September 2004 ASM3P2180A rev 1.0 Peak Reducing EMI Solution typical narrow band signal produced by oscillators and most clock generators. Lowering EMI by increasing a signal’s bandwidth is called spread spectrum clock generation. Features • Generates an EMI optimized clocking signal at the output. • Selectable output frequency range. • Single 1.25% or 2.4% down spread output. • Integrated loop filter components. • Operates with a 3.3V supply. • Low-power CMOS design. • Available in 8-pin SOIC and 8-pin TSSOP packages. The ASM3P2180A uses the most efficient and optimized modulation profile approved by the FCC and is implemented by using a proprietary all-digital method. Applications The ASM3P2180A is targeted towards notebook LCD displays, other displays using an LVDS interface, PC peripheral devices and embedded systems. Product Description The ASM3P2180A is a versatile Spread Spectrum frequency modulator designed specifically for a wide range of clock frequencies. The ASM3P2180A reduces electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of down stream clock and data dependent signals. The ASM3P2180A allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. Key Specifications Description Supply voltages Frequency range VDD = 3.3V ± 5% FS1=0 FS1=1 Cycle-to-cycle jitter Selectable spread percentage The ASM3P2180A modulates the output of a single PLL in order to “spread” the bandwidth of a synthesized clock, thereby decreasing the peak amplitudes of its harmonics. This results in significantly lower system EMI compared to the Specification Output duty cycle Output rise and fall time 6 MHz ≤ Fin ≤10 MHz 18 MHz ≤ Fin ≤ 30 MHz 325 pS (max) -1.25% or –2.4% 45/55% (worst case) 5ns (maximum) Simplified Block Diagram 3.3V X1 ASM3P2180A X2 Spread spectrum output (EMI suppressed) Alliance Semiconductor 2595, Augustine Drive • Santa Clara • CA 95054 • Tel 408 855 4900 • Fax 408 855 4999 • www.alsc.com Notice: The information in this document is subject to change without notice. September 2004 ASM3P2180A rev 1.0 Pin Diagram CLKIN / X1 1 NC / X2 2 8 NC 7 FS1 ASM3P2180A GND 3 6 VDD SS% 4 5 CLKOUT Modulation Width Selection SS% Output 0 FIN ≥ FOUT ≥ FIN – 1.25% 1 FIN ≥ FOUT ≥ FIN – 2.4% Frequency Range Selection FS1 Modulation Rate 0 6 ≤ FIN ≤10 1 18 ≤ FIN ≤ 30 Pin Description Pin# Pin Name Type Description 1 CLKIN / X1 I 2 NC / X2 O 3 GND P Ground to entire chip. 4 SS% I Modulation width selection. When spread spectrum feature is turned on, this pin is used to select the amount of variation and peak EMI reduction that is desired on the output signal. Internal pull-up resistor. 5 CLKOUT O Output modulated frequency. Copy of the un-modulated input clock. 6 VDD P Power supply for the entire chip (3.3V). 7 FS1 I Frequency selection bit 1. This pin selects the frequency range of operation. (Refer to the Frequency Range Selection Table). This pin has an internal pull-up resistor. 8 NC - No connect. 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. Connection for an external crystal. If using an external reference, this pin must be left unconnected. Peak Reducing EMI Solution Notice: The information in this document is subject to change without notice. 2 of 7 September 2004 ASM3P2180A 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 Min Typ Max Unit GND – 0.3 - 0.8 V 2.0 - VDD + 0.3 V - - -27 µA VIL Input low voltage VIH IIH Input high voltage Input low current (pull-up resistors on inputs SS%, FS1) Input high current - - 18 µA IXOL XOUT output low current (@ 0.4V, VDD = 3.3V) - 3 - mA IXOH XOUT output high current (@2.5V, VDD = 3.3V) - 4 - mA VOL Output low voltage (VDD = 3.3V, IOL = 4mA) - - 0.4 V VOH Output high voltage (VDD = 3.3V, IOH = 4mA) Dynamic supply current normal mode (3.3V and 10pF loading) Static supply current standby mode 2.5 - - V 8 21 35 mA - 0.8 - µA Operating voltage Power up time (first locked clock cycle after power up) Clock output impedance 2.8 3.3 3.7 V - 0.18 - mS - 50 - Ω IIL ICC IDD VDD tON ZOUT AC Electrical Characteristics Symbol Parameter Min Typ Max Unit CLKIN Input frequency 6 - 30 MHz CLKOUT Output frequency 6 - 30 MHz tLH* Output rise time (measured at 0.8V to 2.0V) 1.2 1.3 1.4 nS tHL* Output fall time (measured at 2.0V to 0.8V) 0.8 0.9 1.0 nS tJC Jitter (cycle to cycle) - - 325 pS 45 50 55 % tD Output duty cycle *tLH and tHL are measured into a capacitive load of 15pF Peak Reducing EMI Solution Notice: The information in this document is subject to change without notice. 3 of 7 September 2004 ASM3P2180A rev 1.0 Package Information: 8-Pin SOIC Package H E D A2 A C A1 D θ e L B Symbol Dimensions in inches 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 0° 8° 0° 8° Peak Reducing EMI Solution Notice: The information in this document is subject to change without notice. 4 of 7 September 2004 ASM3P2180A rev 1.0 8-Pin TSSOP Package H E D A2 A C θ e A1 L B Symbol Dimensions in inches Min Max Dimensions in millimeters Min Max 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 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° Peak Reducing EMI Solution Notice: The information in this document is subject to change without notice. 5 of 7 September 2004 ASM3P2180A rev 1.0 Ordering Codes Quantity per reel Ordering Number Marking Package Type ASM3P2180A-08ST ASM3P2180A 8-pin SOIC, tube ASM3P2180A-08SR ASM3P2180A 8-pin SOIC, tape and reel ASM3P2180A-08TT ASM3P2180A 8-pin TSSOP, tube ASM3P2180A-08TR ASM3P2180A 8-pin TSSOP, tape and reel Temperature 0° C to 70°C 2500 0° C to 70°C 0° C to 70°C 2500 0° C to 70°C Ordering Information A S M 3 P 2 1 8 0 A - 0 8 S T 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 PIN COUNT PART NUMBER X = Automotive I = Industrial P or n/c = Commercial 1 – reserved 6 – power management 2 - Non PLL based 7 – power management 3 – EMI Reduction 8 – power management 4 – DDR support products 9 – Hi performance 5 – STD Zero Delay Buffer 0 - reserved Alliance Semiconductor Mixed Signal Product Licensed under US patent Nos 5,488,627 and 5,631,920. Peak Reducing EMI Solution Notice: The information in this document is subject to change without notice. 6 of 7 September 2004 ASM3P2180A 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 Part Number: ASM3P2180A Document Version: v1.0 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. Peak Reducing EMI Solution Notice: The information in this document is subject to change without notice. 7 of 7