MK2049-45 3.3V Communications Clock PLL Description Features The MK2049-45 is a dual Phase-Locked Loop (PLL) device which can provide frequency synthesis and jitter attenuation. The first PLL is VCXO based and uses a pullable crystal to track signal wander and attenuate input jitter. The second PLL is a translator for frequency multiplication. Basic configuration is determined by a Mode/Frequency Selection Table. Loop bandwidth and damping factor are programmable via external loop filter component selection. • Packaged in 20 pin SOIC • 3.3 V + 5% operation • Meets the TR62411, ETS300 011, and GR-1244 Buffer Mode accepts a 10 to 50MHz input and will provide a jitter attenuated output at 0.5 x ICLK, 1 x ICLK or 2 x ICLK. In this mode the MK2049-45 is ideal for filtering jitter from high frequency clocks. In External Mode, ICLK accepts an 8 kHz clock and will produce output frequencies from a table of common communciations clock rates, CLK and CLK/2. This allows for the generation of clocks frequency-locked to an 8 kHz backplane clock, simplifying clock synchronization in communications systems. • • • • • • • specification for MTIE, Pull-in/Hold-in Range, Phase Transients, and Jitter Generation for Stratum 3, 4, and 4E Accepts multiple inputs: 8 kHz backplane clock, or 10 to 50 MHz Locks to 8 kHz + 100 ppm (External mode) Buffer Mode allows jitter attenuation of 10 - 50 MHz input and x1 / x0.5 or x1 / x2 outputs Exact internal ratios enable zero ppm error Output rates include T1, E1, T3, E3, and OC3 submultiples Available in Pb (lead) free package See also the MK2049-34 and MK2049-36 The MK2049-45 can be dynamically switched between T1, E1, T3, E3 outputs with the same 24.576 MHz crystal. ICS can customize these devices for many other different frequencies. Contact your ICS representative for more details. Block Diagram RSET ISET Reference Divider (used in buffer mode only) ICLK CS CP CL RS CAP2 CL Optional Crystal Load Caps External Pullable Crystal CAP1 X1 X2 Phase Detector VCXO Charge Pump VCXO PLL Reference Divider Feedback Divider (N) VCO Translator PLL Feedback Divider Output Divider CLK Divide by 2 CLK/2 8k 4 FS3:0 Divider Value Look-up Table MDS 2049-45 G 1 Revision 101904 Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com MK2049-45 3.3V Communications Clock PLL Pin Assignment FS1 X2 1 2 20 19 FS0 RES X1 VDD 3 4 18 17 CAP2 GND FCAP VDD GND CLK CLK/2 8k 5 6 16 15 CAP1 VDD 7 8 9 10 14 13 GND ICLK FS3 FS2 12 11 Pin Descriptions Pin Number Pin Name Pin Type 1 FS1 Input Frequency select 1. Determines CLK input/outputs per table on page 2. Internal pull-up resistor. 2 X2 Input Crystal connection. Connect to a MHz crystal as shown in table on page 2. 3 X1 Input Crystal connection. Connect to a MHz crystal as shown in table on page 2. 4 VDD Power Power supply. Connect to +3.3V. 5 FCAP - 6 VDD Power Power supply. Connect to +3.3V. 7 GND Power Connect to ground 8 CLK Output Clock output determined by status of FS3:0 per tables on page 2. 9 CLK/2 Output Clock output determined by status of FS3:0 per tables page 2. Always 1/2 of CLK. 10 8k Output Recovered 8 kHz clock output. 11 FS2 Input Frequency select 2. Determines CLK input/outputs per table on page 2. Internal pull-up resistor. 12 FS3 Input Frequency select 3. Determines CLK input/outputs per table on page 2. Internal pull-up resistor. 13 ICLK Input Input clock connection. Connect to 8 kHz backplane or MHz clock. 14 GND Power Connect to ground. 15 VDD Power Power Supply. Connect to +3.3V. 16 CAP1 Loop Filter Connect the loop filter capacitors and resistor between this pin and CAP2. 17 GND Power Connect to ground. MDS 2049-45 G Pin Description Filter capacitor. Connect a 1000 pF ceramic capacitor to ground. 2 Revision 101904 Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com MK2049-45 3.3V Communications Clock PLL Pin Number Pin Name Pin Type 18 CAP2 Loop Filter 19 RES - 20 FS0 Input Pin Description Connect the loop filter capacitors and resistor between this pin and CAP1. Connect a resistor to ground. See table. Frequency select 0. Determines CLK input/outputs per table on page 2. Internal pull-up resistor. Output Decoding Table - External Mode (MHz) ICLK 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz FS3 0 0 0 0 0 0 0 0 1 1 1 1 1 1 FS2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 FS1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 FS0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 CLK/2 1.544 2.048 22.368 17.184 19.44 12.8 25.92 4.096 18.528 12.352 24.576 16.384 17.28 62.5 CLK 3.088 4.096 44.736 34.368 38.88 25.6 51.84 8.192 37.056 24.704 49.152 32.768 34.56 125 8k 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz 8 kHz Crystal Used (MHz) 24.576 24.576 24.576 24.576 19.44 25.6 17.28 16.384 24.704 24.704 16.384 16.384 17.28 25 N 3072 3072 3072 3072 2430 3200 2160 2048 3088 3088 2048 2048 2160 3125 Output Decoding Table - Buffer Mode (MHz) ICLK FS3 FS2 FS1 FS0 CLK/2 CLK 8k Crystal N 20 - 50 1 1 1 0 ICLK 2*ICLK N/A ICLK/2 3 10 - 25 1 1 1 1 ICLK/2 ICLK N/A ICLK 3 0 = connect directly to ground, 1 = connect directly to VDD Crystal is connected to pins 2 and 3; clock input is applied to pin 13. Functional Description The MK2049-45 is a clock generator IC that generates an output clock directly from an internal VCXO circuit which works in conjunction with an external quartz crystal. The VCXO is controlled by an internal PLL (Phase Locked Loop) circuit, enabling the device to perform clock regeneration from an input reference clock. The MK2049-45 is configured to provide a high frequency communications reference clock output from MDS 2049-45 G 3 an 8 kHz input clock or to jitter attenuate and buffer a high frequency input clock. There are 14 selectable output frequencies and two buffer mode selections. Please refer to the Output Clock Selection Table on Page 2. Most typical PLL clock devices use an internal VCO (Voltage Controlled Oscillator) for output clock generation. By using a VCXO with an external crystal, Revision 101904 Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com MK2049-45 3.3V Communications Clock PLL the MK2049-45 is able to generate a low jitter, low phase-noise output clock within a low bandwidth PLL. This serves to provide input clock jitter attenuation and enables stable operation with a low frequency reference clock. To obtain a list of qualified crystal devices please visit our website at: The VCXO circuit requires an external pullable crystal for operation. External loop filter components enable a PLL configuration with low loop bandwidth. All analog PLL circuits use a loop filter to establish operating stability. The MK2049-45 uses external loop filter components for the following reasons: Application Information Output Frequency Configuration The MK2049-45 is configured to generate a set of output frequencies from an 8 kHz input clock. Please refer to the Output Clock Selection Table on Page 2. Input bits FS3:0 are set according to this table, as is the external crystal frequency. Please refer to the Quartz Crystal section on this page regarding external crystal requirements. Quartz Crystal It is important that the correct type of quartz crystal is used with the MK2049-45. Failure to do so may result in reduced frequency pullability range, inability of the loop to lock, or excessive output phase jitter. The MK2049-45 operates by phase-locking the VCXO circuit to the input signal of the selected ICLK input. The VCXO consists of the external crystal and the integrated VCXO oscillator circuit. To achieve the best performance and reliability, a crystal device with the recommended parameters (shown below) must be used, and the layout guidelines discussed in the PCB Layout Recommendations section must be followed. The frequency of oscillation of a quartz crystal is determined by its cut and by the external load capacitance. The MK2049-45 incorporates variable load capacitors on-chip which “pull”, or change, the frequency of the crystal. The crystals specified for use with the MK2049-45 are designed to have zero frequency error when the total of on-chip + stray capacitance is 14 pF. To achieve this, the layout should use short traces between the MK2049-45 and the crystal. http://www.icst.com/products/telecom/vcxocrystals.htm PLL Loop Filter Components 1) Larger loop filter capacitor values can be used, allowing a lower loop bandwidth. This enables the use of lower input clock reference frequencies and also input clock jitter attenuation capabilities. Larger loop filter capacitors also allow higher loop damping factors when less passband peaking is desired. 2) The loop filter values can be user selected to optimize loop response characteristics for a given application. Referencing the External Component Schematic on this page, the external loop filter is made up of components RS, CS and CP. RSET establishes PLL charge pump current and therefore influences loop filter characteristics. Tools for optimizing the values of these four components can be found at: http://www.icst.com/products/telecom/ CAP2 CP 0.0003 µF RS 820 kohms CS 0.1 µF CAP1 Figure 3. Typical Loop Filter A complete description of the recommended crystal parameters in the ICS application note, MAN05. MDS 2049-45 G 4 Revision 101904 Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com MK2049-45 3.3V Communications Clock PLL Charge Pump Current Table RSET (kΩ) 13.02 15 16 18 20 22 24 27 36 47 56 75 100 150 200 Recommended Power Supply Connection for Optimal Device Performance Charge Pump Current (ICP) (µA) 139 125 119 109 100 93 86 68 56 43 35 28 22 15 12 Connection to 3.3V Power Plane VDD Pin Bulk Decoupling Capacitor (such as 1 µF Tantalum) VDD Pin 0.01 µF Decoupling Capacitors Crystal Load Capacitors Special considerations must be made in choosing loop components CS and CP. These recommendations can be found at http://www.icst.com/products/telecom/loopfiltercap.htm Series Termination Resistor 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. (The optional series termination resistor is not shown in the External Component Schematic.) Decoupling Capacitors As with any high performance mixed-signal IC, the MK2049-45 must be isolated from system power supply noise to perform optimally. Decoupling capacitors of 0.01µF must be connected between each VDD and the PCB ground plane. To further guard against interfering system supply noise, the MK2049-45 should use one common connection to the PCB power plane as shown in the diagram on the next page. The ferrite bead and bulk capacitor help reduce lower frequency noise in the supply that can lead to output clock phase modulation. MDS 2049-45 G VDD Pin Ferrite Bead 5 The device crystal connections should include pads for small capacitors from X1 to ground and from X2 to ground, shown as CL in the External Component Schematic. 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) been the crystal and device. Please refer to MAN05 for the procedure to determine capacitor values. PCB Layout Recommendations For optimum device performance and lowest output phase noise, the following guidelines should be observed. Please also refer to the Recommended PCB Layout drawing on Page 7. 1) Each 0.01 µF decoupling capacitor should be mounted on the component side of the board as close to the VDD pin as possible. No via’s 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. Distance of the ferrite bead and bulk decoupling from the device is less critical. 2) The loop filter components must also be placed close to the CHGP and VIN pins. CP should be closest to the device. Coupling of noise from other system Revision 101904 Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com MK2049-45 3.3V Communications Clock PLL signal traces should be minimized by keeping traces short and away from active signal traces. Use of vias should be avoided. 3) 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 they should be separated and away from other traces. signal layers (the ferrite bead and bulk decoupling capacitor can be mounted on the back). Other signal traces should be routed away from the MK2049-45. This includes signal traces just underneath the device, or on layers adjacent to the ground plane layer used by the device. MAN05 may also be referenced for additional suggestions on layout of the crystal section. 4) To minimize EMI the 33 Ω series termination resistor, if needed, should be placed close to the clock output. 5) An optimum layout is one with all components on the same side of the board, minimizing vias through other Absolute Maximum Ratings Stresses above the ratings listed below can cause permanent damage to the MK2049-45. These ratings, which are standard values for ICS 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 -40 to +85°C Storage Temperature -65 to +150°C Junction Temperature 125°C Soldering Temperature 250°C Recommended Operation Conditions Parameter Min. Ambient Operating Temperature -40 Power Supply Voltage (measured in respect to GND) MDS 2049-45 G Typ. 6 +3.15 +3.3 Max. Units +85 °C +3.45 V Revision 101904 Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com MK2049-45 3.3V Communications Clock PLL DC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V ±5%, Ambient Temperature -40 to +85°C Parameter Symbol Conditions Min. Typ. Max. Units 3.15 3.3 3.45 V Operating Voltage VDD Supply Current IDD Input High Voltage VIH Input Low Voltage VIL Input High Current IIH VIH = VDD Input Low Current IIL VIL = 0 Input Capacitance, except X1 CIN Output High Voltage (CMOS Level) VOH IOH = -4 mA VDD-0.4 V Output High Voltage VOH IOH = -8 mA 2.4 V Output Low Voltage VOL IOL = 8 mA Short Circuit Current IOS VIN, VCXO Control Voltage VXC Clock outputs unloaded, VDD = 3.3V 25 mA 2 V 0.8 V -10 +10 µA -10 +10 µA 7 pF 0.4 ±50 0 V mA VDD V AC Electrical Characteristics Unless stated otherwise, VDD = 3.3 V ±5%, Ambient Temperature -40 to +85° C Parameter VCXO Crystal Pull Range Symbol fXP Conditions Using Recommended Crystal Min. Typ. -115 Max. Units +115 ppm 0.4 UI Input Jitter Tolerance tji Input pulse width (1) tpi Output Duty Cycle (% high time) tOD Measured at VDD/2, CL=15pF Output Rise Time tOR 0.8 to 2.0V, CL=15 pF 1.0 ns Output Fall Time tOF 2.0 to 0.8V, CL=15 pF 1.0 ns Skew, ICLK to Output Clock Note 2 tIO All output clock selections except 1.544 and 2.048 MHz Timing Jitter, Filtered 500Hz-1.3MHz (OC-3) tjf Referenced to Mitel/Zarlink MT9045, Note 3 MDS 2049-45 G In reference to input clock period 10 7 ns 40 60 -5 +5 400 % ns ps Revision 101904 Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com MK2049-45 3.3V Communications Clock PLL Parameter Symbol Timing Jitter, Filtered 65kHz-1.3MHz (OC-3) tjf Conditions Referenced to Mitel/Zarlink MT9045, Note 3 Frequency Error Relative to ICLK Nominal Output Impedance ZOUT Min. Typ. Max. Units 230 ps 0 ppm 20 Ω Note 1: Minimum high or low time of input clock. Note 2: For the 1.544 MHz and 2.048 MHz output selections, the input to output clock skew is not controlled nor predictable and will change between power up cycles. Because it is dependent on the phase relationship between the output and feedback divider states following power up, the input to output clock skew will remain stable during a given power up cycle. If controlled input to output skew is desired for this output clock frequency please refer to the MK2049 or MK2069 products. Note 3: Input reference is the 8 kHz output from a Mitel/Zarlink MT9045 device in freerun mode (SEL2:0 = 100, 19.44 MHz external crystal). Marking Diagram 20 11 MK2049-45SI ###### YYWW 10 1 Marking Diagram (Pb free) 20 11 MK2049-45SILF ###### YYWW 1 10 Notes: 1. ###### is the lot number. 2. YYWW is the last two digits of the year and the week that the part was assembled. 3. “LF” designates Pb (lead) free package. MDS 2049-45 G 8 Revision 101904 Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com MK2049-45 3.3V Communications Clock PLL Package Outline and Package Dimensions (20 pin SOIC, 300 Mil. Wide Body) Package dimensions are kept current with JEDEC Publication No. 95 Millimeters Symbol A A1 A2 B C D E e H h L α In d e x A re a E H 1 2 h x 45o D Min A2 A1 Max -2.65 1.10 -2.05 2.55 0.33 0.51 0.18 0.32 12.60 13.00 7.40 7.60 1.27 Basic 10.00 10.65 0.25 0.75 0.40 1.27 0° 8° Inches Min Max -0.104 0.0040 -0.081 0.100 0.013 0.020 0.007 0.013 0.496 0.512 0.291 0.299 0.050 Basic 0.394 0.419 0.010 0.029 0.016 0.050 0° 8° A e L C B Ordering Information Part / Order Number Marking Shipping Packaging Package Temperature MK2049-45SI MK2049-45SI Tubes 20-pin SOIC -40 to +85° C MK2049-45SITR MK2049-45SI Tape and Reel 20-pin SOIC -40 to +85° C MK2049-45SILF MK2049-45SILF Tubes 20-pin SOIC -40 to +85° C MK2049-45SILFTR MK2049-45SILF Tape and Reel 20-pin SOIC -40 to +85° C “LF” denotes Pb (lead) free package. While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems (ICS) 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 ICS. ICS reserves the right to change any circuitry or specifications without notice. ICS does not authorize or warrant any ICS product for use in life support devices or critical medical instruments. MDS 2049-45 G 9 Revision 101904 Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com