ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER GENERAL DESCRIPTION FEATURES The ICS85211I-01 is a low skew, high performance 1-to-2 Differential-to-HSTL Fanout Buffer HiPerClockS™ and a member of the HiPerClockS™ family of High Performance Clock Solutions from ICS. The CLK, nCLK pair can accept most standard differential input levels.The ICS85211I-01 is characterized to operate from a 3.3V power supply. Guaranteed output and part-to-part skew characteristics make the ICS85211I-01 ideal for those clock distribution applications demanding well defined performance and repeatability. For optimal performance, terminate all outputs. • Two differential HSTL compatible outputs ICS • One differential CLK, nCLK input pair • CLK, nCLK pair can accept the following differential input levels: LVDS, LVPECL, HSTL, SSTL, HCSL • Maximum output frequency: 700MHz • Translates any single-ended input signal to HSTL levels with resistor bias on nCLK input • Output skew: 30ps (maximum) • Part-to-part skew: 250ps (maximum) • Propagation delay: 1ns (maximum) • Output crossover Voltage: 0.68V to 0.9V • Output duty cycle: 49% - 51% up to 266.6MHz • VOH = 1.4V (maximum) • 3.3V operating supply • -40°C to 85°C ambient operating temperature • Available in both standard and lead-free RoHS-compliant packages BLOCK DIAGRAM CLK nCLK PIN ASSIGNMENT Q0 nQ0 Q1 nQ1 Q0 nQ0 Q1 nQ1 1 2 3 4 8 7 6 5 VDD CLK nCLK GND ICS85211I-01 8-Lead SOIC 3.90mm x 4.90mm x 1.37mm package body M Package Top View 85211AMI-01 www.icst.com/products/hiperclocks.html 1 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER TABLE 1. PIN DESCRIPTIONS Number Name 1, 2 Q0, nQ0 Output Type Description 3, 4 Q1, nQ1 Output Differential output pair. HSTL interface levels. 5 GN D Power Power supply ground. 6 nCLK Input 7 CLK Input 8 VDD Power Differential output pair. HSTL interface levels. Pullup/ Pulldown Pulldown Inver ting differential clock input. VDD/2 default when left floating. Non-inver ting differential clock input. Positive supply pin. NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values. TABLE 2. PIN CHARACTERISTICS Symbol Parameter CIN Input Capacitance Test Conditions Minimum Typical 4 Maximum Units pF RPULLUP Input Pullup Resistor 51 kΩ RPULLDOWN Input Pulldown Resistor 51 kΩ TABLE 3. CLOCK INPUT FUNCTION TABLE Inputs Outputs CLK nCLK Q0, Q1 nQ0, nQ1 0 0 LOW HIGH Input to Output Mode Polarity Differential to Differential Non Inver ting 1 1 HIGH LOW Differential to Differential Non Inver ting 0 Biased; NOTE 1 LOW HIGH Single Ended to Differential Non Inver ting 1 Biased; NOTE 1 HIGH LOW Single Ended to Differential Non Inver ting Biased; NOTE 1 0 HIGH LOW Single Ended to Differential Inver ting Biased; NOTE 1 1 LOW HIGH Single Ended to Differential Inver ting NOTE 1: Please refer to the Application Information section, "Wiring the Differential Input to Accept Single Ended Levels". 85211AMI-01 www.icst.com/products/hiperclocks.html 2 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER ABSOLUTE MAXIMUM RATINGS Supply Voltage, VDD 4.6V Inputs, VDD -0.5V to VDD + 0.5 V Outputs, VDD -0.5V to VDD + 0.5V Package Thermal Impedance, θJA 112.7°C/W (0 lfpm) Storage Temperature, TSTG -65°C to 150°C 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. TABLE 4A. POWER SUPPLY DC CHARACTERISTICS, VDD = 3.3V ± 5%, TA = -40°C TO 85°C Symbol Parameter VDD Power Supply Voltage Test Conditions IDD Power Supply Current Minimum Typical Maximum Units 3.135 3.3 3.465 V 22 mA Maximum Units TABLE 4B. DIFFERENTIAL DC CHARACTERISTICS, VDD = 3.3V ± 5%, TA = -40°C TO 85°C Symbol Parameter IIH Input High Current IIL Input Low Current Test Conditions Minimum Typical nCLK VDD = VIN = 3.465V 150 µA CLK VDD = VIN = 3.465V 150 µA nCLK VDD = 3.465V, VIN = 0V -150 µA CLK VDD = 3.465V, VIN = 0V -5 µA Peak-to-Peak Input Voltage 0.15 Common Mode Input Voltage; VCMR 0.5 NOTE 1, 2 NOTE 1: For single ended applications the maximum input voltage for CLK and nCLK is VDD + 0.3V. NOTE 2: Common mode voltage is defined as VIH. 1.3 V VDD - 0.85 V Maximum Units 1.0 1.4 V VPP TABLE 4C. HSTL DC CHARACTERISTICS, VDD = 3.3V ± 5%, TA = -40°C TO 85°C Symbol Parameter VOH Output High Voltage; NOTE 1 Test Conditions Minimum Typical VOL Output Low Voltage; NOTE 1 0 0.4 V VOX Output Crossover Voltage 0.68 0.9 V VSWING Peak-to-Peak Output Voltage Swing 0.6 1.4 V 1.0 NOTE 1: All outputs must be terminated with 50Ω to ground. 85211AMI-01 www.icst.com/products/hiperclocks.html 3 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER TABLE 5. AC CHARACTERISTICS, VDD = 3.3V ± 5%, TA = -40°C TO 85°C Symbol Parameter fMAX Output Frequency tPD Propagation Delay; NOTE 1 t sk(o) Output Skew; NOTE 2, 4 t sk(pp) Par t-to-Par t Skew; NOTE 3, 4 tR / tF Output Rise/Fall Time odc Output Duty Cycle Test Conditions ƒ≤ 600MHz 20% to 80% Minimum 0.7 Typical Maximum Units 700 MHz 1.0 ns 30 ps 250 ps 200 500 ps 48 52 % ƒ≤ 266.6MHz 49 51 % All parameters measured at 600MHz unless noted otherwise. The cycle-to-cycle jitter on the input will equal the jitter on the output. The par t does not add jitter. NOTE 1: Measured from the differential input crossing point to the differential output crossing point. NOTE 2: Defined as skew between outputs at the same supply voltage and with equal load conditions. Measured at output differential cross points. NOTE 3: 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. NOTE 4: This parameter is defined in accordance with JEDEC Standard 65. 85211AMI-01 www.icst.com/products/hiperclocks.html 4 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER PARAMETER MEASUREMENT INFORMATION 3.3V±5% V DD Qx V DD SCOPE nCLK HSTL V Cross Points PP V CMR CLK nQx GND GND 0V 3.3V OUTPUT LOAD AC TEST CIRCUIT DIFFERENTIAL INPUT LEVEL nQx Qx PART 1 nQx Qx Qy PART 2 nQy nQy Qy tsk(pp) tsk(o) OUTPUT SKEW PART-TO-PART SKEW nCLK 80% 80% CLK VSW I N G Clock Outputs nQ0, nQ1 20% 20% tF tR Q0, Q1 tPD OUTPUT RISE/FALL TIME PROPAGATION DELAY nQ0, nQ1 Q0, Q1 t PW t odc = PERIOD t PW x 100% t PERIOD OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD 85211AMI-01 www.icst.com/products/hiperclocks.html 5 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER APPLICATION INFORMATION WIRING THE DIFFERENTIAL INPUT TO ACCEPT SINGLE ENDED LEVELS Figure 1 shows how the differential input can be wired to accept single ended levels. The reference voltage V_REF = VDD/2 is generated by the bias resistors R1, R2 and C1. This bias circuit should be located as close as possible to the input pin. The ratio of R1 and R2 might need to be adjusted to position the V_REF in the center of the input voltage swing. For example, if the input clock swing is only 2.5V and VDD = 3.3V, V_REF should be 1.25V and R2/R1 = 0.609. VDD R1 1K Single Ended Clock Input CLK V_REF nCLK C1 0.1u R2 1K FIGURE 1. SINGLE ENDED SIGNAL DRIVING DIFFERENTIAL INPUT SCHEMATIC EXAMPLE Figure 2 shows a schematic example of ICS85211I-01. In this example, the input is driven by an ICS HiPerClockS HSTL driver. The decoupling capacitors should be physically located near the power pin. For ICS85211I-01, the unused outputs need to be terminated. Zo = 50 Ohm 1.8V - U1 Zo = 50 Ohm 5 6 7 8 Zo = 50 Ohm nQ1 Q1 nQ0 Q0 VDD=3.3V LVHSTL ICS HiPerClockS LVHSTL Driv er GND nCLK CLK VDD R6 50 R5 50 4 3 2 1 Zo = 50 Ohm + R1 50 R2 50 LVHSTL Input ICS85211-01 C1 0.1u R3 50 Unused R4 Output 50 Need To Be Terminated FIGURE 2. ICS85211I-01 HSTL BUFFER SCHEMATIC EXAMPLE 85211AMI-01 www.icst.com/products/hiperclocks.html 6 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER RECOMMENDATIONS FOR UNUSED OUTPUT PINS OUTPUTS: HSTL OUTPUT All unused HSTL outputs can be left floating. We recommend that there is no trace attached. Both sides of the differential output pair should either be left floating or terminated. CLOCK INPUT INTERFACE of the driver components to confirm the driver termination requirement. For example in Figure 3, the input termination applies for ICS HiPerClockS HSTL drivers. If you are using an HSTL driver from another vendor, use their termination recommendation. The CLK /nCLK accepts differential input signals of both VSWING and VOH to meet the VPP and VCMR input requirements. Figures 3A to 3D show interface examples for the ICS85211I-01 clock input driven by most common driver types. The input interfaces suggested here are examples only. Please consult with the vendor 3.3V 3.3V 3.3V 1.8V Zo = 50 Ohm CLK Zo = 50 Ohm CLK Zo = 50 Ohm nCLK Zo = 50 Ohm HiPerClockS Input LVHSTL ICS HiPerClockS LVHSTL Driver R1 50 HiPerClockS Input LVPECL nCLK R1 50 R2 50 R2 50 R3 50 FIGURE 3A. ICS85211I-01 CLK/NCLK INPUT DRIVEN HIPERCLOCKS HSTL DRIVER FIGURE 3B. ICS85211I-01 CLK/NCLK INPUT DRIVEN 3.3V LVPECL DRIVER (INTERFACE 1) BY BY 3.3V 3.3V 3.3V 3.3V 3.3V 3.3V R3 125 R4 125 LVPECL Zo = 50 Ohm C1 Zo = 50 Ohm C2 R3 125 R4 125 Zo = 50 Ohm CLK CLK Zo = 50 Ohm nCLK nCLK LVPECL R1 84 HiPerClockS Input R5 100-200 R2 84 R6 100-200 R1 84 HiPerClockS Input R2 84 R5,R6 locate near the driv er pin. FIGURE 3C. ICS85211I-01 CLK/NCLK INPUT DRIVEN 3.3V LVPECL DRIVER (INTERFACE 2) 85211AMI-01 FIGURE 3D. ICS85211I-01 CLK/NCLK INPUT DRIVEN 3.3V LVPECL DRIVER WITH AC COUPLE BY www.icst.com/products/hiperclocks.html 7 BY REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER POWER CONSIDERATIONS This section provides information on power dissipation and junction temperature for the ICS85211I-01. Equations and example calculations are also provided. 1. Power Dissipation. The total power dissipation for the ICS85211I-01 is the sum of the core power plus the power dissipated in the load(s). The following is the power dissipation for VDD = 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 = VDD_MAX * IDD_MAX = 3.465V * 22mA = 76.2mW Power (outputs)MAX = 82.34mW/Loaded Output pair If all outputs are loaded, the total power is 2 * 82.34mW = 164.7mW Total Power_MAX (3.465V, with all outputs switching) = 76.2mW + 164.7mW = 240.9mW 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 103.3°C/W per Table 6 below. Therefore, Tj for an ambient temperature of 85°C with all outputs switching is: 85°C + 0.241W * 103.3°C/W = 110°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 6. THERMAL RESISTANCE θJA FOR 8-PIN SOIC, FORCED CONVECTION θJA by Velocity (Linear Feet per Minute) Single-Layer PCB, JEDEC Standard Test Boards Multi-Layer PCB, JEDEC Standard Test Boards 0 200 500 153.3°C/W 112.7°C/W 128.5°C/W 103.3°C/W 115.5°C/W 97.1°C/W NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs. 85211AMI-01 www.icst.com/products/hiperclocks.html 8 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER 3. Calculations and Equations. The purpose of this section is to derive the power dissipated into the load. HSTL output driver circuit and termination are shown in Figure 4. VDD Q1 VOUT RL 50Ω FIGURE 4. HSTL DRIVER CIRCUIT AND TERMINATION To calculate worst case power dissipation into the load, use the following equations which assume a 50Ω load. Pd_H is power dissipation when the output drives high. Pd_L is the power dissipation when the output drives low. Pd_H = (VOH_MAX /R ) * (VDD_MAX - V L ) OH_MAX Pd_L = (VOL_MAX /R ) * (VDD_MAX - VOL_MAX) L Pd_H = (1.4V/50Ω) * (3.465V - 1.4V) = 57.82mW Pd_L = (0.4V/50Ω) * (3.465V - 0.4V) = 24.52mW Total Power Dissipation per output pair = Pd_H + Pd_L = 82.34mW 85211AMI-01 www.icst.com/products/hiperclocks.html 9 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER RELIABILITY INFORMATION TABLE 7. θJAVS. AIR FLOW TABLE FOR 8 LEAD SOIC θJA by Velocity (Linear Feet per Minute) Single-Layer PCB, JEDEC Standard Test Boards Multi-Layer PCB, JEDEC Standard Test Boards 0 200 500 153.3°C/W 112.7°C/W 128.5°C/W 103.3°C/W 115.5°C/W 97.1°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 ICS85211I-01 is: 411 85211AMI-01 www.icst.com/products/hiperclocks.html 10 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER PACKAGE OUTLINE - M SUFFIX FOR 8 LEAD SOIC TABLE 8. PACKAGE DIMENSIONS SYMBOL Millimeters MINIMUN N MAXIMUM 8 A 1.35 1.75 A1 0.10 0.25 B 0.33 0.51 C 0.19 0.25 D 4.80 5.00 E 3.80 4.00 e 1.27 BASIC H 5.80 6.20 h 0.25 0.50 L 0.40 1.27 α 0° 8° Reference Document: JEDEC Publication 95, MS-012 85211AMI-01 www.icst.com/products/hiperclocks.html 11 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER TABLE 9. ORDERING INFORMATION Part/Order Number Marking Package Shipping Packaging Temperature ICS85211AMI-01 5211AI01 8 lead SOIC tube -40°C to 85°C ICS85211AMI-01T 5211AI01 8 lead SOIC 2500 tape & reel -40°C to 85°C ICS85211AMI-01LF 211AI01L 8 lead "Lead-Free" SOIC tube -40°C to 85°C ICS85211AMI-01LFT 211AI01L 8 lead "Lead-Free" SOIC 2500 tape & reel -40°C to 85°C NOTE: Par ts thar are ordered with an "LF" suffix to the par t number are the Pb-Free configuration and are RoHS compliant. The aforementioned trademark, HiPerClockS 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 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. 85211AMI-01 www.icst.com/products/hiperclocks.html 12 REV. A NOVEMBER 1, 2005 ICS85211I-01 Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-HSTL FANOUT BUFFER REVISION HISTORY SHEET Rev A Table Page 1 2 2 2 Throughout data sheet changed LVHSTL to HSTL. Changed nCLK Type from VDD/2 to Pullup/Pulldown. Pin Characteristics Table - changed CIN 4pF max. to 4pF typical. Changed RPULLUP to RPULLUP/RPULLDOWN, Pullup/Pulldown Resistors. 7/16/03 Features section - added Lead Free/RoHS bullet. Added Recommendations for Unused Output Pins. Ordering Information Table - added Lead-Free par t number and marking. 11/01/05 T9 1 7 12 A 85211AMI-01 Description of Change www.icst.com/products/hiperclocks.html 13 Date REV. A NOVEMBER 1, 2005