IDT5V50009

DATASHEET SPREAD SPECTRUM CLOCK GENERATOR Description The IDT5V50009 generates a low EMI output clock and a reference clock from a clock or crystal input. The part is designed to lower EMI through the application of spreading a clock. Using IDT’s proprietary mix of analog and digital Phase-Locked Loop (PLL) technology, the device spreads the frequency spectrum of the output, reducing the frequency amplitude peaks by several dB depending on spread range. The IDT5V50009 offers a range of down spread from a high speed clock or crystal input. The IDT5V50009 generates one modulated (SSCLK) and unmodulated (REFCLK) clock. The modulated clock is controlled by the select pin, and the unmodulated clock has the same frequency as the input clock or crystal. IDT5V50009 Features • • • • • • • • Packaged in 8-pin SOIC Available in Pb (lead) free package Input frequency range 20- 40 MHz Provides modulated and unmodulated clocks Accepts a clock or crystal input Provides down spread modulation Provides power down function Reduce electromagnetic interference (EMI) by 8-16 db • Operating voltage of 3.3 V • Advanced, low-power CMOS process Block Diagram VDD PD S0 PLL Clock Synthesis and Spread Spectrum Circuitry REFCLK X1/CLK Clock Buffer/ Crystal Ocsillator X2 External caps required for with crystal for accurate tuning of the clock SSCLK GND IDT™ SPREAD SPECTRUM CLOCK GENERATOR 1 IDT5V50009 REV C 040609 IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR SSCG Pin Assignment X1/ICLK GND S0 SSCLK 1 2 3 4 8 7 6 5 X2 VDD PD REFCLK Spread Percentage Select Table S0 0 1 Spread Direction Down Down Spread Percentage (%) -1.25 -1.75 0 = connect to GND 8 p i n ( 1 5 0 mi l ) S O I C 1 = connect directly to VDD * Default has internal pull up resistor to VDD Pin Descriptions Pin Number Pin Name Pin Type Pin Description 1 2 3 4 5 6 7 8 X1/ICLK GND S0 SSCLK REFCLK PD VDD X2 Input Power Input Output Output Input Power Input Connect to a 20 to 40 MHz crystal or clock. Connect to ground. Select spread percentage per table above. Weak Internal pull-up. Spread spectrum clock output per table above. Weak Internal Pull down CMOS level clock output matches the nominal frequency of the input crystal or clock. Weak Internal Pull down Power down tri-state. This pin powers down entire chip and tri-state the outputs when low. Weak Internal pull-up. Connect to 3.3 V. Connect to a 20 to 40 MHz crystal or leave unconnected. IDT™ SPREAD SPECTRUM CLOCK GENERATOR 2 IDT5V50009 REV C 040609 IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR SSCG External Components The IDT5V50009 requires a minimum number of external components for proper operation. Crystal Information The crystal used should be a fundamental mode (do not use third overtone), parallel resonant. Crystal capacitors should be connected from pins X1 to ground and X2 to ground to optimize the initial accuracy. The value of these capacitors is given by the following equation: Crystal caps (pF) = (CL - 6) x 2 In the equation, CL is the crystal load capacitance. So, for a crystal with a 16 pF load capacitance, two 20 pF [(16-6) x 2] capacitors should be used. Decoupling Capacitor A decoupling capacitor of 0.01µF must be connected between VDD and GND, as close to these pins as possible. For optimum device performance, the decoupling capacitor should be mounted on the component side of the PCB. Avoid the use of vias in the decoupling circuit. Series Termination Resistor When the PCB trace between the clock output and the load is over 1 inch, series termination should be used. To series terminate a 50Ω trace (a commonly used trace impedance) place a 33Ω resistor in series with the clock line, as close to the clock output pin as possible. The nominal impedance of the clock output is 20Ω . Spread Spectrum Profile The IDT5V50009 low EMI clock generator uses an optimized frequency slew rate algorithm to facilitate down stream tracking of zero delay buffers and other PLL devices. The frequency modulation amplitude is constant with variations of the input frequency. PCB Layout Recommendations For optimum device performance and lowest output phase noise, the following guidelines should be observed. 1) The 0.01µF decoupling capacitor should be mounted on the component side of the board as close to the VDD pin as possible. No vias should be used between the decoupling capacitor and VDD pin. The PCB trace to VDD pin should be kept as short as possible, as should the PCB trace to the ground via. 2) To minimize EMI, the 33Ω series termination resistor (if needed) should be placed close to the clock output. 3) An optimum layout is one with all components on the same side of the board, minimizing vias through other signal layers. Other signal traces should be routed away from the IDT5V50009. This includes signal traces just underneath the device, or on layers adjacent to the ground plane layer used by the device. Modulation R ate Frequency Time IDT™ SPREAD SPECTRUM CLOCK GENERATOR 3 IDT5V50009 REV C 040609 IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR SSCG Absolute Maximum Ratings Stresses above the ratings listed below can cause permanent damage to the IDT5V50009. These ratings, which are standard values for IDT commercially rated parts, are stress ratings only. Functional operation of the device at these or any other conditions above those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods can affect product reliability. Electrical parameters are guaranteed only over the recommended operating temperature range. Item Supply Voltage, VDD All Inputs and Outputs Ambient Operating Temperature Storage Temperature Junction Temperature Soldering Temperature 7V Rating -0.5 V to VDD+0.5 V 0 to +70° C -65 to +150° C 125° C 260° C Recommended Operation Conditions Parameter Ambient Operating Temperature Power Supply Voltage (measured in respect to GND) Min. 0 +2.97 Typ. Max. +70 3.63 Units °C V DC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V +10%, Ambient Temperature 0 to +70° C Parameter Power Supply Range Input High Voltage Input Low Voltage Output High Voltage Output Low Voltage Power Supply Current. Operating Power Supply Current Stand by Input Capacitance Clock Output Impedance Internal Pull-up Resistor Internal Pull-down Resistor Symbol VDD VIH VIL VOH VOL IDD IDD CIN RPU RPd Conditions S0 Input S0 Input IOH =-12 ma, SSCLK and REFCLK IOL =12ma, SSCLK FIN =32 MHz, no load PD = GND Min. 2.97 2.0 0.0 2.4 Typ. 3.3 0.0 Max. 3.63 0.8 Units V V V V 0.4 19.0 150 5 20 23.0 250 V mA µA pF ohms kΩ kΩ So, PD SSCLK 550 240 IDT™ SPREAD SPECTRUM CLOCK GENERATOR 4 IDT5V50009 REV C 040609 IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR SSCG AC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V +10%, Ambient Temperature 0 to +70° C Parameter Input Clock Frequency Output Clock Frequency Clock Rise Time Clock Fall Time Output Clock Duty Cycle Cycle-to-Cycle Jitter Symbol Conditions Min. 20 20 Typ. Max. Units 40 40 MHz MHz ns ns 55 350 % ps trise1 tfall1 SSCLK and REFCLK, 0.8 V to 2.0 V SSCLK and REFCLK, 0.8 V to 2.0 V SSCLK and REFCLK @1.65V SSCLK, Fin=27MHz, Fout=27MHz REFCLK, Fin=27MHz, Fout=27MHz Input/512 39 45 0.75 0.75 50 250 Cycle-to-Cycle Jitter 275 375 ps Modulation rate EMI Peak Frequency Reduction 78 8 to 16 kHz dB Thermal Characteristics Parameter Thermal Resistance Junction to Ambient Symbol θJA θJA θJA θJC Conditions Still air 1 m/s air flow 3 m/s air flow Min. Typ. 110 100 80 35 Max. Units ° C/W ° C/W ° C/W ° C/W Thermal Resistance Junction to Case IDT™ SPREAD SPECTRUM CLOCK GENERATOR 5 IDT5V50009 REV C 040609 IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR SSCG Marking Diagram (Pb free) 8 5 IDT5V50 009DCG ZYYWW$ 1 Notes: 1. “Z” is the device step (1 to 2 characters). 2. YYWW is the last two digits of the year and week that the part was assembled. 3. “$” is the assembly mark code. 4. “G” after the two-letter package code designates RoHS compliant package. 5. Bottom marking: country of origin if not USA. 4 IDT™ SPREAD SPECTRUM CLOCK GENERATOR 6 IDT5V50009 REV C 040609 IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR SSCG Package Outline and Package Dimensions (8 pin SOIC, 150 Mil. Narrow Body) Package dimensions are kept current with JEDEC Publication No. 95 Millimeters Min Max Inches Min Max Symbol Index Area EH Pin 1 D h x 45 0 A A1 B C D E e H h L a 1.35 1.75 1.10 0.25 0.33 0.51 0.19 0.25 4.80 5.00 3.80 4.00 1.27 Basic 5.80 6.20 0.25 0.50 0.40 1.27 0° 8° 0.0532 0.0688 0.0040 0.0098 0.013 0.020 0.0075 0.0098 .1890 .1968 0.1497 0.1574 0.050 Basic 0.2284 0.2440 0.010 0.020 0.016 0.050 0° 8° A Q e b c Ordering Information Part / Order Number 5V50009DCG 5V50009DCG8 Marking See page 6 Shipping Packaging Tubes Tape and Reel Package 8-pin SOIC 8-pin SOIC Temperature 0 to +70° C 0 to +70° C Parts that are ordered with a “G” after the two-letter package code are the Pb-Free configuration and are RoHS compliant. While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes no responsibility for either its use or for the infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal commercial applications. Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are not recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT does not authorize or warrant any IDT product for use in life support devices or critical medical instruments. IDT™ SPREAD SPECTRUM CLOCK GENERATOR 7 IDT5V50009 REV C 040609 IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR SSCG Innovate with IDT and accelerate your future networks. Contact: www.IDT.com For Sales 800-345-7015 408-284-8200 Fax: 408-284-2775 For Tech Support www.idt.com/go/clockhelp Corporate Headquarters Integrated Device Technology, Inc. www.idt.com © 2006 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are trademarks of Integrated Device Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or registered trademarks used to identify products or services of their respective owners. Printed in USA