMENDATIONS The following guidelines are to assist you with a performance optimized PCB design: Signal Integrity and Termination Considerations Decoupling and Power Supply Considerations - Keep traces short! - Place decoupling capacitors as close as possible to the VDD pin(s) to limit noise from the power supply - Trace = Inductor. With a capacitive load this equals ringing! - Long trace = Transmission Line. Without proper termination this will cause reflections (looks like ringing ). - Design long traces (> 1 inch) as "striplines" or "microstrips" with defined impedance. - Match trace at one side to avoid reflections bouncing back and forth. - Multiple VDD pins should be decoupled se parately for best performance. - Addition of a ferrite bead in series with VDD can help prevent noise from other board sources - Value of decoupling capacitor is frequency dependant. Typical values to use are 0.1 F for designs using frequencies < 50MHz and 0.01F for designs using frequencies > 50MHz. Typical CMOS termination Place Series Resistor as close as possible to CMOS output CMOS Output Buffer To CMOS Input ( Typical buffer impedance 20 50 line Series Resistor Use value to match output buffer impedance to 50 trace. Typical value 30 Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1(408) 944 -0800 * fax +1(408) 474-1000 * www.micrel.com Rev 07/24/09 Page 4 PL671-02 PicoEMI T M Spread Spectrum Clock Generator ELECTRICAL SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS PARAMETERS SYMBOL MIN MAX UNITS V DD -0.5 4.6 V Input Voltage Range VI -0.5 V DD+0.5 V Output Voltage Range VO -0.5 V DD+0.5 V 260 C Supply Voltage Range Soldering Temperature (Green package) 10 Data Retention @ 85C Storage Temperature TS Ambient Operating Temperature* Year -65 150 C -40 85 C Exposure of the device under conditions beyond the limits specified by Maximum Ratings for extended periods may cause permanent damage to the device and affect product reliability. These conditions represent a stress rating only, and functional operations of the device at these or any other conditions above the operational limits noted in this specification is not implied. *Operating temperature is guaranteed by design. Parts are tested to commercial grade only. AC SPECIFICATIONS PARAMETERS Input (FIN) Frequency CONDITIONS @ V DD =3.3V @ V DD =2.5V Input (FIN) Signal Amplitude Internally AC coupled (High Frequency) Internally AC coupled (Low Frequency) Input (FIN) Signal Amplitude 3.3V <50MHz, 2.5V <40MHz @ V DD =3.3V Output Frequency @ V DD =2.5V MIN TYP MAX 200 1 166 UNITS MHz 0.9 V DD Vpp 0.1 V DD Vpp 200 166 MHz Settling Time At power-up (after V DD increases over 2.25V) 2 ms Output Enable Time PDB Function; Ta=25 C, 15pF Load 2 ms Output Rise Time Output Fall Time 15pF Load, 10/90% V DD, Standard Drive 2.0 3.0 15pF Load, 10/90% V DD, High Drive 1.2 1.7 15pF Load, 90/10% V DD, Standard Drive 1.7 2.5 15pF Load, 90/10% V DD, High Drive 1.2 1.7 50 55 % 100 ps Duty Cycle At V DD /2 Cycle to Cycle Jitter* T CYC - CYC Over output frequency range @ 3.3V 45 ns ns Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1(408) 944 -0800 * fax +1(408) 474-1000 * www.micrel.com Rev 07/24/09 Page 5 PL671-02 PicoEMI T M Spread Spectrum Clock Generator DC SPECIFICATIONS PARAMETERS Supply Current, Dynamic, with Loaded Outputs SYMBOL I DD CONDITIONS MIN. TYP. At 27MHz, 3.3V, load=15pF, (PDB=1) PDB=0 [with reference input pin (FIN) pulled down] 2.25 MAX. UNITS 15 mA 10 A 3.63 V 100 ms 0.4 V Operating Voltage V DD Power Supply Ramp t PU Output Low Voltage V OL Time for V DD to reach 90% V DD. Power ramp must be monotonic. I OL = +4mA (Std. Drive) Output High Voltage V OH I OH = -4mA (Std. Drive) V DD - 0.4 V Output Current, Low Drive I OSD V OL = 0.4V, V OH = 2.4V 4 mA Output Current, Standard Drive I OSD V OL = 0.4V, V OH = 2.4V 8 mA Output Current, High Drive I OHD V OL = 0.4V, V OH = 2.4V 16 mA PACKAGE DRAWINGS (GREEN PACKAGE COM PLIANT) SOT23-6L Symbol A A1 A2 b c D E H L e Dimension in MM Min. Max. 1.05 1.35 0.05 0.15 1.00 1.20 0.30 0.50 0.08 0.20 2.80 3.00 1.50 1.70 2.60 3.00 0.35 0.55 0.95 BSC Pin1 Dot E H D A2 A A1 C e b L TSOT-6L Symbol A A1 A2 b c D E H L e Dimension in MM Min. Max. 1.00 0.00 0.10 0.84 0.90 0.30 0.50 0.127 w/o plating 2.90 BSC 1.60 BSC 2.80 BSC 0.30 0.50 0.95 TYP Pin1 Dot E H D A2 A A1 C e b L Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1(408) 944 -0800 * fax +1(408) 474-1000 * www.micrel.com Rev 07/24/09 Page 6 PL671-02 PicoEMI T M Spread Spectrum Clock Generator ORDERING INFORM ATION (GREEN PACKAGE COM PLIANT) For part ordering, please contact our Sales Department: 2180 Fortune Drive, San Jose, CA 95131, USA Tel: (408) 944 492-0800 * Fax: (408) 474-1000 PART NUMBER The order number for this device is a combination of the following: Part Number, Package Type and Operating Temperature Range PL671-02-xxx T C-R Shipping Option R = Tape & Reel None = Tube Part Number 3 Digit ID Code* Temperature Range C = Commercial (0C to 70C) Package Type R = TSOT-6L T = SOT23-6L * Micrel will assign a unique 3-digit ID code for each approved programmed part number. Part/Order Number Marking Package Option PL671-02-xxxRC-R F2xxx 6-Pin TSOT (Tape and Reel) PL671-02-xxxTC-R F2xxx 6-Pin SOT23 (Tape and Reel) Micrel Inc., reserves the right to make changes in its products or specifications, or both at any time without notice. The information furnished by Micrel is believed to be accurate and reliable. However, Micrel makes no guarantee or warranty concerning the accuracy of said information and shall not be responsible for any loss or damage of whatever nature resulting from the use of, or reliance upon this product. LIFE SUPPORT POLICY: Micrel's products are not authorized for use as critical components in life support devices or systems without the express written approval of the President of Micrel Inc. Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1(408) 944 -0800 * fax +1(408) 474-1000 * www.micrel.com Rev 07/24/09 Page 7