P2781/82/84 July 2005 rev 1.5 General Purpose EMI Reduction IC Features other digital video and imaging applications. The P278xA reduces electromagnetic interference (EMI) at the clock source, which provides system wide reduction of EMI of all clock dependent signals. The P278xA allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. Provides up to 15dB of EMI suppression FCC approved method of EMI attenuation Generates a 1X, 2X, and 4X low EMI spread spectrum clock of the input frequency Input frequency range from 3 to 78MHz External loop filter for spread % adjustment Spreading ranges from ±0.25% to ±5.0% Ultra low cycle-to-cycle jitter Zero-cycle slip 3.3V operating voltage range 10 mA output drives TTL or CMOS compatible outputs Ultra-low power CMOS design P278XA is available in 8 pin SOIC and TSSOP Packages Available for industrial and automotive temperature ranges. The P278xA uses the most efficient and optimized modulation profile approved by the FCC. The P278xA 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. Applications Product Description The P278xA is a versatile spread spectrum frequency modulator designed specifically for digital camera and The P278xA is targeted towards MFP, xDSL, fax modem, set-top box, USB controller, DSC, and embedded systems. FS0 Block Diagram FS1 LF VDD PLL Modulation XIN /CLKIN XOUT Crystal Oscillator Frequency Divider Feedback Divider Phase Detector VCO Output Divider ModOUT VSS Alliance Semiconductor 2575, Augustine Drive • Santa Clara, CA • Tel: 408.855.4900 • Fax: 408.855.4999 • www.alsc.com Notice: The information in this document is subject to change without notice. P2781/82/84 July 2005 rev 1.5 Pin Configuration XIN / CLKIN 1 XOUT 2 FS1 LF 8 VDD 7 FS0 3 6 ModOUT 4 5 VSS P278XA-08S P278XA-08T Standard pin Configuration offered in both 8 pin SOIC and TSSOP Packages Pin Description (P278XA) Pin# Pin Name Type Description Connect to crystal or clock input. This pin has dual functions. It can be connected either to an external crystal or an external reference clock. Crystal connection. If using an external reference, this pin must be left unconnected. Digital logic input used to select input frequency range (see the Input Frequency Selection Table). This pin has an internal pull-up resistor. External Loop Filter for the PLL. By changing the value of the CRC circuit, the percentage spread can be adjusted accordingly. See the Loop Filter Selection Table for detail value. 1 XIN/CLKIN I 2 XOUT O 3 FS1 I 4 LF I 5 VSS I Ground Connection. Connect to system ground. 6 ModOUT O Spread Spectrum Clock Output. 7 FS0 I Digital logic input used to select input frequency range (see the Input Frequency Selection Table). This pin has an internal pull-up resistor. 8 VDD P Connect to +3.3 V Input Frequency Selection Table FS1 FS0 Input (MHz) 0 0 1 1 0 1 0 1 3 to 9 10 to 19 20 to 38 39 to 78 Output Frequency Scaling (MHz) P2781A P2782A P2784A 3 to 9 10 to 19 20 to 38 39 to 78 6 to 18 20 to 38 40 to 76 78 to 156 12 to 36 40 to 76 80 to 152 156 to 312 General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. Modulation Rate (KHz) Fin / 128 Fin / 256 Fin / 512 Fin / 1024 2 of 11 P2781/82/84 July 2005 rev 1.5 Loop Filter Selection Table VDD 3.3V Contact Alliance for loop values that are not listed in the table and for component selection values for industrial and automotive temperatures. 1 1 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 0 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 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 1 BW = ±0.75% 1 BW = ±1.00% C1 (pF) C2 (pF) R1 (ohm) C1 (pF) C2 (pF) R1 (ohm) C1 (pF) 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 330,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 220 270 390 510 620 820 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 1,200 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 330,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 100,000 300 390 560 750 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 1,800 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 270 C2 (pF) R1 (ohm) 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) R1 (ohm) 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 2,700 510 680 910 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 1 The BW value is representative of typical conditions General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. 3 of 11 P2781/82/84 July 2005 rev 1.5 Spread Spectrum Selection The P278xA performs Zero Cycle Slip when set at low percentage 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.) The P2781A is designed for PC peripheral, networking, notebook PC, and LCD monitor applications. It is optimized for operation between 3 to 78MHz range. In the following application schematic example, the P2781A spread percentage selection is determined by the external LF value specified in the Loop Filter Selection Table. The Input Frequency Selection Table specifies the input frequency range. The external LF allows the user to fine tune the spread percentage to optimize the EMI reduction benefits of the spread spectrum. 16 MHz 1 XIN/CLKIN VDD 8 2 XOUT 3 FS1 C2 R1 C1 FS0 7 0.1µF ModOUT 6 4 LF 0 Ohm 2.2 K +3.3V Modulated 16MHz Clock To target Chip VSS 5 P2781A Note: Both logic input pins FS1 and FS0 have to be connected to either VDD or VSS. Do not leave them floating. General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. 4 of 11 P2781/82/84 July 2005 rev 1.5 Absolute Maximum Ratings Symbol VDD Parameter Supply voltage, DC Rating Unit (VSS – 0.5) to 7 V VI Input voltage, DC (VSS-0.5) to (VDD+0.5) V VO Output voltage, DC (VSS-0.5) to (VDD + 0.5) V IIK Input clamp current (VI<0 or VI>VDD) -50 to +50 mA IOK Output clamp current (VI<0 or VI>VDD) -50 to +50 mA TS Storage temperature -65 to +125 °C TA Ambient temperature range, under bias -55 to 125 °C TJ Junction temperature 150 °C Lead temperature (soldering 10 sec) Input static discharge voltage protection (As per JEDEC STD22- A114-B) 260 °C 2 kV Note: These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for extended periods may affect device reliability. DC Electrical Characteristics (Test condition: All parameters are measured at room temperature (+25°C) unless otherwise stated) Symbol Parameter Min Typ Max Unit VSS – 0.3 - 0.8 V 2.0 - VDD +0.3 V - 60 - µA - 60 - µA - 10 - mA - 10 - mA Output low voltage (VDD = 3.3V, IOL = 20mA) - - 0.4 V VOH Output high voltage (VDD = 3.3V, IOH = 20mA) 2.5 - - V IDD Static supply current Typical dynamic supply current (25pF scope probe loading) Operating voltage - 3 - mA 5.2 at 3MHz - 21.2 at 82MHz mA 3.0 3.3 3.6 V VIL Input low voltage VIH IXOL 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 IIL IIH ICC VDD General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. 5 of 11 P2781/82/84 July 2005 rev 1.5 AC Electrical Characteristics Symbol fIN fOUT tLH P278XA tHL P278XA tJC P2781A tD P2781A ∆F P278XA Parameter Input frequency: P278XA Output frequency: P2781A P2782A P2784A Output rise time (measured at 0.8 V to 2.0 V, 25pF scope probe loading) Output fall time (measured at 2.0 V to 0.8 V, 25 pF scope probe loading) Jitter (cycle to cycle, ± 6sigma, 1000 sweeps, ± 0.5% spread, I/O frequency = 16MHz) Output duty cycle deviation (error from 50% duty cycle, 25pF scope probe loading) Frequency deviation tolerance from BW% stated in the Loop Filter Selection Table Min Typ Max Unit 3 - 78 MHz 3 6 12 - 78 156 312 MHz - 1 - nS - 1 - nS - ±250 - pS ±1 at 3MHz - ±2 at 82MHz % -20 0 +20 % General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. 6 of 11 P2781/82/84 July 2005 rev 1.5 Package Information Mechanical Package Outline 8-Pin SOIC Package H E D A2 A C A1 D θ e L B Dimensions Symbol Inches Min Max Millimeters Min Max A1 0.004 0.010 0.10 0.25 A 0.053 0.069 1.35 1.75 A2 0.049 0.059 1.25 1.50 B 0.012 0.020 0.31 0.51 C 0.007 0.010 0.18 0.25 D 0.193 BSC 4.90 BSC E 0.154 BSC 3.91 BSC e 0.050 BSC 1.27 BSC H 0.236 BSC 6.00 BSC L 0.016 0.050 0.41 1.27 θ 0° 8° 0° 8° Note: Controlling dimensions are millimeters SOIC - 0.074 grams unit weight General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. 7 of 11 P2781/82/84 July 2005 rev 1.5 Mechanical Package Outline 8-Pin TSSOP Package H E D A2 A C θ e A1 L B Dimensions Symbol Inches Min Millimeters Max A Min Max 0.043 1.10 A1 0.002 0.006 0.05 0.15 A2 0.033 0.037 0.85 0.95 B 0.008 0.012 0.19 0.30 c 0.004 0.008 0.09 0.20 D 0.114 0.122 2.90 3.10 E 0.169 0.177 4.30 4.50 e 0.026 BSC 0.65 BSC H 0.252 BSC 6.40 BSC L 0.020 0.028 0.50 0.70 θ 0° 8° 0° 8° Note: Controlling dimensions are millimeters TSSOP - 0.0325 grams unit weight General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. 8 of 11 P2781/82/84 July 2005 rev 1.5 Ordering Codes Ordering # Marking Package Type P278XA-08ST P278XA 8 PIN SOIC, TUBE P278XA-08SR P278XA 8 PIN SOIC, TAPE & REEL P278XA-08TT P278XA 8 PIN TSSOP, TUBE P278XA-08TR P278XA 8 PIN TSSOP, TAPE & REEL P278XAF-08ST P278XAF 8 PIN SOIC, TUBE, Pb Free P278XAF-08SR P278XAF 8 PIN SOIC, TAPE AND REEL,Pb Free P278XAF-08TT P278XAF 8 PIN TSSOP, TUBE, Pb Free P278XAF-08TR P278XAF 8 PIN TSSOP, TAPE AND REEL, Pb Free P278XAG-08ST P278XAG 8 PIN SOIC, TUBE, Green P278XAG-08SR P278XAG 8 PIN SOIC, TAPE AND REEL, Green P278XAG-08TT P278XAG 8 PIN TSSOP, TUBE, Green P278XAG-08TR P278XAG 8 PIN TSSOP, TAPE AND REEL, Green I278XA-08ST I278XA 8 PIN SOIC, TUBE I278XA-08SR I278XA 8 PIN SOIC, TAPE & REEL I278XA-08TT I278XA 8 PIN TSSOP, TUBE I278XA-08TR I278XA 8 PIN TSSOP, TAPE & REEL I278XAF-08ST I278XAF 8 PIN SOIC, TUBE, Pb Free I278XAF-08SR I278XAF 8 PIN SOIC, TAPE AND REEL,Pb Free I278XAF-08TT I278XAF 8 PIN TSSOP, TUBE, Pb Free I278XAF-08TR I278XAF 8 PIN TSSOP, TAPE AND REEL, Pb Free I278XAG-08ST I278XAG 8 PIN SOIC, TUBE, Green I278XAG-08SR I278XAG 8 PIN SOIC, TAPE AND REEL, Green I278XAG-08TT I278XAG 8 PIN TSSOP, TUBE, Green I278XAG-08TR I278XAG 8 PIN TSSOP, TAPE AND REEL, Green X278XA-08ST X278XA 8 PIN SOIC, TUBE X278XA-08SR X278XA 8 PIN SOIC, TAPE & REEL X278XA-08TT X278XA 8 PIN TSSOP, TUBE X278XA-08TR X278XA 8 PIN TSSOP, TAPE & REEL X278XAF-08ST X278XAF 8 PIN SOIC, TUBE, Pb Free X278XAF-08SR X278XAF 8 PIN SOIC, TAPE AND REEL, Pb Free X278XAF-08TT X278XAF 8 PIN TSSOP, TUBE, Pb Free X278XAF-08TR X278XAF 8 PIN TSSOP, TAPE AND REEL, Pb Free X278XAG-08ST X278XAG 8 PIN SOIC, TUBE, Green X278XAG-08SR X278XAG 8 PIN SOIC, TAPE AND REEL, Green X278XAG-08TT X278XAG 8 PIN TSSOP, TUBE, Green X278XAG-08TR X278XAG 8 PIN TSSOP, TAPE AND REEL, Green QTY / Reel Temperature See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow 2,500 See flow See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 See flow See flow 2,500 General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. See flow 9 of 11 P2781/82/84 July 2005 rev 1.5 Device Ordering Information P 2 7 8 X A F - 0 8 X X Package: ST – SOIC, TUBE SR - SOIC, T/R TT – TSSOP, TUBE TR - TSSOP, T/R Pin Count F = LEAD FREE or RoHS COMPLIANT PART G = GREEN DEVICE NUMBER Flow: P = Commercial Temperature Range (0°C to 70°C) I = Industrial Temperature Range (-40°C to 85°C) X = Automotive Temperature Range (-40°C to 125°C) Licensed under US patent #5,488,627, #6,646,463 and #5,631,920 General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. 10 of 11 P2781/82/84 July 2005 rev 1.5 Alliance Semiconductor Corporation 2575, Augustine Drive, Santa Clara, CA 95054 Tel# 408-855-4900 Fax: 408-855-4999 www.alsc.com Copyright © Alliance Semiconductor All Rights Reserved Part Number: P2781/82/84 Document Version: 1.5 Note: This product utilizes US Patent # 6,646,463 Impedance Emulator Patent issued to Alliance Semiconductor, dated 11-11-2003 © Copyright 2003 Alliance Semiconductor Corporation. All rights reserved. Our three-point logo, our name and Intelliwatt are trademarks or registered trademarks of Alliance. All other brand and product names may be the trademarks of their respective companies. Alliance reserves the right to make changes to this document and its products at any time without notice. Alliance assumes no responsibility for any errors that may appear in this document. The data contained herein represents Alliance's best data and/or estimates at the time of issuance. Alliance reserves the right to change or correct this data at any time, without notice. If the product described herein is under development, significant changes to these specifications are possible. The information in this product data sheet is intended to be general descriptive information for potential customers and users, and is not intended to operate as, or provide, any guarantee or warrantee to any user or customer. Alliance does not assume any responsibility or liability arising out of the application or use of any product described herein, and disclaims any express or implied warranties related to the sale and/or use of Alliance products including liability or warranties related to fitness for a particular purpose, merchantability, or infringement of any intellectual property rights, except as express agreed to in Alliance's Terms and Conditions of Sale (which are available from Alliance). All sales of Alliance products are made exclusively according to Alliance's Terms and Conditions of Sale. The purchase of products from Alliance does not convey a license under any patent rights, copyrights; mask works rights, trademarks, or any other intellectual property rights of Alliance or third parties. Alliance does not authorize its products for use as critical components in life-supporting systems where a malfunction or failure may reasonably be expected to result in significant injury to the user, and the inclusion of Alliance products in such life-supporting systems implies that the manufacturer assumes all risk of such use and agrees to indemnify Alliance against all claims arising from such use. General Purpose EMI Reduction IC Notice: The information in this document is subject to change without notice. 11 of 11