DATASHEET TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER ICS345 Description Features The ICS345 field programmable clock synthesizer generates up to nine high-quality, high-frequency clock outputs including multiple reference clocks from a low-frequency crystal or clock input. It is designed to replace crystals and crystal oscillators in most electronic systems. • • • • • • • • • • • • Using IDT’s VersaClockTM software to configure PLLs and outputs, the ICS345 contains a One-Time Programmable (OTP) ROM to allow field programmability. Programming features include eight selectable configuration registers, up to two sets of four low-skew outputs, and optional Spread Spectrum outputs. Using Phase-Locked Loop (PLL) techniques, the device runs from a standard fundamental mode, inexpensive crystal, or clock. It can replace multiple crystals and oscillators, saving board space and cost. • The ICS345 is also available in factory programmed custom versions for high-volume applications. Packaged as 20-pin SSOP (QSOP) Spread spectrum capability Eight addressable registers Replaces multiple crystals and oscillators Output frequencies up to 200 MHz at 3.3 V Input crystal frequency of 5 to 27 MHz Input clock frequency of 2 to 50 MHz Up to nine reference outputs Up to two sets of four low-skew outputs Operating voltages of 3.3 V Advanced, low-power CMOS process For one output clock, use the ICS341. For two output clocks, see the ICS342. For three output clocks, see the ICS343. For more than three outputs, see the ICS345 or ICS348. Available in Pb (lead) free packaging Block Diagram VDD S 2:S 0 3 OTP ROM w ith P LL V alues C rystal or clock input 3 P LL1 with S pread S pectrum C LK 1 C LK 2 C LK 3 D ivide Logic and O utput E nable C ontrol P LL2 P LL3 X 1/IC LK C LK 4 C LK 5 C LK 6 C LK 7 C LK 8 C rystal O scillator C LK 9 X2 E xternal capacitors are required w ith a crystal input. GND 2 PD TS IDT™ / ICS™ TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER 1 ICS345 REV K 110207 ICS345 TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER EPROM CLOCK SYNTHESIZER Pin Assignment X1/ICLK 1 20 X2 S0 2 19 VDD S1 3 18 PDTS CLK9 4 17 S2 VDD 5 16 VDD GND 6 15 GND CLK1 7 14 CLK5 CLK2 8 13 CLK6 CLK3 9 12 CLK7 CLK4 10 11 CLK8 20-pin (150 mil) SSOP (QSOP) Pin Descriptions Pin Number Pin Name Pin Type 1 X1/ICLK XI 2 S0 Input 3 S1 Input 4 CLK9 Output Pin Description Crystal input. Connect this pin to a crystal or external input clock. Select pin 0. Internal pull-up resistor. Select pin 1. Internal pull-up resistor. 5 VDD Power Output clock 9. Weak internal pull-down when tri-state. Connect to +3.3 V. 6 GND Power Connect to ground. 7 CLK1 Output Output clock 1. Weak internal pull-down when tri-state. 8 CLK2 Output Output clock 2. Weak internal pull-down when tri-state. 9 CLK3 Output Output clock 3. Weak internal pull-down when tri-state. 10 CLK4 Output Output clock 4. Weak internal pull-down when tri-state. 11 CLK8 Output Output clock 8. Weak internal pull-down when tri-state. 12 CLK7 Output Output clock 7. Weak internal pull-down when tri-state. 13 CLK6 Output Output clock 6. Weak internal pull-down when tri-state. 14 CLK5 Output Output clock 5. Weak internal pull-down when tri-state. 15 GND Power 16 VDD Power Connect to ground. Connect to +3.3 V. 17 S2 Input Select pin 2. Internal pull-up resisitor. 18 PDTS Input 19 VDD Power 20 X2 XO Power-down tri-state. Powers down entire chip and tri-states clock outputs when low. Internal pull-up resisitor. Connect to +3.3 V. Crystal Output. Connect this pin to a crystal. Float for clock input. IDT™ / ICS™ TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER 2 ICS345 REV K 110207 ICS345 TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER EPROM CLOCK SYNTHESIZER External Components they should be separated and away from other traces. Series Termination Resistor 3) To minimize EMI, the 33Ω series termination resistor (if needed) should be placed close to the clock output. Clock output traces over one inch should use series termination. 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. Decoupling Capacitors 4) An optimum layout is one with all components on the same side of the board, minimizing vias through other signal layers. ICS345 Configuration Capabilities As with any high-performance mixed-signal IC, the ICS345 must be isolated from system power supply noise to perform optimally. The architecture of the ICS345 allows the user to easily configure the device to a wide range of output frequencies, for a given input reference frequency. Decoupling capacitors of 0.01µF must be connected between each VDD and the PCB ground plane. The frequency multiplier PLL provides a high degree of precision. The M/N values (the multiplier/divide values available to generate the target VCO frequency) can be set within the range of M = 1 to 2048 and N = 1 to 1024. Crystal Load Capacitors The device crystal connections should include pads for small capacitors from X1 to ground and from X2 to ground. These capacitors are used to adjust the stray capacitance of the board to match the nominally required crystal load capacitance. Because load capacitance can only be increased in this trimming process, it is important to keep stray capacitance to a minimum by using very short PCB traces (and no vias) between the crystal and device. Crystal capacitors must be connected from each of the pins X1 and X2 to ground. The value (in pF) of these crystal caps should equal (CL -6 pF)*2. In this equation, CL= crystal load capacitance in pF. Example: For a crystal with a 16 pF load capacitance, each crystal capacitor would be 20 pF [(16-6) x 2 = 20]. PCB Layout Recommendations For optimum device performance and lowest output phase noise, the following guidelines should be observed. 1) Each 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 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. The ICS345 also provides separate output divide values, from 2 through 20, to allow the two output clock banks to support widely differing frequency values from the same PLL. Each output frequency can be represented as: OutputFreq = REFFreq -------------------------------------OutputDivide ⋅ M ----N IDT VersaClock Software IDT applies years of PLL optimization experience into a user friendly software that accepts the user’s target reference clock and output frequencies and generates the lowest jitter, lowest power configuration, with only a press of a button. The user does not need to have prior PLL experience or determine the optimal VCO frequency to support multiple output frequencies. VersaClock software quickly evaluates accessible VCO frequencies with available output divide values and provides an easy to understand, bar code rating for the target output frequencies. The user may evaluate output accuracy, performance trade-off scenarios in seconds. 2) The external crystal should be mounted just next to the device with short traces. The X1 and X2 traces should not be routed next to each other with minimum spaces, instead IDT™ / ICS™ TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER 3 ICS345 REV K 110207 ICS345 TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER Spread Spectrum Modulation The ICS345 utilizes frequency modulation (FM) to distribute energy over a range of frequencies. By modulating the output clock frequencies, the device effectively lowers energy across a broader range of frequencies; thus, lowering a system’s electromagnetic interference (EMI). The modulation rate is the time from transitioning from a minimum frequency to a maximum frequency and then back to the minimum. Spread Spectrum Modulation can be applied as either “center spread” or “down spread”. During center spread modulation, the deviation from the target frequency is equal in the positive and negative directions. The effective average frequency is equal to the target frequency. In applications where the clock is driving a component with a maximum frequency rating, down spread should be applied. In this case, the maximum frequency, including modulation, is the target frequency. The effective average frequency is less than the target frequency. EPROM CLOCK SYNTHESIZER The ICS345 operates in both center spread and down spread modes. For center spread, the frequency can be modulated between ±0.125% to ±2.0%. For down spread, the frequency can be modulated between -0.25% to -4.0%. Both output frequency banks will utilize identical spread spectrum percentage deviations and modulation rates, if a common VCO frequency can be identified. Spread Spectrum Modulation Rate The spread spectrum modulation frequency applied to the output clock frequency may occur at a variety of rates. For applications requiring the driving of “down-circuit” PLLs, Zero Delay Buffers, or those adhering to PCI standards, the spread spectrum modulation rate should be set to 30-33 kHz. For other applications, a 120 kHz modulation option is available. Absolute Maximum Ratings Stresses above the ratings listed below can cause permanent damage to the ICS345. 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. Parameter Condition Supply Voltage, VDD Referenced to GND Inputs Referenced to GND Clock Outputs Referenced to GND Storage Temperature Soldering Temperature Max 10 seconds Junction Temperature IDT™ / ICS™ TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER 4 Min. Typ. Max. Units 7 V -0.5 VDD+0.5 V -0.5 VDD+0.5 V -65 150 °C 260 °C 125 °C ICS345 REV K 110207 ICS345 TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER EPROM CLOCK SYNTHESIZER Recommended Operation Conditions Parameter Min. Typ. Max. Units Ambient Operating Temperature (ICS345RP) 0 +70 °C Ambient Operating Temperature (ICS345RIP) -40 +85 °C +3.45 V 4 ms Power Supply Voltage (measured in respect to GND) +3.15 +3.3 Power Supply Ramp Time DC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V ±5%, Ambient Temperature -40 to +85° C Parameter Symbol Operating Voltage VDD Operating Supply Current Input High Voltage IDD Conditions Min. Typ. 3.15 Max. Units 3.45 V Configuration Dependent See VersaClockTM Estimates mA Nine 33.3333 MHz outs, PDTS = 1, no load, Note 1 23 mA 20 µA V Input High Voltage VIH PDTS = 0, no load, Note 1 S2:S0 Input Low Voltage VIL S2:S0 Input High Voltage, PDTS VIH Input Low Voltage, PDTS VIL Input High Voltage VIH ICLK Input Low Voltage VIL ICLK Output High Voltage (CMOS High) VOH IOH = -4 mA VDD-0.4 V Output High Voltage VOH IOH = -12 mA 2.4 V Output Low Voltage VOL IOL = 12 mA Short Circuit Current IOS ±70 mA Nominal Output Impedance ZO 20 Ω 2 0.4 VDD-0.5 V V 0.4 VDD/2+1 V V VDD/2-1 0.4 V V Internal Pull-up Resistor RPUS S2:S0, PDTS 250 kΩ Internal Pull-down Resistor RPD CLK outputs 525 kΩ Input Capacitance CIN Inputs 4 pF Note 1: Example with 25 MHz crystal input with nine outputs of 33.3 MHz, no load, and VDD = 3.3 V. IDT™ / ICS™ TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER 5 ICS345 REV K 110207 ICS345 TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER EPROM CLOCK SYNTHESIZER AC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V ±5%, Ambient Temperature -40 to +85° C Parameter Symbol Input Frequency FIN Output Frequency Conditions Min. Typ. Max. Units Fundamental crystal 5 27 MHz Input clock 2 50 MHz VDD=3.3 V 0.25 200 MHz Output Rise Time tOR 20% to 80%, Note 1 1 ns Output Fall Time tOF 80% to 20%, Note 1 1 ns Duty Cycle Note 2 Output Frequency Synthesis Error (Note 4) Configuration Dependent 0 Power-up Time PLL lock-time from power-up, Note 3 4 10 ms PDTS goes high until stable CLK output, Spread Spectrum Off, Note 3 0.2 2 ms PDTS goes high until stable CLK output, Spread Spectrum On, Note 3 4 7 ms Configuration Dependent 50 ps Deviation from Mean. Configuration Dependent +200 ps One Sigma Clock Period Jitter Maximum Absolute Jitter tja Pin-to-Pin Skew 40 Low Skew Outputs 49-51 60 % ppm -250 250 ps Note 1: Measured with 15 pF load. Note 2: Duty Cycle is configuration dependent. Most configurations are min 45% / max 55% Note 3: IDT test mode output occurs for first 170 clock cycles on CLK7 for each PLL powered up. PDTS transition high on select address change. Note 4: The actual ppm error will be displayed in the VersaClock software when the programming file is generated for the customer’s specific configuration. In general, zero ppm error can be achieved, but please note that the device cannot improve upon the error of the input reference clock. For example, if the input crystal has 25 ppm error, then the outputs will also have 25 ppm error. Thermal Characteristics Parameter Thermal Resistance Junction to Ambient Thermal Resistance Junction to Case Symbol Conditions Min. Typ. Max. Units θ JA Still air 135 ° C/W θ JA 1 m/s air flow 93 ° C/W θ JA 3 m/s air flow 78 ° C/W 60 ° C/W θ JC IDT™ / ICS™ TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER 6 ICS345 REV K 110207 ICS345 TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER EPROM CLOCK SYNTHESIZER Package Outline and Package Dimensions (20-pin SSOP, 150 Mil. Wide Body) Package dimensions are kept current with JEDEC Publication No. 95 Millimeters Inches* 20 Symbol E1 A A1 A2 b c D E E1 e L α aaa E INDEX AREA 1 2 D A A2 Min Max 1.35 1.75 0.10 0.25 -1.50 0.20 0.30 0.18 0.25 8.55 8.75 5.80 6.20 3.80 4.00 .635 Basic 0.40 1.27 0° 8° -0.10 Min Max 0.053 0.069 0.004 0.010 -0.059 0.008 0.012 0.007 0.010 0.337 0.344 0.228 0.244 0.150 0.157 .025 Basic 0.016 0.050 0° 8° -0.004 *For reference only. Controlling dimensions in mm. A1 c -Ce b SEATING PLANE L aaa C IDT™ / ICS™ TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER 7 ICS345 REV K 110207 ICS345 TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER EPROM CLOCK SYNTHESIZER Ordering Information Part / Order Number Marking Shipping Packaging Package Temperature ICS345RP ICS345RP Tubes 20-pin SSOP 0 to +70° C ICS345RPT ICS345RP Tape and Reel 20-pin SSOP 0 to +70° C ICS345RIP ICS345RIP Tubes 20-pin SSOP -40 to +85° C ICS345RIPT ICS345RIP Tape and Reel 20-pin SSOP -40 to +85° C ICS345RPLF ICS345RPLF Tubes 20-pin SSOP 0 to +70° C ICS345RPLFT ICS345RPLF Tape and Reel 20-pin SSOP 0 to +70° C ICS345RIPLF ICS345RIPLF Tubes 20-pin SSOP -40 to +85° C ICS345RIPLFT ICS345RIPLF Tape and Reel 20-pin SSOP -40 to +85° C ICS345R-XX ICS345R-XX Tubes 20-pin SSOP 0 to +70° C ICS345R-XXT ICS345R-XX Tape and Reel 20-pin SSOP 0 to +70° C ICS345RI-XX ICS345RI-XX Tubes 20-pin SSOP -40 to +85° C ICS345RI-XXT ICS345RI-XX Tape and Reel 20-pin SSOP -40 to +85° C ICS345R-XXLF 345R-XXLF Tubes 20-pin SSOP 0 to +70° C ICS345R-XXLFT 345R-XXLF Tape and Reel 20-pin SSOP 0 to +70° C ICS345RI-XXLF 345RI-XXLF Tubes 20-pin SSOP -40 to +85° C ICS345RI-XXLFT 345RI-XXLF Tape and Reel 20-pin SSOP -40 to +85° C Parts that are ordered with a “LF” suffix to the part number are the Pb-Free configuration and are RoHS compliant. The ICS345R-XX, ICS345R-XXLF, ICS345RI-XX, and ICS345RI-XXLF are factory programmed versions of the ICS345RP, ICS345RPLF, ICS345RIP, and ICS345RIPLF. A unique “-XX” suffix is assigned by the factory for each custom configuration, and a separate data sheet is kept on file. For more information on custom part numbers programmed at the factory, please contact your local IDT sales and marketing representative. While the information presented herein has been checked for both accuracy and reliability, 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™ / ICS™ TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER 8 ICS345 REV K 110207 ICS345 TRIPLE PLL FIELD PROGRAMMABLE SS VERSACLOCK SYNTHESIZER EPROM CLOCK SYNTHESIZER 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