PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR GENERAL DESCRIPTION F EATURES The ICS844031I-01 is an Ethernet Clock Generator and a member of the HiPerClocksTM HiPerClockS™ family of high performance devices from ICS. The ICS844031I-01 uses an 18pF parallel resonant crystal over the range of 19.6MHz - 27.2MHz. For Ethernet applications, a 25MHz crystal is used to generate 312.5MHz. The ICS844031I-01 has excellent <1ps phase jitter performance, over the 1.875MHz - 20MHz integration range. The ICS844031I-01 is packaged in a small 8-pin TSSOP, making it ideal for use in systems with limited board space. • (1) Differential LVDS output ICS • Crystal oscillator interface, 18pF parallel resonant crystal (19.6MHz - 27.2MHz) • Output frequency range: 245MHz - 340MHz • VCO range: 490MHz - 680MHz • RMS phase jitter @ 312.5MHz, using a 25MHz crystal (1.875MHz - 20MHz): 0.49ps (typical) • 3.3V or 2.5V operating supply • -40°C to 85°C ambient operating temperature COMMON CONFIGURATION TABLE Inputs Crystal Frequency (MHz) M N 25 25 2 Multiplication Value M/N 12.5 Output Frequency (MHz) 312.5 BLOCK DIAGRAM PIN ASSIGNMENT OE Pullup XTAL_IN OSC XTAL_OUT Phase Detector VCO 490MHz - 680MHz N = ÷2 (fixed) Q nQ VDDA GND XTAL_OUT XTAL_IN 1 2 3 4 8 7 6 5 VDD Q nQ OE ICS844031I-01 8-Lead TSSOP 4.40mm x 3.0mm x 0.925mm package body G Package Top View M = ÷25 (fixed) The Preliminary Information presented herein represents a product in prototyping or pre-production. The noted characteristics are based on initial product characterization. Integrated Circuit Systems, Incorporated (ICS) reserves the right to change any circuitry or specifications without notice. 844031AGI-01 www.icst.com/products/hiperclocks.html REV. B JULY 6, 2005 1 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR TABLE 1. PIN DESCRIPTIONS Number Name 1 VDDA Power Type Description Analog supply pin. 2 GND Power 3, 4 XTAL_OUT, XTAL_IN Input 5 OE Input 6, 7 nQ, Q Output Power supply ground. Cr ystal oscillator interface. XTAL_IN is the input, XTAL_OUT is the output. Output enable pin. When HIGH, Q0/nQ0 output is active. When LOW, the Q0/nQ0 output is in a high impedance state. LVCMOS/LVTTL interface levels. Differential clock outputs. LVDS interface levels. 8 VDD Power Core supply pin. Pullup NOTE: Pullup refers to internal input resistors. See Table 2, Pin Characteristics, for typical values. TABLE 2. PIN CHARACTERISTICS Symbol Parameter Test Conditions Minimum Typical Maximum Units CIN Input Capacitance 4 pF RPULLUP Input Pullup Resistor 51 kΩ 844031AGI-01 www.icst.com/products/hiperclocks.html 2 REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR ABSOLUTE MAXIMUM RATINGS Supply Voltage, VDD 4.6V NOTE: Stresses beyond those listed under Absolute Inputs, VI -0.5V to VDD + 0.5 V Maximum Ratings may cause permanent damage to the device. These ratings are stress specifications only. Functional Outputs, IO (LVDS) Continuous Current Surge Current 10mA 15mA Package Thermal Impedance, θJA 101.7°C/W (0 mps) Storage Temperature, TSTG -65°C to 150°C operation of product at these conditions or any conditions beyond those listed in the DC Characteristics or AC Character- istics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability. TABLE 3A. POWER SUPPLY DC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, TA = -40°C TO 85°C Symbol Parameter VDD Test Conditions Minimum Typical Maximum Units Core Supply Voltage 3.135 3.3 3.465 V 3.135 3.3 3.465 VDDA Analog Supply Voltage IDD Power Supply Current TBD mA IDDA Analog Supply Current TBD mA V TABLE 3B. POWER SUPPLY DC CHARACTERISTICS, VDD = VDDA = 2.5V±5%, TA = -40°C TO 85°C Symbol Parameter Test Conditions Minimum Typical Maximum Units VDD Core Supply Voltage 2.375 2.5 2.625 V VDDA Analog Supply Voltage 2.375 2.5 2.625 V IDD Power Supply Current TBD mA IDDA Analog Supply Current TBD mA TABLE 3C. LVCMOS/LVTTL DC CHARACTERISTICS, VDD = VDDA = 3.3V±5% OR 2.5V±5%, TA = -40°C TO 85°C Symbol Parameter Test Conditions Minimum Maximum Units VDD = 3.3V 2 VDD + 0.3 V VDD = 2.5V 1.7 VDD + 0.3 V VDD = 3.3V -0.3 0.8 V VDD = 2.5V -0.3 0.7 V 5 µA VIH Input High Voltage VIL Input Low Voltage IIH Input High Current OE VDD = VIN = 3.465V or 2.625V IIL Input Low Current OE VDD = 3.465V or 2.625V, VIN = 0V Typical -150 µA TABLE 3D. LVDS DC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, TA = -40°C TO 85°C Symbol Parameter VOD Differential Output Voltage Δ VOD VOD Magnitude Change VOS Offset Voltage Δ VOS VOS Magnitude Change Test Conditions Minimum Typical Maximum Units 350 mV 40 mV 1.25 V 50 mV NOTE: Please refer to Parameter Measurement Information for output information. 844031AGI-01 www.icst.com/products/hiperclocks.html 3 REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR TABLE 3E. LVDS DC CHARACTERISTICS, VDD = VDDA = 2.5V±5%, TA = -40°C TO 85°C Symbol Parameter VOD Differential Output Voltage Test Conditions Minimum Typical 350 Maximum Units mV Δ VOD VOD Magnitude Change 50 mV VOS Offset Voltage 1.2 V Δ VOS VOS Magnitude Change 40 mV NOTE: Please refer to Parameter Measurement Information for output information. TABLE 4. CRYSTAL CHARACTERISTICS Parameter Test Conditions Minimum Mode of Oscillation Typical Maximum Units Fundamental 27.2 MHz Equivalent Series Resistance (ESR) Frequency 19.6 50 Ω Shunt Capacitance 7 pF Drive Level 1 mW Maximum Units 340 MHz TABLE 5A. AC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, TA = -40°C TO 85°C Symbol Parameter fOUT Output Frequency RMS Phase Jitter ( Random); NOTE 1 Output Rise/Fall Time tjit(Ø) tR / tF Test Conditions Minimum Typical 245 312.5MHz @ Integration Range: 1.875MHz - 20MHz 20% to 80% odc Output Duty Cycle NOTE 1: Please refer to the Phase Noise Plots following this section. 0.49 ps 300 ps 50 % TABLE 5B. AC CHARACTERISTICS, VDD = VDDA = 2.5V±5%, TA = -40°C TO 85°C Symbol Parameter fOUT Output Frequency RMS Phase Jitter ( Random); NOTE 1 Output Rise/Fall Time tjit(Ø) tR / tF Test Conditions Typical 245 312.5MHz @ Integration Range: 1.875MHz - 20MHz 20% to 80% odc Output Duty Cycle NOTE 1: Please refer to the Phase Noise Plots following this section. 844031AGI-01 Minimum www.icst.com/products/hiperclocks.html 4 Maximum Units 340 MHz 0.70 ps 300 ps 50 % REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR TYPICAL PHASE NOISE AT 312.5MHZ ➤ 0 -10 -20 Ethernet Filter -40 312.5MHz -50 -60 RMS Phase Jitter (Random) 1.875MHz to 20MHz = 0.49ps (typical) -70 -80 Raw Phase Noise Data -90 -100 ➤ NOISE POWER dBc Hz -30 -110 -120 -130 -140 -150 ➤ -160 -170 -180 -190 100 1k Phase Noise Result by adding an Ethernet Filter to raw data 10k 100k 1M 10M 100M OFFSET FREQUENCY (HZ) 844031AGI-01 www.icst.com/products/hiperclocks.html 5 REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR PARAMETER MEASUREMENT INFORMATION SCOPE Qx 3.3V±5% POWER SUPPLY Qx 2.5V±5% POWER SUPPLY LVDS + Float GND - + Float GND - SCOPE LVDS nQx nQx LVDS 3.3V OUTPUT LOAD AC TEST CIRCUIT LVDS 2.5V OUTPUT LOAD AC TEST CIRCUIT Phase Noise Plot Noise Power nQ Q t PW t Phase Noise Mask odc = f1 Offset Frequency PERIOD t PW x 100% t PERIOD f2 RMS Jitter = Area Under the Masked Phase Noise Plot RMS PHASE JITTER OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD VVDD DD out 80% DC Input VSW I N G Clock Outputs LVDS ➤ 80% 20% 20% tR out tF ➤ VOS/Δ VOS ➤ OFFSET VOLTAGE SETUP OUTPUT RISE/FALL TIME VDD V DD LVDS 100 ➤ VOD/Δ VOD out ➤ DC Input ➤ out DIFFERENTIAL OUTPUT VOLTAGE SETUP 844031AGI-01 www.icst.com/products/hiperclocks.html 6 REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR APPLICATION INFORMATION POWER SUPPLY FILTERING TECHNIQUES As in any high speed analog circuitry, the power supply pins are vulnerable to random noise. The ICS844031I-01 provides separate power supplies to isolate any high switching noise from the outputs to the internal PLL. VDD and VDDA should be individually connected to the power supply plane through vias, and bypass capacitors should be used for each pin. To achieve optimum jitter performance, power supply isolation is required. Figure 1 illustrates how a 10Ω resistor along with a 10μF and a .01μF bypass capacitor should be connected to each VDDA pin. 3.3V or 2.5V VDD .01μF 10 Ω VDDA .01μF 10μF FIGURE 1. POWER SUPPLY FILTERING CRYSTAL INPUT INTERFACE The ICS844031I-01 has been characterized with 18pF parallel resonant crystals. The capacitor values, C1 and C2, shown in Figure 2 below were determined using a 25MHz, 18pF parallel resonant crystal and were chosen to minimize the ppm error. The optimum C1 and C2 values can be slightly adjusted for different board layouts. XTAL_OUT C1 33p X1 18pF Parallel Crystal XTAL_IN C2 27p Figure 2. CRYSTAL INPUt INTERFACE 844031AGI-01 www.icst.com/products/hiperclocks.html 7 REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR 3.3V, 2.5V LVDS DRIVER TERMINATION A general LVDS interface is shown in Figure 3. In a 100Ω differential transmission line environment, LVDS drivers require a matched load termination of 100Ω across near the receiver input. For a multiple LVDS outputs buffer, if only partial outputs are used, it is recommended to terminate the un-used outputs. 2.5V or 3.3V VDD LVDS_Driv er + R1 100 - 100 Ohm Differential Transmission Line FIGURE 3. TYPICAL LVDS DRIVER TERMINATION 844031AGI-01 www.icst.com/products/hiperclocks.html 8 REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR APPLICATION SCHEMATIC Figure 4A provides a schematic example of ICS844031I. In this example, an 18 pF parallel resonant crystal is used. The C1=22pF and C2=22pF are recommended for frequency. The C1 and C2 values may be slightly adjusted for optimizing fre- VDD quency accuracy. At least one decoupling capacitor near the power pin is required. Suggested value range is from 0.01uF to 0.1uF. Other filter type can be added depending on the system power supply noise type. VDDA VDD R2 10 C3 10uF C4 0.01u R1 1K U1 Zo = 50 Ohm 1 2 3 4 C2 22pF VCCA GND XTAL_OUT XTAL_IN VDD Q0 nQ0 OE VDD 8 7 6 5 + R3 100 Zo = 50 Ohm X1 CL=18pF ICS844031 C5 0.1u LVDS C1 22pF VDD= 3.3V or 2.5V FIGURE 4A. APPLICATION SCHEMATIC EXAMPLE PC BOARD LAYOUT EXAMPLE Figure 4B shows an example of ICS844031I P.C. board layout. The crystal X1 footprint shown in this example allows installation of either surface mount HC49S or through-hole HC49 package. The footprints of other components in this example are listed in the Table 6. There should be at least one decoupling capacitor per power pin. The decoupling capacitors should be located as close as possible to the power pins. The layout assumes that the board has clean analog power ground plane. TABLE 6. FOOTPRINT TABLE Reference Size C1, C2 0402 C3 0805 C4, C5 0603 R2 0603 NOTE: Table 6, lists component sizes shown in this layout example. FIGURE 4B. ICS843001 PC BOARD LAYOUT EXAMPLE 844031AGI-01 www.icst.com/products/hiperclocks.html 8 REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR RELIABILITY INFORMATION TABLE 7. θJAVS. AIR FLOW TABLE FOR 8 LEAD TSSOP θJA by Velocity (Meters per Second) Multi-Layer PCB, JEDEC Standard Test Boards 0 1 2.5 101.7°C/W 90.5°C/W 89.8°C/W TRANSISTOR COUNT The transistor count for ICS844031I-01 is: 2519 844031AGI-01 www.icst.com/products/hiperclocks.html 10 REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. PACKAGE OUTLINE - G SUFFIX FOR ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR 8 LEAD TSSOP TABLE 8. PACKAGE DIMENSIONS SYMBOL Millimeters Minimum N Maximum 8 A -- 1.20 A1 0.05 0.15 A2 0.80 1.05 b 0.19 0.30 c 0.09 0.20 D 2.90 E E1 3.10 6.40 BASIC 4.30 e 4.50 0.65 BASIC L 0.45 0.75 α 0° 8° aaa -- 0.10 Reference Document: JEDEC Publication 95, MO-153 844031AGI-01 www.icst.com/products/hiperclocks.html 11 REV. B JULY 6, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS844031I-01 FEMTOCLOCKS™ CRYSTAL-TO- LVDS CLOCK GENERATOR TABLE 9. ORDERING INFORMATION Part/Order Number Marking Package Shipping Packaging Temperature ICS844031AGI-01 TBD 8 lead TSSOP tube -40°C to 85°C ICS844031AGI-01T TBD 8 lead TSSOP 2500 tape & reel -40°C to 85°C The aforementioned trademarks, HiPerClockS™ and FemtoClocks™ are trademarks of Integrated Circuit Systems, Inc. or its subsidiaries in the United States and/or other countries. While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems, Incorporated (ICS) assumes no responsibility for either its use or for 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 and industrial applications. Any other applications such as those requiring 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. 844031AGI-01 www.icst.com/products/hiperclocks.html 12 REV. B JULY 6, 2005