IDT5V50009DCG

DATASHEET IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR Description Features 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. • • • • • • • • 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 X1/CLK Clock Buffer/ Crystal Ocsillator REFCLK SSCLK X2 External caps required for with crystal for accurate tuning of the clock IDT™ SPREAD SPECTRUM CLOCK GENERATOR GND 1 IDT5V50009 REV C 040609 IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR SSCG Pin Assignment Spread Percentage Select Table X1/ICLK 1 8 X2 GND 2 7 VDD S0 3 6 PD SSCLK 4 5 REFCLK S0 Spread Direction Spread Percentage (%) 0 1 Down Down -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 X1/ICLK Input Connect to a 20 to 40 MHz crystal or clock. 2 GND Power Connect to ground. 3 S0 Input Select spread percentage per table above. Weak Internal pull-up. 4 SSCLK Output Spread spectrum clock output per table above. Weak Internal Pull down 5 REFCLK Output CMOS level clock output matches the nominal frequency of the input crystal or clock. Weak Internal Pull down 6 PD Input Power down tri-state. This pin powers down entire chip and tri-state the outputs when low. Weak Internal pull-up. 7 VDD Power Connect to 3.3 V. 8 X2 Input 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 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: The IDT5V50009 requires a minimum number of external components for proper operation. 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. 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. 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. Modulation Rate Frequency 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. Time 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. 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 Rating Supply Voltage, VDD 7V All Inputs and Outputs -0.5 V to VDD+0.5 V Ambient Operating Temperature 0 to +70° C Storage Temperature -65 to +150° C Junction Temperature 125° C Soldering Temperature 260° C Recommended Operation Conditions Parameter Min. Max. Units 0 +70 °C +2.97 3.63 V Ambient Operating Temperature Power Supply Voltage (measured in respect to GND) Typ. DC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V +10%, Ambient Temperature 0 to +70° C Parameter Symbol Conditions Min. Typ. Max. Units 2.97 3.3 3.63 V Power Supply Range VDD Input High Voltage VIH S0 Input 2.0 Input Low Voltage VIL S0 Input 0.0 Output High Voltage VOH IOH =-12 ma, SSCLK and REFCLK 2.4 Output Low Voltage VOL IOL =12ma, SSCLK Power Supply Current. Operating IDD FIN =32 MHz, no load Power Supply Current Stand by IDD PD = GND Input Capacitance CIN Clock Output Impedance V 0.0 0.8 V V 0.4 V 19.0 23.0 mA 150 250 µA 5 pF 20 ohms Internal Pull-up Resistor RPU So, PD 550 kΩ Internal Pull-down Resistor RPd SSCLK 240 kΩ 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 Symbol Conditions Min. Typ. Max. Units Input Clock Frequency 20 40 MHz Output Clock Frequency 20 40 MHz Clock Rise Time trise1 SSCLK and REFCLK, 0.8 V to 2.0 V 0.75 ns Clock Fall Time tfall1 SSCLK and REFCLK, 0.8 V to 2.0 V 0.75 ns Output Clock Duty Cycle SSCLK and REFCLK @1.65V Cycle-to-Cycle Jitter 45 50 55 % SSCLK, Fin=27MHz, Fout=27MHz 250 350 ps Cycle-to-Cycle Jitter REFCLK, Fin=27MHz, Fout=27MHz 275 375 ps Modulation rate Input/512 78 kHz 39 EMI Peak Frequency Reduction 8 to 16 dB Thermal Characteristics Parameter Thermal Resistance Junction to Ambient Thermal Resistance Junction to Case IDT™ SPREAD SPECTRUM CLOCK GENERATOR Symbol Conditions Min. Typ. Max. Units θJA Still air 110 ° C/W θJA 1 m/s air flow 100 ° C/W θJA 3 m/s air flow 80 ° C/W 35 ° C/W θJC 5 IDT5V50009 REV C 040609 IDT5V50009 SPREAD SPECTRUM CLOCK GENERATOR SSCG Marking Diagram (Pb free) 8 5 IDT5V50 009DCG ZYYWW$ 1 4 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. 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 Symbol Millimeters Min Max Inches Min Max 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° Index Area E H Pin 1 h x 45 0 D A Q c e b Ordering Information Part / Order Number Marking Shipping Packaging Package Temperature 5V50009DCG See page 6 Tubes 8-pin SOIC 0 to +70° C Tape and Reel 8-pin SOIC 0 to +70° C 5V50009DCG8 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 For Tech Support 800-345-7015 408-284-8200 Fax: 408-284-2775 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