ASM2I9942P May 2005 rev 0.3 Low Voltage 1:18 Clock Distribution Chip Features With low output impedance (≈12Ω), in both the HIGH and LVPECL Clock Input 2.5V LVCMOS LOW logic states, the output buffers of the ASM2I9942P Outputs for Pentium IITM* With an output impedance of 12Ω, the ASM2I9942P can Microprocessor Support 200pS Maximum are ideal for driving series terminated transmission lines. Targeted Output–to–Output drive two series terminated transmission lines from each output. This capability gives the ASM2I9942P an effective Skew fanout of 1:36. The ASM2I9942P provides enough copies Maximum Output Frequency of 250MHz @3.3 VCC of low skew clocks for most high performance synchronous 32–Lead LQFP and TQFP Packaging systems. Single 3.3V or 2.5V Supply The differential LVPECL inputs of the ASM2I9942P allow Pin and Function compatible with MPC942P the device to interface directly with a LVPECL fanout buffer to build very wide clock fanout trees or to couple to a high Functional Description The ASM2I9942P is a 1:18 low voltage clock distribution chip with 2.5V or 3.3V LVCMOS output capabilities. The device is offered in two versions; the ASM2I9942C has an frequency clock source. The OE pins will place the outputs into a high impedance state. The OE pin has an internal pullup resistor. LVCMOS input clock while the ASM2I9942P has a The ASM2I9942P is a single supply device. The VCC power LVPECL input clock. The 18 outputs are 2.5V or 3.3V pins require either 2.5V or 3.3V. The 32 lead LQFP and LVCMOS compatible and feature the drive strength to drive TQFP package is chosen to optimize performance, board 50Ω series or parallel terminated transmission lines. With space and cost of the device. The 32–lead LQFP and output-to-output skews of 200pS, the ASM2I9942P is ideal TQFP have a 7x7mm2 body size with conservative 0.8mm as a clock distribution chip for the most demanding of pin spacing. synchronous systems. The 2.5V outputs also make the device ideal for supplying clocks for a high performance Pentium IITM microprocessor based design. * Pentium II is a trademark of Intel Corporation Block Diagram Table 1. Function Table Q0 PECL_CLK PECL_CLK Q1-Q16 Q17 OE Output 0 1 HIGH IMPEDANCE OUTPUTS ENABLED OE (Int. Pullup) Alliance Semiconductor 2575, Augustine Drive • Santa Clara, CA • Tel: 408.855.4900 • Fax: 408.855.4999 • www.alsc.com Notice: The information in this document is subject to change without notice. ASM2I9942P May 2005 rev 0.3 Q6 Q7 Q8 VCC Q9 Q10 Q11 GND Pin Diagram 24 23 22 21 20 19 18 17 GND 25 16 VCC Q5 26 15 Q12 Q4 27 14 Q13 Q3 28 13 Q14 VCC 29 12 GND Q2 30 11 Q15 Q1 31 10 Q16 Q0 32 9 Q17 5 NC PECL_CLK Table 2. Pin Description Pin # Pin Name 6 7 8 VCC 4 VCC 3 PECL_CLK 2 OE GND 1 GND ASM2I9942P I/O Type Function 5 6 PECL_CLK, PECL_CLK Input LVPECL LVPECL Clock Inputs 3 OE Input LVCMOS Output enable/disable (high–impedance tristate) 4 NC - 32,31,30,28,27,26,24,23,22,20,19,18,15, 14,13,11,10,9 - No connect Q0 – Q17 Output LVCMOS 1,2,12,17,25 GND Supply Ground 7,8,16,21,29 VCC Supply VCC Clock outputs Negative power supply (GND) for I/O and core. Positive power supply for I/O and core. All VCC pins must be connected to the positive power supply for correct operation Table 3. Absolute Maximum Rating1 Symbol Min Max Unit Supply Voltage –0.3 3.6 V VI Input Voltage –0.3 IIN TStor Input Current Storage Temperature Range VCC + 0.3 ±20 125 mA °C VCC Parameter –40 V Note: 1. These are stress ratings only and are not implied for functional use. Exposure to absolute maximum ratings for prolonged periods of time may affect device reliability. Low Voltage 1:18 Clock Distribution Chip Notice: The information in this document is subject to change without notice. 2 of 10 ASM2I9942P May 2005 rev 0.3 Table 4. DC Characteristics (TA = 0°to 70°C, VCC = 2.5V ± 5%) Symbol Characteristic VIH Input HIGH Voltage VIL Input LOW Voltage VPP Input Swing PECL_CLK VX Input Crosspoint PECL_CLK VOH Output HIGH Voltage VOL Output LOW Voltage IIN Input Current Min Typ 2.0 Max Unit VCC V 0.8 V 0.6 1.0 V VCC–1.0 VCC–0.6 V 2.0 V IOH = –16 mA 0.5 V IOL = 16 mA ±200 µA CIN Input Capacitance 4.0 pF CPD Power Dissipation Capacitance 14 pF ZOUT Output Impedance 12 ICC Maximum Quiescent Supply Current 0.5 Condition Per Output Ω 5.0 mA Max Unit Table 5. AC Characteristics (TA = 0°to 70°C, VCC = 2.5V ± 5%) Symbol Characteristic Min Typ Fmax Maximum Frequency 200 MHz tPLH Propagation Delay 1.8 4.0 nS tPHL Propagation Delay 2.0 4.3 nS tsk(o) Output-to-Output Skew within one bank tsk(pr) Part–to–Part Skew 1 150 2.2 pS 1.3 pS 1.0 nS Max Unit VCC V 0.8 V 0.6 1.0 V VCC–1.0 VCC–0.6 tsk(pr) tr, tf 2 Part–to–Part Skew Output Rise/Fall Time 0.1 Condition nS Note: 1. Across temperature and voltage ranges, includes output skew. 2. For a specific temperature and voltage, includes output skew. Table 6. DC Characteristics (TA = 0°to 70°C, VCC = 3.3V ± 5%) Symbol Characteristic Min Typ VIH Input HIGH Voltage VIL Input LOW Voltage 2.4 VPP Input Swing PECL.CLK VX Input Crosspoint PECL_CLK VOH Output HIGH Voltage VOL Output LOW Voltage IIN Input Current CIN Input Capacitance 4.0 pF CPD Power Dissipation Capacitance 14 pF 2.4 ZOUT Output Impedance 12 ICC Maximum Quiescent Supply Current 0.5 Condition V V IOH = –20 mA 0.6 V IOL = 20 mA ±200 µA Per Output Ω 5.0 mA Low Voltage 1:18 Clock Distribution Chip Notice: The information in this document is subject to change without notice. 3 of 10 ASM2I9942P May 2005 rev 0.3 Table 7. AC Characteristics (TA = 0°to 70°C, VCC = 3.3V ± 5%) Symbol Characteristic Min Fmax Maximum Frequency tPLH Propagation Delay 1.5 tPHL tsk(o) Propagation Delay 1.5 Typ Max Unit 250 MHz 3.2 nS 3.6 nS Output-to-output Skew within one bank 150 pS tsk(pr) 1 Part–to–Part Skew 1.7 nS tsk(pr) tr, tf Part–to–Part Skew2 1.0 pS 1.0 nS Output Rise/Fall Time 0.1 Condition Note: 1. Across temperature and voltage ranges, includes output skew. 2. For a specific temperature and voltage, includes output skew. Low Voltage 1:18 Clock Distribution Chip Notice: The information in this document is subject to change without notice. 4 of 10 ASM2I9942P May 2005 rev 0.3 per output, (Μ)ΣCL represents the external capacitive output load, N is the number of active outputs (N is always 12 in case of the ASM2I9942P). The ASM2I9942P supports driving transmission lines to maintain high signal integrity and tight timing parameters. Any transmission line will hide the lumped capacitive load at the end of the board trace, therefore, ΣCL is zero for controlled transmission line systems and can be eliminated from equation 1. Using parallel termination output termination results in equation 2 for power dissipation. Power Consumption of the ASM2I9942P and Thermal Management The ASM2I9942P AC specification is guaranteed for the entire operating frequency range up to 250MHz. The ASM2I9942P power consumption and the associated long-term reliability may decrease the maximum frequency limit, depending on operating conditions such as clock frequency, supply voltage, output loading, ambient temperature, vertical convection and thermal conductivity of package and board. This section describes the impact of these parameters on the junction temperature and gives a guideline to estimate the ASM2I9942P die junction temperature and the associated device reliability. In equation 2, P stands for the number of outputs with a parallel or thevenin termination, VOL, IOL, VOH and IOH are a function of the output termination technique and DCQ is the clock signal duty cycle. If transmission lines are used ΣCL is zero in equation 2 and can be eliminated. In general, the use of controlled transmission line techniques eliminates the impact of the lumped capacitive loads at the end lines and greatly reduces the power dissipation of the device. Equation 3 describes the die junction temperature TJ as a function of the power consumption. Table 8. Die junction temperature and MTBF Junction temperature (°C) MTBF (Years) 100 20.4 110 9.1 120 4.2 130 2.0 Increased power consumption will increase the die junction temperature and impact the device reliability (MTBF). According to the system-defined tolerable MTBF, the die junction temperature of the ASM2I9942P needs to be controlled and the thermal impedance of the board/package should be optimized.The power dissipated in the ASM2I9942P is represented in equation 1. Where ICCQ is the static current consumption of the ASM2I9942P, CPD is the power dissipation capacitance Where Rthja is the thermal impedance of the package (junction to ambient) and TA is the ambient temperature. According to Table 8, the junction temperature can be used to estimate the long-term device reliability. Further, combining equation 1 and equation 2 results in a maximum operating frequency for the ASM2I9942P in a series terminated transmission line system, equation 4. PTOT = I CCQ + VCC ⋅ f CLOCK ⋅ N ⋅ C PD + ∑ C L ⋅ VCC M PTOT = VCC ⋅ I CCQ + VCC ⋅ f CLOCK ⋅ N ⋅ C PD + ∑ C L + ∑ DC Q ⋅ I OH (VCC − VOH ) + (1 − DC Q ) ⋅ I OL ⋅ VOL M P T J = T A + PTOT ⋅ Rthja [ f CLOCKMAX = C PD 1 2 ⋅ N ⋅ VCC T − TA ⋅ JMAX − (I CCQ ⋅ VCC ) Rthja Low Voltage 1:18 Clock Distribution Chip Notice: The information in this document is subject to change without notice. Equation 1 ] Equation 2 Equation 3 Equation 4 5 of 10 ASM2I9942P May 2005 rev 0.3 TJ,MAX should be selected according to the MTBF system requirements and Table 8. Rthja can be derived from Table 9. The Rthja represent data based on 1S2P boards, using 2S2P boards will result in lower thermal impedance than indicated below. Table 9. Thermal package impedance of the 32LQFP Convection, Rthja (1P2S Rthja (2P2S board), °C/W board), °C/W LFPM Still air 100 lfpm 200 lfpm 300 lfpm 400 lfpm 500 lfpm 86 76 71 68 66 60 61 56 54 53 52 49 If the calculated maximum frequency is below 350 MHz, it becomes the upper clock speed limit for the given application conditions. The following eight derating charts describe the safe frequency operation range for the ASM2I9942P. The charts were calculated for a maximum tolerable die junction temperature of 110°C (120°C), corresponding to an estimated MTBF of 9.1 years (4 years), a supply voltage of 3.3V and series terminated transmission line or capacitive loading. Depending on a given set of these operating conditions and the available device convection a decision on the maximum operating frequency can be made. Low Voltage 1:18 Clock Distribution Chip Notice: The information in this document is subject to change without notice. 6 of 10 ASM2I9942P May 2005 rev 0.3 Package Information 32-lead TQFP Package SECTION A-A Dimensions Symbol Inches Min Max Millimeters Min Max A …. 0.0472 … 1.2 A1 0.0020 0.0059 0.05 0.15 A2 0.0374 0.0413 0.95 1.05 D 0.3465 0.3622 8.8 9.2 D1 0.2717 0.2795 6.9 7.1 E 0.3465 0.3622 8.8 9.2 E1 0.2717 0.2795 6.9 7.1 L 0.0177 0.0295 0.45 0.75 L1 0.03937 REF 1.00 REF T 0.0035 0.0079 0.09 0.2 T1 0.0038 0.0062 0.097 0.157 b 0.0118 0.0177 0.30 0.45 b1 0.0118 0.0157 0.30 0.40 R0 0.0031 0.0079 0.08 0.2 a 0° 7° 0° 7° e 0.031 BASE 0.8 BASE Low Voltage 1:18 Clock Distribution Chip Notice: The information in this document is subject to change without notice. 7 of 10 ASM2I9942P May 2005 rev 0.3 32-lead LQFP Package SECTION A-A Dimensions Symbol Inches Min Max Millimeters Min Max A …. 0.0630 … 1.6 A1 0.0020 0.0059 0.05 0.15 A2 0.0531 0.0571 1.35 1.45 D 0.3465 0.3622 8.8 9.2 D1 0.2717 0.2795 6.9 7.1 E 0.3465 0.3622 8.8 9.2 E1 0.2717 0.2795 6.9 7.1 L 0.0177 0.0295 0.45 0.75 L1 0.03937 REF 1.00 REF T 0.0035 0.0079 0.09 0.2 T1 0.0038 0.0062 0.097 0.157 b 0.0118 0.0177 0.30 0.45 b1 0.0118 0.0157 0.30 0.40 R0 0.0031 0.0079 0.08 0.20 e a 0.031 BASE 0° 7° 0.8 BASE 0° 7° Low Voltage 1:18 Clock Distribution Chip Notice: The information in this document is subject to change without notice. 8 of 10 ASM2I9942P May 2005 rev 0.3 Ordering Information Marking Ordering Code Package Type Operating Range ASM2I9942P-32-LT ASM2I9942PL 32-pin LQFP, Tray Industrial ASM2I9942P-32-LR ASM2I9942PL 32-pin LQFP,Tape and Reel Industrial ASM2I9942PG-32-LT ASM2I9942PGL 32-pin LQFP, Tray, Green Industrial ASM2I9942PG-32-LR ASM2I9942PGL 32-pin LQFP,Tape and Reel, Green Industrial ASM2I9942P-32-ET ASM2I9942PE 32-pin TQFP, Tray Industrial ASM2I9942P-32-ER ASM2I9942PE 32-pin TQFP,Tape and Reel Industrial ASM2I9942PG-32-ET ASM2I9942PGE 32-pin TQFP, Green Industrial ASM2I9942PG-32-ER ASM2I9942PGE 32-pin TQFP,Tape and Reel, Green Industrial Device Ordering Information A S M 2 I 9 9 4 2 P G - 3 2 - L R R = Tape & reel, T = Tube or Tray O = SOT S = SOIC T = TSSOP A = SSOP V = TVSOP B = BGA Q = QFN U = MSOP E = TQFP L = LQFP U = MSOP P = PDIP D = QSOP X = SC-70 DEVICE PIN COUNT F = LEAD FREE AND RoHS COMPLIANT PART G = GREEN PACKAGE PART NUMBER X= Automotive I= Industrial P or n/c = Commercial (-40C to +125C) (-40C to +85C) (0C to +70C) 1 = Reserved 2 = Non PLL based 3 = EMI Reduction 4 = DDR support products 5 = STD Zero Delay Buffer 6 = Power Management 7 = Power Management 8 = Power Management 9 = Hi Performance 0 = Reserved ALLIANCE SEMICONDUCTOR MIXED SIGNAL PRODUCT Licensed under US patent #5,488,627, #6,646,463 and #5,631,920. Low Voltage 1:18 Clock Distribution Chip Notice: The information in this document is subject to change without notice. 9 of 10 ASM2I9942P May 2005 rev 0.3 Alliance Semiconductor Corporation 2575, Augustine Drive, Santa Clara, CA 95054 Tel# 408-855-4900 Fax: 408-855-4999 www.alsc.com Copyright © Alliance Semiconductor All Rights Reserved Part Number: ASM2I9942P Document Version: 0.3 Note: This product utilizes US Patent # 6,646,463 Impedance Emulator Patent issued to Alliance Semiconductor, dated 11-11-2003 © Copyright 2003 Alliance Semiconductor Corporation. All rights reserved. Our three-point logo, our name and Intelliwatt are trademarks or registered trademarks of Alliance. All other brand and product names may be the trademarks of their respective companies. Alliance reserves the right to make changes to this document and its products at any time without notice. Alliance assumes no responsibility for any errors that may appear in this document. The data contained herein represents Alliance's best data and/or estimates at the time of issuance. Alliance reserves the right to change or correct this data at any time, without notice. If the product described herein is under development, significant changes to these specifications are possible. The information in this product data sheet is intended to be general descriptive information for potential customers and users, and is not intended to operate as, or provide, any guarantee or warrantee to any user or customer. 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Alliance does not authorize its products for use as critical components in life-supporting systems where a malfunction or failure may reasonably be expected to result in significant injury to the user, and the inclusion of Alliance products in such life-supporting systems implies that the manufacturer assumes all risk of such use and agrees to indemnify Alliance against all claims arising from such use. Low Voltage 1:18 Clock Distribution Chip Notice: The information in this document is subject to change without notice. 10 of 10