ASM3X2105A October 2003 rev 1.0 Features signals. The ASM3X2105A allows significant system cost FCC approved method of EMI attenuation. savings by reducing the number of circuit board layers Generates a 1X or ½ X low EMI spread spectrum ferrite beads, shielding and other passive components clock of the input frequency. that are traditionally required to pass EMI regulations. Input frequency range: 6MHz to 10 MHz. Internal loop filter minimizes external components The ASM3X2105A uses the most efficient and optimized and board space. modulation profile approved by the FCC and is Frequency deviation: Maximum ± 1%. implemented in a proprietary all digital method. SSON# control pin for spread spectrum enable and disable options. The ASM3X2105A modulates the output of a single PLL Low cycle-to-cycle jitter. in order to “spread” the bandwidth of a synthesized clock, 5.0V ± 5% operating voltage range. and more importantly, decreases the peak amplitudes of TTL or CMOS compatible outputs. its harmonics. This results in significantly lower system Ultra-low power CMOS design. EMI compared to the typical narrow band signal produced Available in 8-pin SOIC and TSSOP. by oscillators and most frequency generators. Lowering EMI by increasing a signal’s bandwidth is called ‘spread Product Description The ASM3X2105A is a versatile spread spectrum frequency modulator designed specifically for input clock frequencies from 6MHz to 12MHz. The ASM3X2105A can generate an EMI reduced clock from crystal, ceramic resonator, or system clock. The ASM3X2105A offers frequency deviation of ± 1%. spectrum clock generation’. Applications The ASM3X2105A is targeted towards EMI management for high speed digital applications such as PC peripheral devices, consumer electronics and embedded controller The ASM3X2105A reduces electromagnetic interference systems. (EMI) at the clock source, allowing system wide reduction of EMI of down stream clock and data dependent Block Diagram SR0 SSON# VDD DIV2 PLL Modulation XIN Crystal Oscillator Frequency Divider XOUT Feedback Divider Phase Detector Loop Filter 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. ASM3X2105A October 2003 rev 1.0 Pin Configuration XIN /CLK 1 XOUT 2 8 VDD 7 MODOUT ASM3X2105A DIV2 3 6 SSON# VSS 4 5 SR0 Pin Description Pin# Pin Name Type 1 XIN/CLK I 2 XOUT O 3 DIV2 I 4 VSS P 5 SR0 I 6 SSON# I 7 8 MODOUT VDD O P Description Crystal connection or external reference frequency input. This pin has dual functions. It can be connected to either 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 normal output mode or divide-by-2 output mode. When this pin is HIGH, the frequency of the output clock is the same as the input clock frequency. When it is tied LOW, the output frequency is half the input clock frequency. This pin has an internal pull-up resistor. Ground to entire chip. Digital logic input used to select Spreading Range (Refer Spread Deviation Table). This pin has an internal pull-up resistor. Digital logic input used to enable Spread Spectrum function (Active LOW). Spread Spectrum function enabled when LOW, disabled when HIGH. This pin has an internal pull-low resistor. Spread spectrum low EMI output. Power supply for the entire chip (5V). Spread Deviation Table SR0 1 0 Spread Deviation (%) ±1 Reserved Low Frequency EMI Reduction Notice: The information in this document is subject to change without notice. 2 of 10 ASM3X2105A October 2003 rev 1.0 Spread Spectrum Spreading the spectrum of the signal reduces the system EMI. 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, Pin1). Example: The ASM3X2105A is designed for communications, digital video and imaging applications. It is not only optimized for operation in the 6MHz – 12MHz range, but its output frequency can be extended down to one half of the input clock frequency using the divide-by-two feature. This feature extends low frequency operation to as low as 3MHz. Setting pin 3 low (DIV2=0; divide-by-two mode) sets the output frequency (MODOUT) to half the frequency of the input clock (CLKIN). This is a simple way to generate a spread spectrum modulated low frequency clock when only a higher frequency signal is available. If you want the output frequency to be the same as the input, you can either set DIV2=1 or leave it unconnected. +5V 8.832MHz Crystal 1 CLKIN VDD 8 2 XOUT MODOUT 7 3 DIV2 SSON# 6 4 VSS SR0 5 0.1µF Modulated 4.416MHz is connected to CLK input pin of the system ASM3X2105A Low Frequency EMI Reduction Notice: The information in this document is subject to change without notice. 3 of 10 ASM3X2105A October 2003 rev 1.0 EMC Software Simulation By using Alliance’s proprietary EMC simulation software – EMI-Lator®, radiated system level EMI analysis can be made easier, allowing quantitative measure on the benefits of Alliance’s EMI reduction products. The simulation engine of this EMC software has already been characterized to correlate with the electrical characteristics of Alliance EMI reduction ICs. The figure below is an illustration of this simulation result. Please visit our website at www.alsc.com for information on how to obtain a free copy and demonstration of EMI-Lator ®. Simulation results From EMI-Lator® Low Frequency EMI Reduction Notice: The information in this document is subject to change without notice. 4 of 10 ASM3X2105A October 2003 rev 1.0 Absolute Maximum Ratings Symbol VDD, VIN Parameter Voltage on any pin with respect to GND Rating Unit -0.5 to + 7.0 V TSTG Storage temperature -65 to +125 °C TA Operating temperature 0 to 70 °C 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 Symbol Parameter VIL Input low voltage VIH IIH Input high voltage Input low current (pull-up resistors on inputs SR0 and DIV2) Input high current (pull-down resistor on input SSON#) IXOL IIL Min Typ Max Unit GND – 0.3 - 0.8 V 2.0 - VDD + 0.3 V 44 µA 66 µA XOUT output low current (@ 4.0V, VDD = 5V) 3 mA IXOH XOUT output high current (@2.5V, VDD = 5V) 3 VOL Output low voltage (VDD = 5V, IOL = 20mA) VOH 2.5 IDD Output high voltage (VDD = 5V, IOH = 20mA) Dynamic supply current normal mode (5V, 8MHz and 15pF loading) Static supply current standby mode VDD Operating voltage 4.75 5.0 5.25 V tON Power up time (first locked clock cycle after power up) - 0.18 - mS ZOUT Clock out impedance - 50 - Ω ICC mA 0.4 Low Frequency EMI Reduction Notice: The information in this document is subject to change without notice. V V 40 mA 40 µA 5 of 10 ASM3X2105A October 2003 rev 1.0 AC Electrical Characteristics Symbol Parameter Min Typ Max Unit fIN Input frequency 6 - 10 MHz MODOUT Output frequency 6 - 10 MHz tLH* Output rise time (measured at 0.8V to 2.0V) - 440 - ps tHL* Output fall time (measured at 2.0V to 0.8V) - 300 - ps tJC Jitter (cycle to cycle) - - 360 ps 50 55 % tD Output duty cycle 45 * VDD = +5V, Input Frequency = 8MHz, tLH and tHL are measured into a capacitive load of 15pF Low Frequency EMI Reduction Notice: The information in this document is subject to change without notice. 6 of 10 ASM3X2105A October 2003 rev 1.0 Package Information 8-Pin SOIC (Pb Free Parts) H E D A2 A C θ e A1 B Symbol Dimensions in inches D L Dimensions in millimeters Min Max Min Max A 0.057 0.071 1.45 1.80 A1 0.004 0.010 0.10 0.25 A2 0.053 0.069 1.35 1.75 B 0.012 0.020 0.31 0.51 C 0.004 0.01 0.10 0.25 D 0.186 0.202 4.72 5.12 E 0.148 0.164 3.75 4.15 e 0.050 BSC 1.27 BSC H 0.224 0.248 5.70 6.30 L 0.012 0.028 0.30 0.70 θ 0° 8° 0° 8° Low Frequency EMI Reduction Notice: The information in this document is subject to change without notice. 7 of 10 ASM3X2105A October 2003 rev 1.0 8-Pin TSSOP H E D A2 A C θ e A1 L B Dimensions in inches Symbol Min A 0.047 A1 0.002 0.006 0.05 0.15 A2 0.031 0.041 0.80 1.05 B 0.007 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 Max Dimensions in millimeters Min Max 1.10 0.026 BSC 0.65 BSC H 0.244 0.260 6.20 6.60 L 0.018 0.030 0.45 0.75 θ 0° 8° 0° 8° Low Frequency EMI Reduction Notice: The information in this document is subject to change without notice. 8 of 10 ASM3X2105A October 2003 rev 1.0 Ordering Codes Part Number ASM3X2105AFTR ASM3X2105AFT ASM3X2105AFSR ASM3X2105AFS Package 8-PIN TSSOP 8-PIN TSSOP 8-PIN SOIC 8-PIN SOIC TAPE AND REEL TUBE TAPE AND REEL TUBE Device Ordering Information A S M 3 X 2 1 0 5 A F T R OR - SOT23/T/R TT – TSSOP, TUBE TR - TSSOP, T/R VT – TVSOP, TUBE VR – TVSOP, T/R ST – SOIC, TUBE SR - SOIC, T/R QR – QFN, T/R QT - QFN, TUBE BT - BGA, TUBE BR – BGA, T/R F = Pb FREE PART NUMBER X = Automotive I = Industrial 1 – reserved 2 - Non PLL based 3 – EMI Reduction 4 – DDR support products 5 – STD Zero Delay Buffer P or n/c = Commercial 6 – power management 7 – power management 8 – power management 9 – Hi performance 0 - reserved Alliance Semiconductor Mixed Signal Product Low Frequency EMI Reduction Notice: The information in this document is subject to change without notice. 9 of 10 ASM3X2105A October 2003 rev 1.0 Alliance Semiconductor Corporation 2595, Augustine Drive, Santa Clara, CA 95054 Tel# 408-855-4900 Fax: 408-855-4999 www.alsc.com Copyright © Alliance Semiconductor All Rights Reserved Preliminary Information Part Number: ASM3X2105A Document Version: v1.0 © 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. 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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. Low Frequency EMI Reduction Notice: The information in this document is subject to change without notice. 10 of 10