ICS85357-11 Integrated Circuit Systems, Inc. 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER GENERAL DESCRIPTION FEATURES The ICS85357-11 is a 4:1 or 2:1, Crystal Oscillator-to-3.3V LVPECL / ECL Multiplexer and HiPerClockS™ is a member of the HiPerClockS™ family of High Performance Clock Solutions from ICS. The ICS85357-11 has 4 selectable crystal inputs. The device can support 10MHz - 25MHz 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). • 1 differential 3.3V LVPECL output ,&6 • 4:1 or 2:1 Crystal Oscillator Multiplexer • Supports parallel resonant crystals with a frequency range of 10MHz - 25MHz. The oscillator circuit is optimized for parallel resonant mode, and will require external capacitance • Maximum output frequency up to 25MHz • LVCMOS SEL0 and SEL1 inputs have internal pulldown resistors • Part-to-part skew: 150ps (maximum) • Propagation delay: 2ns (maximum) • 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 • 0°C to 70°C ambient operating temperature • Industrial temperature information available upon request BLOCK DIAGRAM PIN ASSIGNMENT XTALIN0 OSC 00 OSC 01 XTALOUT0 XTALIN1 Q0 nQ0 XTALOUT1 VCC XTALIN0 XTALOUT0 XTALIN1 XTALOUT1 XTALIN2 XTALOUT2 XTALIN3 XTALOUT3 VEE 10 OSC 11 20 19 18 17 16 15 14 13 12 11 VCC SEL1 SEL0 VCC Q0 nQ0 VCC nc nc VEE ICS85357-11 XTALIN2 OSC 1 2 3 4 5 6 7 8 9 10 20-Lead TSSOP 4.40mm x 6.50mm x 0.92mm body package G Package Top View XTALOUT2 XTALIN3 XTALOUT3 SEL1 SEL0 85357AG-11 www.icst.com/products/hiperclocks.html 1 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER TABLE 1. PIN DESCRIPTIONS Number Name Type Description 1, 14, 17, 20 VCC Power Positive supply pins. Connect to 3.3V. 2 XTALIN0 Input Parallel resonant cr ystal input. 3 XTALOUT0 Input Parallel resonant cr ystal input. 4 XTALIN1 Input Parallel resonant cr ystal input. 5 XTALOUT1 Input Parallel resonant cr ystal input. 6 XTALIN2 Input Parallel resonant cr ystal input. 7 XTALOUT2 Input Parallel resonant cr ystal input. 8 XTALIN3 Input Parallel resonant cr ystal input. 9 XTALOUT3 Input Parallel resonant cr ystal input. 10, 11 VEE Power 12, 13 nc Unused Negative supply pins. Connect to ground. 15, 16 nQ0, Q0 Output 18 SEL0 Input Pulldown Clock select input. LVCMOS / LVTTL interface levels. 19 SEL1 Input Pulldown Clock select input. LVCMOS / LVTTL interface levels. No connect. Differential clock outputs. LVPECL interface levels. NOTE: Pullup and Pulldown 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 RPULLDOWN Input Pulldown Resistor 51 KΩ SEL0, SEL1 TABLE 3A. CONTROL INPUT FUNCTION TABLE Inputs 85357AG-11 Clock Out SEL1 SEL0 CLK 0 0 XTALIN0, XTALOUT0 0 1 XTALIN1, XTALOUT1 1 0 XTALIN2, XTALOUT2 1 1 XTALIN3, XTALOUT3 www.icst.com/products/hiperclocks.html 2 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC 4.6V Inputs, VI Outputs, VO Package Thermal Impedance, θ JA Storage Temperature, TSTG -0.5V to VCC + 0.5V -0.5V to VCC + 0.5V 73.2°C/W (0lfpm) -65°C to 150°C 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. TABLE 4A. POWER SUPPLY DC CHARACTERISTICS, VCC = 3.3V±5%, TA = 0°C TO 70°C Symbol Parameter VCC Positive Supply Voltage Test Conditions IEE Power Supply Current Minimum Typical Maximum Units 3.135 3.3 3.465 V 50 mA Maximum Units 3.765 V TABLE 4B. LVCMOS / LVTTL DC CHARACTERISTICS, VCC = 3.3V±5%, TA = 0°C TO 70°C Symbol Parameter VIH Input High Voltage Test Conditions Minimum SEL0, SEL1 Typical 2 VIL Input Low Voltage SEL0, SEL1 IIH Input High Current SEL0, SEL1 VCC = VIN = 3.465V -0.3 IIL Input Low Current SEL0, SEL1 VCC = 3.465V, VIN = 0V 0.8 V 150 µA -5 µA TABLE 4C. LVPECL DC CHARACTERISTICS, VCC = 3.3V±5%, TA=0°C TO 70°C Symbol Parameter Test Conditions VOH Output High Voltage; NOTE 1 VOL Output Low Voltage; NOTE 1 VSWING Peak-to-Peak Output Voltage Swing Minimum Typical Maximum Units VCC - 1.4 VCC - 1.0 V VCC - 2.0 VCC - 1.7 V 0.6 0.85 V NOTE 1: Outputs terminated with 50Ω to VCC - 2V. 85357AG-11 www.icst.com/products/hiperclocks.html 3 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER TABLE 5. CRYSTAL CHARACTERISTICS Parameter Test Conditions Mode of Oscillation / cut Minimum Typical Maximum Units Fundamental / Parallel Resonant Frequency 10 25 MHz Equivalent Series Resistance (ESR) 50 80 Ω Shunt Capacitance 7 pF Series Pin Inductance 3 7 nH Operating Temperature Range 0 70 °C TABLE 6. AC CHARACTERISTICS, VCC = 3.3V±5%, TA=0°C TO 70°C Symbol Parameter fMAX Output Frequency Range tPD Propagation Delay; NOTE 1 tsk(pp) Par t-to-Par t Skew; NOTE 2, 4 tR Test Conditions Minimum Typical Maximum Units 10 25 MHz ƒ≤ 25MHz 1 2 ns 150 ps Output Rise Time 20% to 80% 300 700 ps tF Output Fall Time 20% to 80% 300 700 ps odc Output Duty Cycle; NOTE 3, 4 47 53 oscTOL Cr ystal Oscillator Tolerance; NOTE 3 ±20 All parameters measured at 25MHz unless noted otherwise. NOTE 1: Measured from the differential input crossing point to the differential output crossing point. Measured overdriving the XTAL input. NOTE 2: Defined as skew between outputs on different devices operating at the same supply voltages and with equal load conditions. Using the same type of inputs on each device, the outputs are measured at the differential cross points. Measured overdriving the XTAL input. NOTE 3: Measured using C1 = 22pF and C2 = 27pF in parallel with 18pF cr ystals. Refer to Figure 6 in the Application Section. NOTE 4: This parameter is defined in accordance with JEDEC Standard 65. 85357AG-11 www.icst.com/products/hiperclocks.html 4 % ppm REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER PARAMETER MEASUREMENT INFORMATION VCC SCOPE Qx LVPECL VCC = 2.0V nQx VEE = -1.3V ± 0.135V FIGURE 1 - OUTPUT LOAD TEST CIRCUIT Q0 PART 1 nQ0 Q0 PART 2 nQ0 tsk(pp) FIGURE 2 - PART-TO-PART SKEW 85357AG-11 www.icst.com/products/hiperclocks.html 5 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER 80% 80% V 20% 20% Clock Inputs and Outputs t t R FIGURE 3 - INPUT V SWING AND OUTPUT RISE AND F FALL TIME /2 CC XTALINx nQ0 Q0 t PD FIGURE 4 - PROPAGATION DELAY Q0 nQ0 Pulse Width t t odc = t PERIOD PW PERIOD FIGURE 5 - odc & tPERIOD 85357AG-11 www.icst.com/products/hiperclocks.html 6 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 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 6. Typical results using parallel 18pF crystals are shown in Table 7. XTAL_IN C1 22p X1 18pF Parallel Crystal XTAL_OUT C2 27p Figure 6. Crystal Input Interface Table 7. Typical Results of Crystal Input Interface Frequency Fine Tuning Crystal Frequency (MHz) C1 (pF) C2 (pF) 14.31818 22 27 15.00 16.66 22 22 19.44 24.00 22 22 85357AG-11 Measured Output Frequency (MHz) Accuracy (PPM) Duty Cycle (%) 14.318011 -12 47.46 27 27 14.999862 16.660162 -9 10 47.70 47.70 27 27 19.440081 24.000183 4 8 46.85 46.00 www.icst.com/products/hiperclocks.html 7 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 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 125°C. The equation for Tj is as follows: Tj = θJA * Pd_total + TA Tj = Junction Temperature θJA = 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 θJA must be used . Assuming a moderate air flow of 200 linear feet per minute and a multi-layer board, the appropriate value is 66.6°C/W per Table 6 below. Therefore, Tj for an ambient temperature of 70°C with all outputs switching is: 70°C + 0.204W * 66.6°C/W = 83.6°C. This is well below the limit of 125°C 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 qJA for 20-pin TSSOP, Forced Convection qJA by Velocity (Linear Feet per Minute) 0 Single-Layer PCB, JEDEC Standard Test Boards 114.5°C/W Multi-Layer PCB, JEDEC Standard Test Boards 73.2°C/W 200 98.0°C/W 66.6°C/W 500 88.0°C/W 63.5°C/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 8 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 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 7. VCC Q1 VOUT RL 50 VCC - 2V FIGURE 7 - LVPECL DRIVER CIRCUIT AND TERMINATION To calculate worst case power dissipation into the load, use the following equations which assume a 50Ω load, and a termination voltage of V - 2V. CC 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 CC_MAX L -V ) OH_MAX Pd_L = [(VOL_MAX – (VCC_MAX - 2V))/R ] * (VCC_MAX - VOL_MAX) L • For logic high, VOUT = V OH_MAX Using V CC_MAX • OH_MAX OL_MAX CC_MAX – 1.0V CC_MAX = 3.465, this results in V For logic low, VOUT = V Using V =V =V CC_MAX = 2.465V – 1.7V = 3.465, this results in V OL_MAX = 1.765V Pd_H = [(2.465V - (3.465V - 2V))/50Ω] * (3.465V - 2.465V) = 20mW Pd_L = [(1.765V - (3.465V - 2V))/50Ω] * (3.465V - 1.765V) = 10.2mW Total Power Dissipation per output pair = Pd_H + Pd_L = 30.2mW 85357AG-11 www.icst.com/products/hiperclocks.html 9 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER RELIABILITY INFORMATION TABLE 9. θJAVS. AIR FLOW TABLE qJA by Velocity (Linear Feet per Minute) 0 Single-Layer PCB, JEDEC Standard Test Boards 114.5°C/W Multi-Layer PCB, JEDEC Standard Test Boards 73.2°C/W 200 98.0°C/W 66.6°C/W 500 88.0°C/W 63.5°C/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 10 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER PACKAGE OUTLINE - G SUFFIX TABLE 10. PACKAGE DIMENSIONS Millimeters SYMBOL MIN N A MAX 20 -- 1.20 A1 0.05 0.15 A2 0.80 1.05 b 0.19 0.30 c 0.09 0.20 D 6.40 6.60 E E1 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 85357AG-11 www.icst.com/products/hiperclocks.html 11 REV. A JULY 25, 2001 ICS85357-11 Integrated Circuit Systems, Inc. 4:1 OR 2:1, CRYSTAL OSCILLATOR-TO-3.3V LVPECL / ECL MULTIPLEXER TABLE 11. ORDERING INFORMATION Part/Order Number Marking Package Count Temperature ICS85357AG-11 ICS85357AG11 20 lead TSSOP 72 per tube 0°C to 70°C ICS85357AG-11T ICS85357AG11 20 lead TSSOP on Tape and Reel 2500 0°C to 70°C 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 12 REV. A JULY 25, 2001