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| February 2005 rev 0.4 ASM3P2508SP Clock Synthesizer and Frequency Generator with Peak EMI reduction Features Dual PLL based Architecture Operates with a 3.3V 0.3V supply. Generates an EMI optimized Spread Spectrum PCI Clock output Generates a high accuracy non Spread T1 clock of 25ppm accuracy. Generates a non spread system reference clock Low power CMOS design. Input frequency: 25 MHz. Outputs: Sys_ REF_CLK: 20 MHz T1 Clock: 25 MHz (25 ppm) PCI_CLK: 33.33MHz Spread Spectrum Frequency deviation: -0.5% (Typ). Available in 8L SOIC Package. The ASM3P2508SP uses the most efficient and optimized modulation profile approved by the FCC. ASM3P2508SP modulates the output of a PLL in order to "spread" the bandwidth of a synthesized clock, and more importantly, decreases the peak amplitudes of its harmonics. This results in a 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' (SSCG). In addition to the SSCG output, ASM3P2508SP generates two high accuracy clock signals T1 Clock @ 25.00MHz with +/- 25ppm stability, and a 20MHz Sys_ REF_CLK. Applications The ASM3P2508SP is targeted towards Consumer, Industrial, Data and Telecommunications applications. Product Description The ASM3P2508SP is a versatile Dual PLL based Clock Synthesizer and Frequency Generator optimised and designed specifically for three clock frequencies. The PCI_CLK output from ASM3P2508SP reduces Key Specifications Description Supply voltages Input Frequency Cycle-to-Cycle Jitter Output Duty Cycle Output Rise and Fall Time SSC Modulation Rate SSC Frequency Deviation Specification VDD = 3.3V 0.3V 25 MHz 175 pS ( Max) 45/55% 1.1 nS (Max) 30KHz (Typ) -0.5% (Typ) electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of all clock dependent signals. ASM3P2508SP allows significant system cost savings by reducing the number of circuit board layers, ferrite beads & shielding that are traditionally required to pass EMI regulations. Block Diagram PWRDNB VDD T1_CLK Input Divider PLL 1 Output Divider Sys_REF_CLK XIN/CLKIN Osc XOUT PLL 2 Output Divider PCI_CLK Modulation 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. February 2005 rev 0.4 Pin Configuration XIN/CLKIN 1 8 7 ASM3P2508SP T1_CLK VSS PCI_CLK PWRDNB XOUT 2 ASM3P2508SP VDD 3 Sys_REF_CLK 4 6 5 Pin Description Pin# 1 2 3 4 5 6 7 8 Pin Name XIN/CLKIN XOUT VDD Sys_REF_CLK PWRDNB PCI_CLK VSS T1_CLK Type I O P O I O P O Description Crystal connection or external reference frequency 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. Power supply for the entire chip PLL 1 output System Reference Clock @ 20MHz Power-down control pin. Pull low to enable power-down mode. Connect to VDD if not used. Power -down Mode shuts off all the Outputs. PLL 2 Spread spectrum clock output @ 33.33MHz Ground to entire chip. Connect to system ground Reference output T1 Clock @ 25MHz Typical Modulation Profile Absolute Maximum Ratings Symbol VDD, VIN TSTG TA Ts TJ TDV Storage temperature Operating temperature Max. Soldering Temperature (10 sec) Junction Temperature Static Discharge Voltage (As per JEDEC STD 22- A114-B) Parameter Voltage on any pin with respect to Ground Rating -0.5 to +7.0 -65 to +125 0 to 70 260 150 2 Unit V C C C C KV Note: These are stress ratings only and are not implied for functional use. Exposure to absolute maximum ratings for prolonged periods of time may affect device reliability. Clock Synthesizer and Frequency Generator with Peak EMI reduction Notice: The information in this document is subject to change without notice. 2 of 7 February 2005 rev 0.4 DC Electrical Characteristics (Test condition: All parameters are measured at room temperature (+25C) unless otherwise stated) ASM3P2508SP Symbol VIL VIH IIL IIH IXOL IXOH VOL VOH IDD ICC VDD tON ZOUT Input low voltage Input high voltage Input low current Input high current Parameter Min VSS - 0.3 2.0 - - - - - 2.5 - - 3.0 - - Typ - - - - 3 3 - - - 20 3.3 - 50 Max 0.8 VDD + 0.3 -35 35 - - 0.4 - 10 _ 3.6 5 - Unit V V A A mA mA V V A mA V mS XOUT output low current (@0.4V, VDD=3.3V) XOUT output high current (@2.5V, VDD=3.3V) Output low voltage (VDD = 3.3 V, IOL = 20 mA) Output high voltage (VDD = 3.3 V, IOH = 20 mA) Static supply current * Dynamic supply current (3.3V, 33.33MHz, 25MHz , 20MHz and 15pF loading) Operating voltage Power-up time (first locked cycle after power up)** Clock output impedance * PWRDNB pin is pulled low ** VDD and XIN/CLKIN input are stable, PWRDNB pin is made high from low. AC Electrical Characteristics Symbol XIN PCI_CLK T1_CLK Sys_REF_CLK PCI_CLK (SSCG) tLH* tHL* tJC tD Modulation Rate Deviation Output rise time (measured at 0.8V to 2.0V) Output fall time (measured at 2.0V to 0.8V) Jitter (cycle to cycle) Output duty cycle Output frequency Input frequency Parameter Min - - 24.999375 - - - 0.7 0.6 - 45 Typ 25 33.33 25 20 30 -0.5 0.9 0.8 150 50 Max - - 25.000625 - - - 1.0 1.0 175 55 Unit MHz MHz MHz KHz % nS nS pS % * tLH and tHL are measured into a capacitive load of 15pF Clock Synthesizer and Frequency Generator with Peak EMI reduction Notice: The information in this document is subject to change without notice. 3 of 7 February 2005 rev 0.4 Typical Crystal Oscillator Circuit ASM3P2508SP Crystal R1 = 510 C1 = 27 pF C2 = 27 pF Typical Crystal Specifications Fundamental AT cut parallel resonant crystal Nominal frequency Frequency tolerance Operating temperature range Storage temperature Load capacitance Shunt capacitance ESR 25 MHz 25 ppm or better at 25C -25C to +85C -40C to +85C 18pF 7pF maximum 25 Clock Synthesizer and Frequency Generator with Peak EMI reduction Notice: The information in this document is subject to change without notice. 4 of 7 February 2005 rev 0.4 Package Information 8-lead (150-mil) SOIC Package ASM3P2508SP E H D A2 A e B A 1 C L D Dimensions Symbol Min A1 A A2 B C D E e H L Inches Max 0.010 0.069 0.059 0.020 0.010 0.004 0.053 0.049 0.012 0.007 Millimeters Min Max 0.10 1.35 1.25 0.31 0.18 4.90 BSC 3.91 BSC 1.27 BSC 6.00 BSC 0.41 0 1.27 8 0.25 1.75 1.50 0.51 0.25 0.193 BSC 0.154 BSC 0.050 BSC 0.236 BSC 0.016 0 0.050 8 Clock Synthesizer and Frequency Generator with Peak EMI reduction Notice: The information in this document is subject to change without notice. 5 of 7 February 2005 rev 0.4 Ordering Information Part Number ASM3P2508SP-08ST ASM3P2508SP-08SR ASM3P2508SPF-08ST ASM3P2508SPF-08SR ASM3I2508SP-08ST ASM3I2508SP-08SR ASM3I2508SPF-08ST ASM3I2508SPF-08SR ASM3P2508SP Marking 3P2508SP 3P2508SP 3P2508SPF 3P2508SPF 3I2508SP 3I2508SP 3I2508SPF 3I2508SPF Package Type 8-Pin SOIC, TUBE 8-Pin SOIC, TAPE & REEL 8-Pin SOIC, TUBE, Pb free 8-Pin SOIC, TAPE & REEL, Pb free 8-Pin SOIC, TUBE 8-Pin SOIC, TAPE & REEL 8-Pin SOIC, TUBE, Pb free 8-Pin SOIC, TAPE & REEL, Pb free Temperature Commercial Commercial Commercial Commercial Industrial Industrial Industrial Industrial Device Ordering Information ASM3P2508SPF-08TR OR - TSOT23 -6, T/R TT - TSSOP, TUBE TR - TSSOP, T/R VT - TVSOP, TUBE VR - TVSOP, T/R ST - SOIC, TUBE AR - SSOP, T/R AT - SSOP, TUBE SR - SOIC, T/R QR - QFN, T/R QT - QFN, TRAY BT - BGA, TRAY BR - BGA, T/R UR - SOT-23,T/R DR - QSOP, T/R DT - QSOP, TUBE PIN COUNT LEAD FREE PART PART NUMBER X = Automotive I = Industrial P or n/c = Commercial (-40C to +125C) (-40C to +85C) (0C to +70C) 1 - reserved 2- Non PLL based 3 - EMI Reduction 4 - DDR support products 5 - STD Zero Delay Buffer 6 - power management 7 - power management 8 - power management 9 - Hi performance 0 - reserved Alliance Semiconductor Mixed Signal Product Licensed under U.S Patent #s 5,488,627 and 5,631,921 Clock Synthesizer and Frequency Generator with Peak EMI reduction Notice: The information in this document is subject to change without notice. 6 of 7 February 2005 rev 0.4 ASM3P2508SP Alliance Semiconductor Corporation 2595, Augustine Drive, Santa Clara, CA 95054 Tel# 408-855-4900 Fax: 408-855-4999 www.alsc.com Copyright (c) Alliance Semiconductor All Rights Reserved Preliminary Information Part Number: ASM3P2508SP Document Version: v0.4 Note: This product utilizes US Patent # 6,646,463 Impedance Emulator Patent issued to Alliance Semiconductor, dated 11-11-2003 (c) Copyright 2004 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. Clock Synthesizer and Frequency Generator with Peak EMI reduction Notice: The information in this document is subject to change without notice. 7 of 7 |
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