(R) Final Specification P2781/82/84 Alliance Semiconductor General Purpose EMI Reduction IC FEATURES * Provides up to 15 dB of EMI suppression * FCC approved method of EMI attenuation * Generates a 1X, 2X, and 4X low EMI spread spectrum clock of the input frequency * * Ultra low cycle-to-cycle jitter * Zero-cycle slip * 3.3V operating voltage range Input frequency range from 3 to 78 MHz * 10 mA output drives * External loop filter for spread % adjustment * TTL or CMOS compatible outputs * Spreading ranges from +/-0.25% to +/-5.0% * Ultra-low power CMOS design * Available in 8 pin SOIC and TSSOP PRODUCT DESCRIPTION APPLICATIONS The P278xx is a versatile spread spectrum frequency modulator designed specifically for digital camera and other digital video and imaging applications. The P278xx reduces electromagnetic interference (EMI) at the clock source, which provides system wide reduction of EMI of all clock dependent signals. The P278xx allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. The P278xx uses the most efficient and optimized modulation profile approved by the FCC. The P278xx modulates the output of a single PLL in order to "spread" the bandwidth of a synthesized clock and, more importantly, decreases the peak amplitudes of its harmonics. This results in significantly lower system EMI compared to the typical narrow band signal produced by oscillators and most frequency generators. Lowering EMI by increasing a signal's bandwidth is called "spread spectrum clock generation". The P278xx is targeted towards MFP, xDSL, fax modem, set-top box, USB controller, DSC, and embedded systems. Figure 1 - Pin Diagram X IN 1 8 XOUT 2 7 FS0 3 6 ModOut 5 VSS FS1 LF 4 P278XA-08S P278XA-08T VDD Standard pin configuration offered in both 8 SOIC and TSSOP packages FS0 1 8 ModOut VDD 2 7 VSS X IN 3 6 LF 5 FS1 XOUT 4 P278XB-08T Alternative pin configuration available only for 8 TSSOP package Oct, 2002 Revision F PulseCore - A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 * Santa Clara * CA * 95054 Tel (408) 748-6988 * Fax (408) 748-0009 http://www.pulsecore.com 1 of 1 (R) Final Specification P2781/82/84 Alliance Semiconductor Figure 2 - P278XX Block Diagram FS0 FS1 VDD LF PLL Modulation XIN Crystal Oscillator Frequency Divider XOUT Feedback Divider Phase Detector VCO Output Divider ModOUT P278XX Block Diagram VSS PIN DESCRIPTION (P278XA) PIN # 1 2 3 Name XIN/CLKIN XOUT FS1 Type I I I 4 LF I 5 6 7 VSS ModOUT FS0 I O I 8 VDD P Description Connect to crystal or clock input. Crystal output Digital logic input used to select input frequency range (see Table 1). This pin has an internal pull-up resistor. External Loop Filter for the PLL. By changing the value of the CRC circuit, the % spread can be adjusted accordingly. See Table 2 for detail value. Ground Connection. Connect to system ground. Spread Spectrum Clock Output. Digital logic input used to select input frequency range (see Table 1). This pin has an internal pull-up resistor. Connect to +3.3V Table 1 - Input Frequency Selection Oct, 2002 Revision F FS1 FS0 0 0 1 1 0 1 0 1 Input (MHz) 3 to 9 10 to 19 20 to 38 39 to 78 Output Frequency Scaling (MHz) P2781X P2782X P2784X 3 to 9 6 to 18 12 to 36 10 to 19 20 to 38 40 to 76 20 to 38 40 to 76 80 to 152 39 to 78 78 to 156 to 312 156 Modulation Rate (KHz) Fin / 128 Fin / 256 Fin / 512 Fin / 1024 PulseCore - A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 * Santa Clara * CA * 95054 Tel (408) 748-6988 * Fax (408) 748-0009 http://www.pulsecore.com 2 of 2 (R) Final Specification P2781/82/84 Alliance Semiconductor Table 2 - Loop Filter Selection Table VDD 3.3V R1 PIN 4 LF C2 C1 NOTE: The BW % value is representative of typical conditions. BW=+/-0.50% INPUT (MHz) 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21-22 23-24 25-26 27-28 29-30 31-32 33-34 35-36 37-38 39-42 43-46 47-50 51-54 55-58 59-62 63-66 67-70 71-74 75-78 FS1 FS0 C1 (pF) C2 (pF) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 330,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 R1 (ohms) 220 270 390 510 620 820 1,000 330 390 510 560 620 750 820 910 1,000 1,200 330 390 510 560 620 750 820 910 1,000 1,200 330 390 510 560 620 750 820 910 1,000 1,200 BW=+/-0.75% C1 (pF) C2 (pF) 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 330,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 BW=+/-1.00% R1 (ohms) 300 390 560 750 1,000 1,200 1,500 510 560 750 820 1,000 1,100 1,200 1,300 1,500 1,600 560 620 750 820 1,000 1,100 1,200 1,300 1,500 1,600 560 620 750 820 1,000 1,100 1,200 1,300 1,600 1,800 C1 (pF) C2 (pF) 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 R1 (ohms) 100,000 390 100,000 560 100,000 750 10,000 1,000 5,600 1,200 12,000 2,200 5,600 2,200 100,000 750 100,000 866(1%) 10,000 1,000 12,000 1,200 5,600 1,200 3,900 1,200 12,000 2,200 10,000 2,200 5,600 2,200 3,300 2,200 100,000 750 100,000 866(1%) 10,000 1,000 12,000 1,200 6,800 1,200 3,900 1,200 12,000 2,200 10,000 2,200 5,600 2,200 3,300 2,200 100,000 750 100,000 866(1%) 10,000 1,000 12,000 1,200 6,800 1,200 3,900 1,200 12,000 2,200 8,200 2,200 5,600 2,200 3,300 2,200 BW=+/-1.25% C1 (pF) C2 (pF) 560 560 560 680 330 680 270 560 560 680 470 330 330 680 390 270 270 560 560 680 470 330 330 680 390 270 270 560 560 680 470 330 330 680 390 270 270 100,000 100,000 100,000 6,800 3,300 6,800 2,700 100,000 100,000 6,800 4,700 3,300 3,300 6,800 3,900 2,700 2,700 100,000 100,000 6,800 4,700 3,300 3,300 6,800 3,900 2,700 2,700 100,000 100,000 6,800 4,700 3,300 3,300 6,800 3,900 2,700 2,700 R1 (ohms) 510 680 910 1,200 1,200 2,200 2,200 910 1,100 1,200 1,200 1,200 1,500 2,200 2,200 2,200 2,700 910 1,100 1,200 1,200 1,200 1,500 2,200 2,200 2,200 2,700 910 1,100 1,200 1,200 1,200 1,500 2,200 2,200 2,200 2,700 *Please contact factory for loop filter values not listed in the above table (info@pulsecore.com; or Ext. 17 or 25) Oct, 2002 Revision F PulseCore - A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 * Santa Clara * CA * 95054 Tel (408) 748-6988 * Fax (408) 748-0009 http://www.pulsecore.com 3 of 3 (R) Final Specification P2781/82/84 Alliance Semiconductor SPREAD SPECTRUM SELECTION The P278xA performs Zero Cycle Slip when sets at low % spreading. This allows no occurrence of system timing error. The optimal setting should minimize system EMI to the fullest without affecting system performance. The spreading is described as a percentage deviation of the center frequency (Note: the center frequency is the frequency of the external reference input on CLKIN, Pin 1). Example: The P2781A is designed for PC peripheral, networking, notebook PC, and LCD monitor applications. It is optimized for operation between 3 to 78 MHz range. The P2781A's spread % selection is determined by the external LF value specified in Table 2. Table 1 specifies the input frequency range. The external LF allows the user to fine tuning the spread % to optimize the EMI reduction benefits of the spread spectrum. Figure 3 - P278xA Application Schematic 16MHz 1 CLKIN VDD 8 2 XOUT FS0 7 3 FS1 ModOUT 6 4 LF VSS 5 0.1uF 820 Ohm R1 C2 100,000 pF +3.3V P2781A Modulated 16MHz with +/-0.5% BW to target chip C1 560pF 0 Ohm Note: Both logic input pins FS1 and FS0 have to be connected to either VDD or VSS by a low impedance connection such as a printed circuit board trace or zero ohms resistor. Do not leave them floating. Oct, 2002 Revision F PulseCore - A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 * Santa Clara * CA * 95054 Tel (408) 748-6988 * Fax (408) 748-0009 http://www.pulsecore.com 4 of 4 (R) Final Specification Alliance Semiconductor P2781/82/84 EMC SOFTWARE SIMULATION By using PulseCore Semiconductor, Inc.'s proprietary EMC simulation software - EMI-lator(R), radiated system level EMI analysis can be made easier to allow a quantitative assessment on PulseCore's EMI reduction products. The simulation engine of this EMC software has already been characterized to correlate with the electrical characteristics of PulseCore EMI reduction IC's. Figure 4 below is an example of the simulation result. Please visit our web site at www.pulsecore.com for information on how to obtain a free copy and demonstration of EMI-lator(R). Figure 4 - Simulation Result from EMI-lator(R) Oct, 2002 Revision F PulseCore - A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 * Santa Clara * CA * 95054 Tel (408) 748-6988 * Fax (408) 748-0009 http://www.pulsecore.com 5 of 5 (R) Final Specification P2781/82/84 Alliance Semiconductor ABSOLUTE MAXIMUM RATINGS P278XX Symbol VDD, VIN TSTG TA Parameter Voltage on any pin with respect to GND Storage Temperature Operating Temperature Rating -0.5 to +7.0 -65 to +125 0 to +70 Unit V C C DC ELECTRICAL CHARACTERISTICS P2781X at VDD=3.3V and Temp = +25oC Symbol Parameter VIL VIH IIL IXOL Input Low Voltage Input High Voltage Input Low Current (internal input pull-up resistor on FS0 and FS1) Input High Current (internal input pull-up resistor on FS0 and FS1) XOUT Output Low Current IXOH XOUT Output High Current VOL VOH Output Low Voltage (VDD = 3.3V, IOL = 20 mA) Output High Voltage (VDD = 3.3V, IOH = 20 mA) Static Supply Current Typical Dynamic Supply Current (25pF scope probe loading) Operating Voltage IIH IDD ICC VDD tON ZOUT Power Up Time (CLOOP=0.1F, at 16MHz, first locked clock cycle after power up) Clock Output Impedance (at 16MHz) Min Typ Max Unit GND - 0.3 2.0 - 60 0.8 VDD + 0.3 - V V A - 0 - A - 10 - mA - 10 - mA 2.5 - 0.4 - V V 5.2 @ 3 MHz 3.0 - 3 mA mA 3.3 7 21.2 @ 82 MHz 3.6 - - 28 - V mS AC ELECTRICAL CHARACTERISTICS at VDD=3.3V and Temp = +25oC Symbol Parameter f IN f OUT Input Frequency: P278XX Output Frequency: P2781X P2782X P2784X[AHZ1] Output Rise Time (measured at 0.8V to 2.0V, 25pF scope probe loading) Output Fall Time (measured at 2.0V to 0.8V, 25pF scope probe loading) Jitter (cycle to cycle, +/-6sigma, 1000 sweeps, +/-0.5% spread, I/O Frequency = 16 MHz) Output Duty Cycle Deviation (error from 50% duty cycle, 25pF scope probe loading) tLH P278XX tHL P278XX tJC P2781X tD P2781X Oct, 2002 Revision F Min Typ 3 3 6 12 +/-1 @ 3 MHz Max Unit 78 78 156 312 MHz MHz 1 ns 1 ns +/250 ps +/-2 @ 82 MHz % PulseCore - A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 * Santa Clara * CA * 95054 Tel (408) 748-6988 * Fax (408) 748-0009 http://www.pulsecore.com 6 of 6 (R) Final Specification P2781/82/84 Alliance Semiconductor F Frequency deviation tolerance from BW% stated in Table2 P278XX -20 0 +20 % Figure 5 - Mechanical Package Outline (8 Pin SOIC) C L X278XA LOT NUMBER YYWW H E a D A2 B e A A1 INCHES MILLIMETERS SYMBOL MIN NOR MAX MIN NOR MAX 0.057 0.064 0.071 1.45 1.63 1.80 A 0.004 0.007 0.010 0.10 0.18 0.25 A1 0.053 0.061 0.069 1.35 1.55 1.75 A2 0.012 0.016 0.020 0.51 0.41 0.31 B 0.004 0.006 0.001 0.10 0.15 0.25 C 0.186 0.194 0.202 4.72 4.92 5.12 D 0.148 0.156 0.164 3.75 3.95 4.15 E 0.050 BSC 1.27 BSC e 0.224 0.236 0.248 5.70 6.00 6.30 H 0.012 0.020 0.028 0.30 0.50 0.70 L 0 5 8 0 5 8 a Note: Controlling dimensions are millimeters. SOIC - 0.074 grams unit weight Figure 6 - Mechanical Package Outline (8 Pin TSSOP) C X 278xx Lot # YYWW L H E a D A2 B Oct, 2002 Revision F e A1 A INCHES MILLIMETERS SYMBOL MIN NOR MAX MIN NOR MAX 0.047 1.10 A 0.002 0.006 0.05 0.15 A1 0.031 0.039 0.041 0.80 1.00 1.05 A2 0.007 0.012 0.19 0.30 B 0.004 0.008 0.09 0.20 C 0.114 0.118 0.122 2.90 3.00 3.10 D 0.169 0.173 0.177 4.30 4.40 4.50 E 0.026 BSC 0.65 BSC e 0.244 0.252 0.260 6.20 6.40 6.60 H 0.018 0.024 0.030 0.45 0.60 0.75 L 0 8 0 8 a Note: Controlling dimensions are millimeters. TSSOP - 0.034 grams unit weight PulseCore - A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 * Santa Clara * CA * 95054 Tel (408) 748-6988 * Fax (408) 748-0009 http://www.pulsecore.com 7 of 7 (R) Final Specification P2781/82/84 Alliance Semiconductor Ordering Information: X 278XX- 08 XX Package ST=SOIC in Tube SR=SOIC in Tape and Reel TT=TSSOP in Tube TR=TSSOP in Tape and Reel Device Pin Count Device Number Flow P=Commercial Temperature Range (0C to 70C) I =Industrial Temperature Range (-25C to 85C) A = Automotive Temperature Range (-40C to 125C) Available Ordering Numbers: Ordering Number X278XA-08ST X278XA-08SR X278XA-08TT X278XA-08TR X278XB-08TT X278XB-08TR Oct, 2002 Revision F Marking X278XA X278XA X278XA X278XA X278XB X278XB Package Type 8 PIN SOIC, TUBE 8 PIN SOIC, TAPE & REEL 8 PIN TSSOP, TUBE 8 PIN TSSOP, TAPE & REEL 8 PIN TSSOP, TUBE 8 PIN TSSOP, TAPE & REEL QTY / Reel 2,500 2,500 2,500 Temperature See flow See flow See flow See flow See flow See flow PulseCore - A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 * Santa Clara * CA * 95054 Tel (408) 748-6988 * Fax (408) 748-0009 http://www.pulsecore.com 8 of 8 (R) Final Specification Alliance Semiconductor Document Information History REVISION DCR # ISSUE DATE E 221 Sep. 13, 2002 P2781/82/84 DESCRIPTION OF CHANGE -Added P2781/82/84B as the alternative 8 TSSOP pinout -Part numbering information -AC characteristics to include output frequency for P2782/84 "Licensed under U.S. Patent Nos. 5,488,627 and 5,631,920" Preliminary data sheet. Specifications subject to change without notice. Oct, 2002 Revision F PulseCore - A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 * Santa Clara * CA * 95054 Tel (408) 748-6988 * Fax (408) 748-0009 http://www.pulsecore.com 9 of 9