DATASHEET MK74CG117B 16 OUTPUT LOW SKEW CLOCK GENERATOR Description Features The MK74CG117B is a monolithic CMOS high speed, low-skew clock driver that includes an on-chip PLL. Ideal for communications and other systems that require a large number of high-speed clocks, the unique combination of PLL and 16 low-skew outputs can eliminate oscillators and low skew buffers from systems. * 48-pin SSOP (300 mil) package * On-chip PLL generates output clocks up to 100 MHz from a simple crystal or clock input * 16 low-skew outputs * Output skew less than 250 ps on rising edges * Ability to configure as The device has a number of built in multipliers, making it possible to run from one inexpensive, low frequency crystal, and produce high frequency clock outputs. Another selection allows the chip to run as a divider, dividing the input clock by two (or 4 using the mode select). -16 clocks at full frequency -12 at full and 4 at half frequency -8 at full and 8 at half frequency The device also has a buffered reference output, allowing multiple devices to be easily driven from one clock source. * Tri-state mode for Output Enable function * 3.3 V 5% supply voltage * Industrial temperature version available Block Diagram VDD 9 S2:0 M1:0 Crystal or clock input 3 Clock Synthesis and Mode Select Circuitry 2 Clock 1 Clock 2 Clock 16 X1/ICLK Crystal Ocsillator REF X2 The crystal requires external capacitors for accurate tuning of the clock IDTTM 16 OUTPUT LOW SKEW CLOCK GENERATOR 10 GND 1 MK74CG117B REV D 073108 MK74CG117B 16 OUTPUT LOW SKEW CLOCK GENERATOR CLOCK SYNTHESIZER Pin Assignment VDD 1 48 S0 X1/ICLK 2 47 CLK16 X2 3 46 VDD NC 4 45 VDD NC 5 44 NC GND 6 43 CLK15 GND 7 42 CLK14 S2 8 41 GND REF 9 40 GND S1 10 39 M1 GND 11 38 CLK13 GND 12 37 CLK12 CLK1 13 36 VDD CLK2 14 35 VDD VDD 15 34 M0 VDD 16 33 CLK11 CLK3 17 32 CLK10 CLK4 18 31 CLK9 GND 19 30 VDD GND 20 29 NC NC 21 28 GND CLK5 22 27 GND CLK6 23 26 CLK8 VDD 24 25 CLK7 48-pin (300 mil) SSOP IDTTM 16 OUTPUT LOW SKEW CLOCK GENERATOR 2 MK74CG117B REV D 073108 MK74CG117B 16 OUTPUT LOW SKEW CLOCK GENERATOR CLOCK SYNTHESIZER Pin Descriptions Pin Number Pin Name Pin Type 1, 15, 16, 24, 30, 35, 36, 45, 46 VDD Power 2 X1/ICLK XI Connect to a crystal input or clock. 3 X2 XO Connect to a crystal, or leave unconnected for clock input. 4, 5, 21, 29, 44 NC -- No connect. Nothing is connected to these pins. 6, 7, 11, 12, 19, 20, 27, 28, 40, 41 GND Power Connect to ground. 8, 10, 48 S2, S1, S0 Input Multiplier select pins. See table 2. 9 REF Output Crystal oscillator buffered reference clock output. 13, 14, 17, 18 CLK1 - 4 Output Clock 1 - 4. Can be either full or half speed per Table 1. 22, 23, 25, 26, 31, 32, 33, 37 CLK5 - 12 Output Clock outputs 5 - 12. At full (1x) speed unless tristated per Table 1. 34, 39 M0, M1 Input Mode Select pins. Selects tri-state or speed of outputs per Table 1. 38, 42, 43, 47 CLK13 - 16 Output External Components Connect to VDD. Clock 13 - 16. Can be either full or half speed per Table 1. 2) To minimize EMI, place the 33 series-termination resistor (if needed) close to the clock output. The MK74CG117B requires a minimum number of external components for proper operation. 3) An optimum layout is one with all components on the same side of the board, thus minimizing vias through other signal layers. Other signal traces should be routed away from the MK74CG117B device. This includes signal traces located underneath the device, or on layers adjacent to the ground plane layer used by the device. Decoupling Capacitor A decoupling capacitor of 0.1F must be connected between each VDD and GND. Connect the capacitor as close to these pins as possible. For optimum device performance, mount the decoupling capacitor on the component side of the PCB. Avoid the use of vias in the decoupling circuit. Crystal Information The crystal used should be a fundamental mode (do not use third overtone), parallel resonant crystal. The oscillator has internal caps that provide the proper load for a crystal with CL = 18 pF. The value of these capacitors is given by the following equation: PCB Layout Recommendations For optimum device performance and lowest output phase noise, observe the following guidelines: Crystal caps (pF) = (CL - 18) x 2 1) Mount the 0.01F decoupling capacitor 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 the VDD pin and the PCB trace to the ground via should be kept as short as possible. IDTTM 16 OUTPUT LOW SKEW CLOCK GENERATOR Pin Description 3 MK74CG117B REV D 073108 MK74CG117B 16 OUTPUT LOW SKEW CLOCK GENERATOR CLOCK SYNTHESIZER Power Dissipation, Termination, and Operating Frequency Table 2. Multiplier Selections (Input and CLK Frequencies in MHz) As with all clock drivers, the power dissipated by the MK74CG117B is affected by the external loading on the output pins. This consists of the capacitance of the load that is being driven, as well as the PC board trace itself. Since this capacitance must be charged and discharged with each cycle of the output clock, as the frequency goes up. so does the power required. Operating below the specified maximum output clock frequency shown in Table 2 will keep the MK74CG117B power dissipation within acceptable limits. External series termination resistors must be used in series with each output. These resistors serve two purposes: The first is to match the source impedance to the line (PC board trace) that is being driven. This will minimize reflections that cause non-linear transitions on the output clock waveform. The output impedance of the MK74CG117B is approximately 20; assuming a 50 line, then a 33 resistor should be used at each output as shown in Figure 1. Mode at CLK(1x) at CLK/2(0.5x) 0 0 All outputs, including REF, tri-stated Z Z 0 1 12 @ 1x, 4 @ 0.5x CLK1-12 CLK13-16 Input Multiplier CLK Out Comments 0 0 0 33-50 0.5 16.5-25 0 0 0 1 1 1 1 0 1 1 0 0 1 1 1 0 1 0 1 0 1 20-50 16-40 10-50 8-40 8-30 8-25 8-20 1 1.25 2 2.5 3.333 4 5 20-50 20-50 20-100 20-100 26.7-100 32-100 40-90 Divider only; no PLL PLL PLL PLL PLL PLL PLL PLL Figure 1. External Termination MK74CG117 Output Table 1. Tri-state and Mode Select M1 M0 S2 S1 S0 33 ohm To load Max Output Freq. As speeds rise, the limiting factor in device operation becomes the power generated by having a large number of drivers in one package. Using the external termination resistors reduces the power dissipated within the device, allowing output frequencies up to 100 MHz. 83.3 MHz 0.8 1 0 8 @ 1x, 8 @ 0.5x CLK5-12 CLK1-4, 13-16 83.3 MHz 1.25 1 1 16 outputs @ 1x CLK1-16 None 100 MHz Note that the maximum operating frequency of the MK74CG117A is determined by the Mode selected from Table 1 and the Multiplier selected from Table 2. For output frequencies above 83.3 MHz, all 16 outputs must be at the same frequency (M1=M0=1). When operating with a combination of 1X and 0.5X outputs, the output frequency cannot exceed 83.3 MHz. IDTTM 16 OUTPUT LOW SKEW CLOCK GENERATOR 4 MK74CG117B REV D 073108 MK74CG117B 16 OUTPUT LOW SKEW CLOCK GENERATOR CLOCK SYNTHESIZER Absolute Maximum Ratings Stresses above the ratings listed below can cause permanent damage to the MK74CG117B. 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 (referenced to GND) 7V All Inputs and Outputs (referenced to GND) 0.5 V to VDD+0.5 V Ambient Operating Temperature -40 to +85 C Storage Temperature -65 to +150 C Junction Temperature 125 C Soldering Temperature 260 C Recommended Operation Conditions Parameter Min. Typ. Max. Units Ambient Operating Temperature -40 +85 C Power Supply Voltage (measured in respect to GND) +3.0 3.63 V Min. Typ. Max. Units 3.14 3.3 3.47 V DC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V 10%, Ambient Temperature -40 to +85 C Parameter Symbol Conditions Operating Voltage VDD Supply Current (at 50 MHz) IDD No load Input High Voltage, ICLK VIH pin 2 Input Low Voltage, ICLK VIL pin 2 Output High Voltage VOH IOH = -8 mA VDD-0.4 V Output High Voltage VOH IOH = -12 mA 2.0 V Output Low Voltage, 3.3 V VOL IOL = 12 mA Short Circuit Current Input Capacitance VDD-1 IDTTM 16 OUTPUT LOW SKEW CLOCK GENERATOR mA VDD/2 V VDD/2 1 0.4 Each output CIN 63 35 S0, S1, FRSEL pins 5 7 V V mA 6 MK74CG117B pF REV D 073108 MK74CG117B 16 OUTPUT LOW SKEW CLOCK GENERATOR CLOCK SYNTHESIZER AC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V 10%, Ambient Temperature 0 to +85 C, CL = 15 pF Parameter Symbol Conditions Min. Input Clock Frequency See table 2 Input Crystal Frequency Except when S2=S1=1 Output Clock Frequency (see tables 1, 2) M1=M0=1 Output Clock Duty Cycle At VDD/2 Output Clock Rising Edge Skew Typ. Max. Units 8 20 MHz 100 MHz 50 55 % VDD=3.3 V, Note 2 150 250 ps Absolute Clock Period Jitter, except REF VDD=3.3 V 300 ps Absolute Clock Period Jitter, REF VDD=3.3 V 500 ps 45 Output Clock Rise Time tR 0.8 to 2.0 V, Note 1 1.5 2 ns Output Clock Fall Time tF 2.0 V to 0.8 V, Note 1 1.5 2 ns 100 MHz output clock 240 pF 83.3 MHz output clock 320 pF Maximum Load per Total of 16 Outputs, with 33 termination, Note 3 Note 1: Based upon characterization data with a 33 series termination resistor and 15 pF capacitor to ground. Note 2: Between any two outputs with equal loading. Note 3: Additional load may be driven with the addition of an external heat sink. Contact IDT for details. Thermal Characteristics for 48-pin SSOP Parameter Thermal Resistance Junction to Ambient Thermal Resistance Junction to Case IDTTM 16 OUTPUT LOW SKEW CLOCK GENERATOR Symbol Conditions Min. Typ. Max. Units JA Still air 80 C/W JA 1 m/s air flow 67 C/W JA 3 m/s air flow 54 C/W 45 C/W JC 6 MK74CG117B REV D 073108 MK74CG117B 16 OUTPUT LOW SKEW CLOCK GENERATOR CLOCK SYNTHESIZER Package Outline and Package Dimensions (48-pin SSOP, 300 Mil. Body) Package dimensions are kept current with JEDEC Publication No. 95 48 Millimeters Symbol E1 INDEX AREA A A1 b c D E E1 e h L E 1 2 D Min Inches Max Min 2.41 2.80 0.20 0.40 0.20 0.34 0.13 0.25 15.75 16.00 10.03 10.68 7.40 7.60 0.635 BASIC 0.38 0.64 0.50 1.02 0 8 Max .095 .110 .008 .016 .008 .0135 .005 .010 .620 .630 .395 .420 .291 .299 0.025 BASIC .015 .025 .020 .040 0 8 A A2 A1 c - Ce b SEATING PLANE L aaa C Ordering Information Part / Order Number Marking Shipping Packaging Package Temperature MK74CG117BF MK74CG117BFT MK74CG117BFLF MK74CG117BFLFT MK74CG117BFI MK74CG117BFIT MK74CG117BFILF MK74CG117BFILFT MK74CG117BF MK74CG117BF 74CG117BFLF 74CG117BFLF MK74CG117BFI MK74CG117BFI 74CG117BFILF 74CG117BFILF Tubes Tape and Reel Tubes Tape and Reel Tubes Tape and Reel Tubes Tape and Reel 48-pin SSOP 48-pin SSOP 48-pin SSOP 48-pin SSOP 48-pin SSOP 48-pin SSOP 48-pin SSOP 48-pin SSOP 0 to +70 C 0 to +70 C 0 to +70 C 0 to +70 C -40 to +85 C -40 to +85 C -40 to +85 C -40 to +85 C While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology, Inc. (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. IDTTM 16 OUTPUT LOW SKEW CLOCK GENERATOR 7 MK74CG117B REV D 073108 MK74CG117B 16 OUTPUT LOW SKEW CLOCK GENERATOR 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 (c) 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