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Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER FEATURES * 1 differential 3.3V LVPECL output * 4:1 or 2:1 Crystal Oscillator Multiplexer * Supports parallel resonant crystals with a frequency range of 10MHz to 27MHz. The oscillator circuit is optimized for parallel resonant mode, and will require external capacitance * Maximum output frequency: 27MHz * LVCMOS/LVTTL SEL0 and SEL1 inputs have internal pulldown resistors * LVPECL mode operating voltage supply range: VCC = 3.135V to 3.465V, VEE = 0V * ECL mode operating voltage supply range: VCC = 0V, VEE = -3.135V to -3.465V * 0C to 70C ambient operating temperature * Industrial temperature information available upon request GENERAL DESCRIPTION The ICS85357-11 is a 4:1 or 2:1, Crystal Oscillator-to-3.3V LVPECL / ECL Multiplexer and HiPerClockSTM is a member of the HiPerClockSTM family of High Performance Clock Solutions from ICS. The ICS85357-11 has 4 selectable crystal inputs. The device can support 10MHz to 27MHz parallel resonant crystals by connecting external capacitors between XTALIN/ XTALOUT and ground. The select pins have internal pulldown resistors and leaving one input unconnected (pulled to logic low by the internal resistor) will transform the device into a 2:1 multiplexer. The SEL1 lead is the most significant line and the binary number applied to the select pins will select the same numbered data input (i.e., 00 selects XTALIN0/XTALOUT0). ICS BLOCK DIAGRAM PIN ASSIGNMENT VCC XTALIN0 XTALOUT0 XTALIN1 XTALOUT1 XTALIN2 XTALOUT2 XTALIN3 XTALOUT3 VEE 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 VCC SEL1 SEL0 VCC Q0 nQ0 VCC nc nc VEE XTALIN0 OSC XT ALOUT0 XTALIN1 OSC XT ALOUT1 XTALIN2 OSC XT ALOUT2 XTALIN3 OSC XT ALOUT3 SEL1 SEL0 11 10 01 Q0 nQ0 00 ICS85357-11 20-Lead TSSOP 4.40mm x 6.50mm x 0.92mm body package G Package Top View 85357AG-11 www.icst.com/products/hiperclocks.html 1 RREV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER Type Power Input Input Input Input Input Input Input Input Power Unused Output Input Input Pulldown Pulldown Description Positive supply pins. Parallel resonant cr ystal input. Parallel resonant cr ystal input. Parallel resonant cr ystal input. Parallel resonant cr ystal input. Parallel resonant cr ystal input. Parallel resonant cr ystal input. Parallel resonant cr ystal input. Parallel resonant cr ystal input. Negative supply pins. No connect. Differential clock outputs. LVPECL interface levels. Clock select input. LVCMOS / LVTTL interface levels. Clock select input. LVCMOS / LVTTL interface levels. TABLE 1. PIN DESCRIPTIONS Number 1, 14, 17, 20 2 3 4 5 6 7 8 9 10, 11 12, 13 15, 16 18 19 Name VCC XTALIN0 XTALOUT0 XTALIN1 XTALOUT1 XTALIN2 XTALOUT2 XTALIN3 XTALOUT3 VEE nc nQ0, Q0 SEL0 SEL1 NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values. TABLE 2. PIN CHARACTERISTICS Symbol CIN RPULLUP RPULLDOWN Parameter Input Capacitance Input Pullup Resistor Input Pulldown Resistor Test Conditions Minimum Typical 4 51 51 Maximum Units pF K K TABLE 3A. CONTROL INPUT FUNCTION TABLE Inputs SEL1 0 0 1 1 SEL0 0 1 0 1 Clock Out CLK XTALIN0, XTALOUT0 XTALIN1, XTALOUT1 XTALIN2, XTALOUT2 XTALIN3, XTALOUT3 85357AG-11 www.icst.com/products/hiperclocks.html 2 REV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER 4.6V -0.5V to VCC + 0.5 V -0.5V to VCC + 0.5V 73.2C/W (0 lfpm) -65C to 150C NOTE: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are stress specifications only. Functional operation of product at these conditions or any conditions beyond those listed in the DC Characteristics or AC Characteristics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability. ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC Inputs, VI Outputs, VO Package Thermal Impedance, JA Storage Temperature, TSTG TABLE 4A. POWER SUPPLY DC CHARACTERISTICS, VCC = 3.3V5%, TA = 0C TO 70C Symbol VCC IEE Parameter Positive Supply Voltage Power Supply Current Test Conditions Minimum 3.135 Typical 3.3 Maximum 3.465 50 Units V mA TABLE 4B. LVCMOS / LVTTL DC CHARACTERISTICS, VCC = 3.3V5%, TA = 0C TO 70C Symbol VIH VIL IIH IIL Parameter Input High Voltage Input Low Voltage Input High Current Input Low Current SEL0, SEL1 SEL0, SEL1 SEL0, SEL1 SEL0, SEL1 VCC = VIN = 3.465V VCC = 3.465V, VIN = 0V -5 Test Conditions Minimum 2 -0.3 Typical Maximum VCC + 0.3 0.8 150 Units V V A A TABLE 4C. LVPECL DC CHARACTERISTICS, VCC = 3.3V5%, TA=0C TO 70C Symbol VOH VOL VSWING Parameter Output High Voltage; NOTE 1 Output Low Voltage; NOTE 1 Peak-to-Peak Output Voltage Swing Test Conditions Minimum VCC - 1.4 VCC - 2.0 0.6 Typical Maximum VCC - 1.0 VCC - 1.7 1.0 Units V V V NOTE 1: Outputs terminated with 50 to VCC - 2V. TABLE 5. CRYSTAL CHARACTERISTICS Parameter Mode of Oscillation / cut Frequency Equivalent Series Resistance (ESR) Shunt Capacitance Test Conditions Minimum 10 Typical Maximum 27 70 7 Units MHz pF Fundamental / Parallel Resonant TABLE 6. AC CHARACTERISTICS, VCC = 3.3V5%, TA=0C TO 70C Symbol Parameter fMAX tR / tF odc Output Frequency Range Output Rise/Fall Time Output Duty Cycle; NOTE 1, 2 20% to 80% Test Conditions Minimum 10 300 47 Typical Maximum 27 700 53 Units MHz ps % oscTOL Cr ystal Oscillator Tolerance; NOTE 1 20 ppm All parameters measured at 25MHz unless noted otherwise. NOTE 1: Measured using C1 = 22pF and C2 = 27pF in parallel with 18pF cr ystals. Refer to Cr ystal Input Interface in the Application Section. NOTE 2: This parameter is defined in accordance with JEDEC Standard 65. 85357AG-11 www.icst.com/products/hiperclocks.html 3 RREV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER PARAMETER MEASUREMENT INFORMATION 2V VCC Qx SCOPE 80% 80% VSW I N G LVPECL nQx VEE Clock Outputs 20% 20% tR tF -1.3V 0.165V 3.3V OUTPUT LOAD AC TEST CIRCUIT OUTPUT RISE/FALL TIME nQ0 Q0 Pulse Width t PERIOD odc = t PW t PERIOD OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD 85357AG-11 www.icst.com/products/hiperclocks.html 4 REV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER APPLICATION INFORMATION CRYSTAL INPUT INTERFACE A crystal can be characterized for either series or parallel mode operation. The ICS85357-11 has a built-in crystal oscillator circuit. This interface can accept either a series or parallel crystal without additional components and generate frequencies with accuracy suitable for most applications. Additional accuracy can be achieved by adding two small capacitors C1 and C2 as shown in Figure 1. Typical results using parallel 18pF crystals are shown in Table 7. XTAL_IN C1 22p X1 18pF Parallel Crystal XTAL_OUT C2 27p Figure 1. Crystal Input Interface Table 7. TYPICAL RESULTS Crystal Frequency (MHz) 14.31818 15.00 16.66 19.44 24.00 OF CRYSTAL INPUT INTERFACE FREQUENCY FINE TUNING C2 (pF) 27 27 27 27 27 Measured Output Frequency (MHz) 14.318011 14.999862 16.660162 19.440081 24.000183 Accuracy (PPM) -12 -9 10 4 8 Duty Cycle (%) 47.46 47.70 47.70 46.85 46.00 C1 (pF) 22 22 22 22 22 85357AG-11 www.icst.com/products/hiperclocks.html 5 RREV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER 50 transmission lines. Matched impedance techniques should be used to maximize operating frequency and minimize signal distortion. Figures 2A and 2B show two different layouts which are recommended only as guidelines. Other suitable clock layouts may exist and it would be recommended that the board designers simulate to guarantee compatibility across all printed circuit and clock component process variations. TERMINATION FOR LVPECL OUTPUTS The clock layout topology shown below is a typical termination for LVPECL outputs. The two different layouts mentioned are recommended only as guidelines. FOUT and nFOUT are low impedance follower outputs that generate ECL/LVPECL compatible outputs. Therefore, terminating resistors (DC current path to ground) or current sources must be used for functionality. These outputs are designed to drive 3.3V Zo = 50 125 FOUT FIN 125 Zo = 50 Zo = 50 50 1 Z ((VOH + VOL) / (VCC - 2)) - 2 o 50 VCC - 2V RTT FOUT FIN Zo = 50 84 84 RTT = FIGURE 2A. LVPECL OUTPUT TERMINATION FIGURE 2B. LVPECL OUTPUT TERMINATION 85357AG-11 www.icst.com/products/hiperclocks.html 6 REV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER POWER CONSIDERATIONS This section provides information on power dissipation and junction temperature for the ICS85357-11. Equations and example calculations are also provided. 1. Power Dissipation. The total power dissipation for the ICS85357-11 is the sum of the core power plus the power dissipated in the load(s). The following is the power dissipation for VCC = 3.3V + 5% = 3.465V, which gives worst case results. NOTE: Please refer to Section 3 for details on calculating power dissipated in the load. * * Power (core)MAX = VCC_MAX * IEE_MAX = 3.465V * 50mA = 173.3mW Power (outputs)MAX = 30.2mW/Loaded Output pair Total Power_MAX (3.465V, with all outputs switching) = 173.3mW + 30.2mW = 203.5mW 2. Junction Temperature. Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the device. The maximum recommended junction temperature for HiPerClockSTM devices is 125C. The equation for Tj is as follows: Tj = JA * Pd_total + TA Tj = Junction Temperature JA = Junction-to-Ambient Thermal Resistance Pd_total = Total Device Power Dissipation (example calculation is in section 1 above) TA = Ambient Temperature In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance JA must be used. Assuming a moderate air flow of 200 linear feet per minute and a multi-layer board, the appropriate value is 66.6C/W per Table 8 below. Therefore, Tj for an ambient temperature of 70C with all outputs switching is: 70C + 0.204W * 66.6C/W = 83.6C. This is well below the limit of 125C This calculation is only an example. Tj will obviously vary depending on the number of loaded outputs, supply voltage, air flow, and the type of board (single layer or multi-layer). TABLE 8. THERMAL RESISTANCE JA FOR 20-PIN TSSOP, FORCED CONVECTION JA by Velocity (Linear Feet per Minute) 0 Single-Layer PCB, JEDEC Standard Test Boards Multi-Layer PCB, JEDEC Standard Test Boards 114.5C/W 73.2C/W 200 98.0C/W 66.6C/W 500 88.0C/W 63.5C/W NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs. 85357AG-11 www.icst.com/products/hiperclocks.html 7 RREV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER 3. Calculations and Equations. The purpose of this section is to derive the power dissipated into the load. LVPECL output driver circuit and termination are shown in Figure 3. VCC Q1 VOUT RL 50 VCC - 2V FIGURE 3. LVPECL DRIVER CIRCUIT AND TERMINATION To calculate worst case power dissipation into the load, use the following equations which assume a 50 load, and a termination voltage of V - 2V. CC * For logic high, VOUT = V (V CCO_MAX OH_MAX =V CC_MAX - 1.0V -V OH_MAX ) = 1.0V =V - 1.7V * For logic low, VOUT = V (V CCO_MAX OL_MAX CC_MAX -V OL_MAX ) = 1.7V Pd_H is power dissipation when the output drives high. Pd_L is the power dissipation when the output drives low. Pd_H = [(V OH_MAX - (V CC_MAX - 2V))/R ] * (V L CC_MAX -V OH_MAX ) = [(2V - (V CC_MAX -V OH_MAX ))/R ] * (V L CC_MAX -V OH_MAX )= [(2V - 1V)/50] * 1V = 20.0mW Pd_L = [(V OL_MAX - (V CC_MAX - 2V))/R ] * (V L CC_MAX -V OL_MAX ) = [(2V - (V CC_MAX -V OL_MAX ))/R ] * (V L CC_MAX -V OL_MAX )= [(2V - 1.7V)/50] * 1.7V = 10.2mW Total Power Dissipation per output pair = Pd_H + Pd_L = 30.2mW 85357AG-11 www.icst.com/products/hiperclocks.html 8 REV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER RELIABILITY INFORMATION TABLE 9. JAVS. AIR FLOW TABLE FOR 20 LEAD TSSOP JA by Velocity (Linear Feet per Minute) 0 200 98.0C/W 66.6C/W 500 88.0C/W 63.5C/W Single-Layer PCB, JEDEC Standard Test Boards Multi-Layer PCB, JEDEC Standard Test Boards 114.5C/W 73.2C/W NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs. TRANSISTOR COUNT The transistor count for ICS85357-11 is: 413 85357AG-11 www.icst.com/products/hiperclocks.html 9 RREV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER 20 LEAD TSSOP PACKAGE OUTLINE - G SUFFIX FOR TABLE 10. PACKAGE DIMENSIONS SYMBOL N A A1 A2 b c D E E1 e L aaa 0.45 0 -4.30 0.65 BASIC 0.75 8 0.10 -0.05 0.80 0.19 0.09 6.40 6.40 BASIC 4.50 Millimeters Minimum 20 1.20 0.15 1.05 0.30 0.20 6.60 Maximum Reference Document: JEDEC Publication 95, MO-153 85357AG-11 www.icst.com/products/hiperclocks.html 10 REV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER Marking Package 20 lead TSSOP 20 lead TSSOP on Tape and Reel Count 72 per tube 2500 Temperature 0C to 70C 0C to 70C TABLE 11. ORDERING INFORMATION Part/Order Number ICS85357AG-11 ICS85357AG-11T 85357AG11 85357AG11 The aforementioned trademark, HiPerClockSTM is a trademark 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 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. 85357AG-11 www.icst.com/products/hiperclocks.html 11 RREV. C OCTOBER 7, 2004 Integrated Circuit Systems, Inc. ICS85357-11 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER REVISION HISTORY SHEET Description of Change Added Termination for LVPECL Outputs section. 3.3V Output Load Test Circuit Diagram, corrected VEE = -1.3V 0.135V to read VEE = -1.3V 0.165V. Revised Output Rise/Fall Time Diagram. LVCMOS table - changed VIH from 3.765 Max. to VCC + 0.3 Max. LVPECL table - changed VSWING from 0.85V Max. to 1.0V Max. AC table - deleted tPD, tsk(pp) and Notes 1 and 2. Updated format. Changed maximum cr ystal frequency from 25MHz to 27MHz. Changed Output Frequency bullet from 25MHz to 27MHz. Pin Characteristics Table - changed CIN from 4pF max. to 4pF typical. Cr ystal Characteristics Table - changed maximum Frequency from 25MHz to 27MHz. AC Characteristics Table - changed maximum Output Frequency Range from 25MHz to 27MHz. Date 5/30/02 8/26/02 Rev A A Table Page 8 5 6 3 3 4 1 T4B B T4C T6 1/16/03 T2 C T5 T6 2 3 3 10/7/04 85357AG-11 www.icst.com/products/hiperclocks.html 12 REV. C OCTOBER 7, 2004 |
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