Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER GENERAL DESCRIPTION FEATURES The ICS853111A is a low skew, high performance 1-to-10 Differential-to-2.5V/3.3V LVPECL/ HiPerClockS™ ECL Fanout Buffer and a member of the HiPerClockS ™ family of High Performance Clock Solutions from ICS. The ICS853111A is characterized to operate from either a 2.5V, 3.3V or a 5V power supply. Guaranteed output and par t-to-par t skew characteristics make the ICS853111A ideal for those clock distribution applications demanding well defined performance and repeatability. • 10 differential 2.5V/3.3V LVPECL / ECL outputs ICS • 2 selectable differential input pairs • PCLKx, nPCLKx pairs can accept the following differential input levels: LVPECL, LVDS, CML, SSTL • Maximum output frequency: >3GHz • Translates any single ended input signal to 3.3V LVPECL levels with resistor bias on nPCLK input • Output skew: 23ps (typical) • Part-to-part skew: 85ps (typical) • Propagation delay: 705ps (typical) • Jitter, RMS: < 0.03ps (typical) • LVPECL mode operating voltage supply range: VCC = 2.375V to 5.25V, VEE = 0V • ECL mode operating voltage supply range: VCC = 0V, VEE = -5.25V to -2.375V • -40°C to 85°C ambient operating temperature • Pin compatible with MC100EP111 and MC100LVEP111 Q1 nQ1 nQ6 Q6 nQ5 VCCO 26 15 Q7 Q2 27 14 nQ7 Q3 nQ3 nQ1 28 13 Q8 Q1 29 12 nQ8 Q4 nQ4 nQ0 30 11 Q9 Q0 31 10 nQ9 Q5 nQ5 VCCO 32 9 VCCO 1 2 3 4 5 6 7 8 PCLK1 nPCLK1 VEE Q7 nQ7 ICS853111A VBB Q6 nQ6 32-Lead LQFP 7mm x 7mm x 1.4mm package body Y Package Top View Q8 nQ8 Q9 nQ9 853111AY Q5 16 nQ2 nPCLK0 V BB nQ4 25 Q2 nQ2 CLK_SEL Q4 24 23 22 21 20 19 18 17 VCCO PCLK0 1 Q3 PCLK1 nPCLK1 Q0 nQ0 VCC 0 CLK_SEL PCLK0 nPCLK0 PIN ASSIGNMENT nQ3 BLOCK DIAGRAM www.icst.com/products/hiperclocks.html 1 REV. B MAY 14, 2004 ICS853111A Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER TABLE 1. PIN DESCRIPTIONS Number Name 1 VCC Power Type Description 2 CLK_SEL Input Pulldown 3 PCLK0 Input Pulldown 4 nPCLK0 Input Pullup/Pulldown 5 VBB Output 6 PCLK1 Input Pulldown 7 nPCLK1 Input Pullup/Pulldown 8 V EE Power Core supply pin. Clock select input. When HIGH, selects PCLK1, nPCLK1 inputs. When LOW, selects PCLK0, nPCLK0 inputs. LVCMOS / LVTTL interface levels. Non-inver ting differential clock input. Inver ting differential LVPECL clock input. VCC/2 default when left floating. Bias voltage. Non-inver ting differential clock input. Inver ting differential LVPECL clock input. VCC/2 default when left floating. Negative supply pin. 9, 16, 25, 32 VCCO Power Output supply pins. 10, 11 nQ9, Q9 Output Differential output pair. LVPECL interface levels. 1 2, 13 nQ8, Q8 Output Differential output pair. LVPECL interface levels. 14, 15 nQ7, Q7 Output Differential output pair. LVPECL interface levels. 17, 18 nQ6, Q6 Output Differential output pair. LVPECL interface levels. 19, 20 nQ5, Q5 Output Differential output pair. LVPECL interface levels. 21, 22 nQ4, Q4 Output Differential output pair. LVPECL interface levels. 23, 24 nQ3, Q3 Output Differential output pair. LVPECL interface levels. 26, 27 nQ2, Q2 Output Differential output pair. LVPECL interface levels. 28, 29 nQ1, Q1 Output Differential output pair. LVPECL interface levels. 30, 31 nQ0, Q0 Output Differential output pair. LVPECL interface levels. NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values. TABLE 2. PIN CHARACTERISTICS Symbol Parameter Test Conditions Minimum RPULLDOWN Input Pulldown Resistor 75 KΩ RVCC/2 Pullup/Pulldown Resistors 50 KΩ PCLKx Outputs nPCLKx Q0:Q9 nQ0:Q9 Maximum Units TABLE 3B. CONTROL INPUT FUNCTION TABLE TABLE 3A. CLOCK INPUT FUNCTION TABLE Inputs Typical Input to Output Mode Polarity Inputs 0 1 LOW HIGH Differential to Differential Non Inver ting CLK_SEL 1 0 Biased; NOTE 1 Biased; NOTE 1 HIGH LOW Differential to Differential Non Inver ting 0 PCLK0, nPCLK0 LOW HIGH Single Ended to Differential Non Inver ting 1 PCLK1, nPCLK1 HIGH LOW Single Ended to Differential Non Inver ting 0 1 Selected Source Biased; 0 HIGH LOW Single Ended to Differential Inver ting NOTE 1 Biased; 1 LOW HIGH Single Ended to Differential Inver ting NOTE 1 NOTE 1: Please refer to the Application Information, "Wiring the Differential Input to Accept Single Ended Levels". 853111AY www.icst.com/products/hiperclocks.html 2 REV. B MAY 14, 2004 Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC 6V (LVPECL mode, VEE = 0) Negative Supply Voltage, VEE -6V (ECL mode, VCC = 0) Inputs, VI (LVPECL mode) -0.5V to VCC + 0.5 V Inputs, VI (ECL mode) 0.5V to VEE - 0.5V Outputs, IO Continuous Current Surge Current VBB Sink/Source, IBB 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 Character- 50mA 100mA istics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability. ± 0.5mA Operating Temperature Range, TA -40°C to +85°C Storage Temperature, TSTG -65°C to 150°C Package Thermal Impedance, θJA 37.8°C/W (0 lfpm) (Junction-to-Ambient) TABLE 4A. POWER SUPPLY DC CHARACTERISTICS, VCC = 2.375V TO 3.8V; VEE = 0V Symbol Parameter VCC Positive Supply Voltage IEE Power Supply Current Test Conditions Minimum Typical Maximum Units 2.375 3.3 5.25 V 85 mA TABLE 4B. LVPECL DC CHARACTERISTICS, VCC = 3.3V; VEE = 0V Symbol Parameter Min -40°C Typ Max Min 25°C Typ Max Min 85°C Typ Max Units VOH Output High Voltage; NOTE 1 2.175 2.275 2.38 2.225 2.295 2.37 2.295 2.33 2.365 V VOL Output Low Voltage; NOTE 1 1.405 1.545 1.68 1.425 1.52 1.615 1.44 1.535 1.63 V VIH Input High Voltage(Single-Ended) 2.075 2.36 2.075 2.36 2.075 2.36 V VIL Input Low Voltage(Single-Ended) 1.43 1.765 1.43 1.765 1.43 1.765 V VBB Output Voltage Reference; NOTE 2 1.86 1.98 1.86 1.98 1.86 1.98 V VPP Peak-to-Peak Input Voltage Input High Voltage Common Mode Range; NOTE 3, 4 Input PCLK0, PCLK1 High Current nPCLK0, nPCLK1 PCLK0, PCLK1 Input Low Current nPCLK0, nPCLK1 150 1200 150 1200 150 1200 mV 3.3 1.2 3.3 1.2 3.3 V 150 µA VCMR IIH IIL 800 1.2 800 150 800 150 -10 -10 -10 µA -150 -150 -150 µA Input and output parameters vary 1:1 with VCC. VEE can vary +0.925V to -0.5V. NOTE 1: Outputs terminated with 50Ω to VCCO - 2V. NOTE 2: Single-ended input operation is limited. VCC ≥ 3V in LVPECL mode. NOTE 3: Common mode voltage is defined as VIH. NOTE 4: For single-ended applications, the maximum input voltage for PCLK0, nPCLK0 and PCLK1, nPCLK1 is VCC + 0.3V. 853111AY www.icst.com/products/hiperclocks.html 3 REV. B MAY 14, 2004 Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER TABLE 4C. LVPECL DC CHARACTERISTICS, VCC = 2.5V; VEE = 0V Symbol Parameter VOH -40°C 25°C 85°C Units Min Typ Max Min Typ Max Min Typ Max Output High Voltage; NOTE 1 1.375 1.475 1.58 1.425 1.495 1.57 1.495 1.53 1.565 VOL Output Low Voltage; NOTE 1 0.605 0.745 0.88 0.625 0.72 0.815 0.64 0.735 0.83 V VIH Input High Voltage(Single-Ended) 1.275 1.56 1.275 1.56 1.275 -0.83 V VIL Input Low Voltage(Single-Ended) 0.63 0.965 0.63 0.965 0.63 0.965 V VPP 150 1200 150 1200 150 1200 mV 2.5 1.2 2.5 1.2 2.5 V IIH Peak-to-Peak Input Voltage Input High Voltage Common Mode Range; NOTE 2, 3 Input PCLK0, PCLK1 High Current nPCLK0, nPCLK1 150 µA IIL Input Low Current VCMR PCLK0, PCLK1 800 1.2 800 150 -10 800 150 -10 -10 V µA -150 -150 -150 nPCLK0, nPCLK1 Input and output parameters vary 1:1 with VCC. VEE can vary +0.925V to -0.5V. NOTE 1: Outputs terminated with 50Ω to VCCO - 2V. NOTE 2: Common mode voltage is defined as VIH. NOTE 3: For single-ended applications, the maximum input voltage for PCLK0, nPCLK0 and PCLK1, nPCLK1 is VCC + 0.3V. µA TABLE 4D. LVPECL DC CHARACTERISTICS, VCC = 5V; VEE = 0V Min -40°C Typ Max Min 25°C Typ Max Min 85°C Typ Max Output High Voltage; NOTE 1 3.875 3.975 4.08 3.925 3.995 4.07 3.995 4.03 4.065 VOL Output Low Voltage; NOTE 1 3.105 3.245 3.38 3.125 3.22 3.315 3.14 3.235 3.33 V VIH Input High Voltage(Single-Ended) 3.775 4.06 3.775 4.06 3.775 4.06 V VIL Input Low Voltage(Single-Ended) 3.13 3.465 3.13 3.465 3.13 3.465 V VBB Output Voltage Reference; NOTE 2 3.56 3.68 3.56 3.68 3.56 3.68 V VPP Peak-to-Peak Input Voltage Input High Voltage Common Mode Range; NOTE 3, 4 Input PCLK0, PCLK1 High Current nPCLK0, nPCLK1 PCLK0, PCLK1 Input Low Current nPCLK0, nPCLK1 150 1200 150 1200 150 1200 mV 5 1.2 5 1.2 5 V 150 µA Symbol Parameter VOH VCMR IIH IIL 800 1.2 800 150 -10 800 150 -10 -10 www.icst.com/products/hiperclocks.html 4 V µA -150 -150 -150 Input and output parameters vary 1:1 with VCC. VEE can vary +0.925V to -0.5V. NOTE 1: Outputs terminated with 50Ω to VCCO - 2V. NOTE 2: Single-ended input operation is limited. VCC ≥ 3V in LVPECL mode. NOTE 3: Common mode voltage is defined as VIH. NOTE 4: For single-ended applications, the maximum input voltage for PCLK0, nPCLK0 and PCLK1, nPCLK1 is VCC + 0.3V. 853111AY Units µA REV. B MAY 14, 2004 Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER TABLE 4C. ECL DC CHARACTERISTICS, VCC = 0V; VEE = -5.25V TO -2.375V Symbol Parameter VOH -40°C 25°C 85°C Units Min Typ Max Min Typ Max Min Typ Max Output High Voltage; NOTE 1 -1.125 -1.025 -0.92 -1.075 -1.005 -0.93 -1.005 -0.97 -0.935 V VOL Output Low Voltage; NOTE 1 -1.895 -1.755 -1.62 -1.875 -1.78 -1.685 -1.86 -1.765 -1.67 V VIH Input High Voltage(Single-Ended) -1.225 -0.94 -1.225 -0.94 -1.225 -0.94 V VIL Input Low Voltage(Single-Ended) -1.87 -1.535 -1.87 -1.535 -1.87 -1.535 V VBB Output Voltage Reference; NOTE 2 -1.44 -1.32 -1.44 -1.32 -1.44 VPP 150 1200 150 1200 150 0 VEE+1.2V 0 VEE+1.2V IIH Peak-to-Peak Input Voltage Input High Voltage Common Mode Range; NOTE 3, 4 Input PCLK0, PCLK1 High Current nPCLK0, nPCLK1 IIL Input Low Current VCMR 800 VEE+1.2V PCLK0, PCLK1 800 150 800 150 -10 -10 -1.32 V 1200 mV 0 V 150 µA -10 µA -150 -150 -150 nPCLK0, nPCLK1 Input and output parameters vary 1:1 with VCC. VEE can vary +0.925V to -0.5V. NOTE 1: Outputs terminated with 50Ω to VCCO - 2V. NOTE 2: Single-ended input operation is limited. VCC ≥ 3V in LVPECL mode. NOTE 3: Common mode voltage is defined as VIH. NOTE 4: For single-ended applications, the maximum input voltage for PCLK0, nPCLK0 and PCLK1, nPCLK1 is VCC + 0.3V. µA TABLE 5. AC CHARACTERISTICS, VCC = 0V; VEE = -5.25V TO -2.375V OR VCC = 2.375V TO 5.25V; VEE = 0V -40°C Symbol Parameter fMAX Output Frequency t PD Propagation Delay; NOTE 1 Min Typ 25°C Max Min >3 570 670 Typ 85°C Max Min >3 770 605 705 Typ Max >3 805 665 765 Units GHz 875 ps tsk(o) Output Skew; NOTE 2, 4 23 35 23 35 23 35 ps tsk(pp) Par t-to-Par t Skew; NOTE 3, 4 Buffer Additive Phase Jitter, RMS; refer to Additive Phase Jitter section 85 150 85 150 85 150 ps tjit tR/tF Output Rise/Fall Time 20% to 80% 0.03 85 200 0.03 315 100 200 0.03 285 85 200 ps 315 ps All parameters are measured ≤ 1GHz unless otherwise noted. 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 the 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. 853111AY www.icst.com/products/hiperclocks.html 5 REV. B MAY 14, 2004 ICS853111A Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER ADDITIVE PHASE JITTER the 1Hz band to the power in the fundamental. When the required offset is specified, the phase noise is called a dBc value, which simply means dBm at a specified offset from the fundamental. By investigating jitter in the frequency domain, we get a better understanding of its effects on the desired application over the entire time record of the signal. It is mathematically possible to calculate an expected bit error rate given a phase noise plot. The spectral purity in a band at a specific offset from the fundamental compared to the power of the fundamental is called the dBc Phase Noise. This value is normally expressed using a Phase noise plot and is most often the specified plot in many applications. Phase noise is defined as the ratio of the noise power present in a 1Hz band at a specified offset from the fundamental frequency to the power value of the fundamental. This ratio is expressed in decibels (dBm) or a ratio of the power in 0 -10 -20 Input/Output Additive Phase Jitter at 155.52MHz -30 = 0.03ps (typical) -40 SSB PHASE NOISE dBc/HZ -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 -150 -160 -170 -180 -190 1k 10k 100k 1M 10M 100M OFFSET FROM CARRIER FREQUENCY (HZ) As with most timing specifications, phase noise measurements have issues. The primary issue relates to the limitations of the equipment. Often the noise floor of the equipment is higher than the noise floor of the device. This is illustrated above. The de- 853111AY vice meets the noise floor of what is shown, but can actually be lower. The phase noise is dependant on the input source and measurement equipment. www.icst.com/products/hiperclocks.html 6 REV. B MAY 14, 2004 Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER PARAMETER MEASUREMENT INFORMATION 2V VCC, VCCO Qx VCC SCOPE nPCLK0, nPCLK1 LVPECL V PP nQx VEE Cross Points V CMR PCLK0, PCLK1 V EE -3.25V to -0.375V OUTPUT LOAD AC TEST CIRCUIT DIFFERENTIAL INPUT LEVEL nQx PART 1 Qx nQx nQy nQy Qx PART 2 Qy Qy t sk(pp) t sk(o) PART-TO-PART SKEW OUTPUT SKEW 80% nPCLK0, nPCLK1 80% PCLK0, PCLK1 VSW I N G Clock Outputs 20% 20% tR nQ0:nQ9 tF Q0:Q9 tPD OUTPUT RISE/FALL TIME 853111AY PROPAGATION DELAY www.icst.com/products/hiperclocks.html 7 REV. B MAY 14, 2004 Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER APPLICATION INFORMATION WIRING THE DIFFERENTIAL INPUT TO ACCEPT SINGLE ENDED LVCMOS LEVELS Figure 2A shows an example of the differential input that can be wired to accept single ended LVCMOS levels. The reference voltage level VBB generated from the device is connected to the negative input. The C1 capacitor should be located as close as possible to the input pin. VCC R1 1K Single Ended Clock Input PCLK V_REF nPCLK C1 0.1u R2 1K FIGURE 2A. SINGLE ENDED LVCMOS SIGNAL DRIVING DIFFERENTIAL INPUT WIRING THE DIFFERENTIAL INPUT TO ACCEPT SINGLE ENDED LVPECL LEVELS Figure 2B shows an example of the differential input that can be wired to accept single ended LVPECL levels. The reference voltage level VBB generated from the device is connected to the negative input. The C1 capacitor should be located as close as possible to the input pin. VDD(or VCC) CLK_IN + VBB - C1 0.1uF FIGURE 2B. SINGLE ENDED LVPECL SIGNAL DRIVING DIFFERENTIAL INPUT 853111AY www.icst.com/products/hiperclocks.html 8 REV. B MAY 14, 2004 ICS853111A Integrated Circuit Systems, Inc. TERMINATION FOR LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER 3.3V 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. 50Ω transmission lines. Matched impedance techniques should be used to maximize operating frequency and minimize signal distortion. Figures 3A and 3B 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. 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 = 50Ω 125Ω FOUT FIN Zo = 50Ω Zo = 50Ω FOUT 50Ω RTT = 1 Z ((VOH + VOL) / (VCC – 2)) – 2 o FIN 50Ω Zo = 50Ω VCC - 2V RTT 84Ω FIGURE 3A. LVPECL OUTPUT TERMINATION 853111AY 125Ω 84Ω FIGURE 3B. LVPECL OUTPUT TERMINATION www.icst.com/products/hiperclocks.html 9 REV. B MAY 14, 2004 Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER TERMINATION FOR 2.5V LVPECL OUTPUT Figure 4A and Figure 4B show examples of termination for 2.5V LVPECL driver. These terminations are equivalent to terminating 50Ω to VCC - 2V. For VCC = 2.5V, the VCC - 2V is very close to ground level. The R3 in Figure 4B can be eliminated and the termination is shown in Figure 4C. 2.5V 2.5V 2.5V VCCO=2.5V VCCO=2.5V R1 250 R3 250 Zo = 50 Ohm Zo = 50 Ohm + + Zo = 50 Ohm Zo = 50 Ohm - - 2,5V LVPECL Driv er 2,5V LVPECL Driv er R2 62.5 R1 50 R4 62.5 R2 50 R3 18 FIGURE 4B. 2.5V LVPECL DRIVER TERMINATION EXAMPLE FIGURE 4A. 2.5V LVPECL DRIVER TERMINATION EXAMPLE 2.5V VCCO=2.5V Zo = 50 Ohm + Zo = 50 Ohm 2,5V LVPECL Driv er R1 50 R2 50 FIGURE 4C. 2.5V LVPECL TERMINATION EXAMPLE 853111AY www.icst.com/products/hiperclocks.html 10 REV. B MAY 14, 2004 ICS853111A Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER LVPECL CLOCK INPUT INTERFACE here are examples only. If the driver is from another vendor, use their termination recommendation. Please consult with the vendor of the driver component to confirm the driver termination requirements. The PCLK /nPCLK accepts LVPECL, CML, SSTL and other differential signals. Both VSWING and VOH must meet the VPP and VCMR input requirements. Figures 5A to 5F show interface examples for the HiPerClockS PCLK/nPCLK input driven by the most common driver types. The input interfaces suggested 3.3V 3.3V R1 50 CML 3.3V 3.3V 3.3V Zo = 50 Ohm R2 50 Zo = 50 Ohm PCLK nPCLK PCLK R1 100 Zo = 50 Ohm nPCLK Zo = 50 Ohm HiPerClockS PCLK/nPCLK HiPerClockS PCLK/nPCLK CML Built-In Pullup FIGURE 5A. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN BY AN OPEN COLLECTOR CML DRIVER FIGURE 5B. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN BY A BUILT-IN PULLUP CML DRIVER 3.3V 3.3V 3.3V 3.3V 3.3V R3 125 3.3V R4 125 Zo = 50 Ohm 3.3V LVPECL Zo = 50 Ohm C1 Zo = 50 Ohm C2 R3 84 R4 84 PCLK PCLK Zo = 50 Ohm nPCLK LVPECL R1 84 nPCLK HiPerClockS Input R5 100 - 200 R2 84 FIGURE 5C. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN BY A 3.3V LVPECL DRIVER R6 100 - 200 R1 125 FIGURE 5D. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN BY A 3.3V LVPECL DRIVER WITH AC COUPLE 3.3V 2.5V 3.3V 3.3V 3.3V 2.5V R3 120 SSTL Zo = 50 Ohm R4 120 C1 LVDS Zo = 60 Ohm R3 1K R4 1K PCLK PCLK R5 100 Zo = 60 Ohm nPCLK R1 120 C2 nPCLK Zo = 50 Ohm HiPerClockS PCLK/nPCLK R1 1K R2 120 FIGURE 5E. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN BY AN SSTL DRIVER 853111AY HiPerClockS PCLK/nPCLK R2 125 HiPerClockS PCL K/n PC LK R2 1K FIGURE 5F. HIPERCLOCKS PCLK/nPCLK INPUT DRIVEN BY A 3.3V LVDS DRIVER www.icst.com/products/hiperclocks.html 11 REV. B MAY 14, 2004 ICS853111A Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER SCHEMATIC EXAMPLE This application note provides general design guide using ICS853111A LVPECL buffer. Figure 6 shows a schematic example of the ICS853111A LVPECL clock buffer. In this example, the input is driven by an LVPECL driver. CLK_SEL is set at logic low to select PCLK0/nPCLK0 input. Zo = 50 + Zo = 50 R2 50 VCC 32 31 30 29 28 27 26 25 C6 (Option) 0.1u 1 2 3 4 5 6 7 8 Zo = 50 Ohm Zo = 50 Ohm R4 1K R10 50 C8 (Option) 0.1u R11 50 9 10 11 12 13 14 15 16 R9 50 VCC CLK_SEL PCLK0 nPCLK0 VBB PCLK1 nPCLK1 VEE Q3 nQ3 Q4 nQ4 Q5 nQ5 Q6 nQ6 VCCO nQ9 Q9 nQ8 Q8 nQ7 Q7 VCCO 3.3V LVPECL VCCO Q0 nQ0 Q1 nQ1 Q2 nQ2 VCCO VCC - R1 50 R3 50 24 23 22 21 20 19 18 17 U1 ICS853111 VCC Zo = 50 + VCC=3.3V Zo = 50 (U1-9) VCC (U1-16) (U1-25) (U1-32) - (U1-1) R8 50 C1 0.1uF C2 0.1uF C3 0.1uF C4 0.1uF R7 50 C5 0.1uF C7 (Option) 0.1u R13 50 FIGURE 6. EXAMPLE ICS853111A LVPECL CLOCK OUTPUT BUFFER SCHEMATIC 853111AY www.icst.com/products/hiperclocks.html 12 REV. B MAY 14, 2004 Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER POWER CONSIDERATIONS This section provides information on power dissipation and junction temperature for the ICS853111A. Equations and example calculations are also provided. 1. Power Dissipation. The total power dissipation for the ICS853111A is the sum of the core power plus the power dissipated in the load(s). The following is the power dissipation for VCC = 5.25V, 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 = 5.25V * 85mA = 446.3mW Power (outputs)MAX = 30.94mW/Loaded Output pair If all outputs are loaded, the total power is 10 * 30.94mW = 309.4mW Total Power_MAX (3.8V, with all outputs switching) = 446.3mW + 309.4mW = 755.7mW 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 42.1°C/W per Table 6 below. Therefore, Tj for an ambient temperature of 85°C with all outputs switching is: 85°C + 0.756W * 42.1°C/W = 116.8°C. This is 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 32-PIN LQFP, FORCED CONVECTION θ by Velocity (Linear Feet per Minute) JA Single-Layer PCB, JEDEC Standard Test Boards Multi-Layer PCB, JEDEC Standard Test Boards 0 200 500 67.8°C/W 47.9°C/W 55.9°C/W 42.1°C/W 50.1°C/W 39.4°C/W NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs. 853111AY www.icst.com/products/hiperclocks.html 13 REV. B MAY 14, 2004 ICS853111A Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER 3. Calculations and Equations. LVPECL output driver circuit and termination are shown in Figure 7. VCCO Q1 VOUT RL 50 VCCO - 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. CCO • For logic high, VOUT = V OH_MAX (V CC_MAX • -V OH_MAX OL_MAX -V Pd_H = [(V – (V CCO_MAX OH_MAX CCO_MAX – 0.935V ) = 0.935V For logic low, VOUT = V (V =V OL_MAX =V CCO_MAX – 1.67V ) = 1.67V CCO_MAX - 2V))/R ] * (V CCO_MAX L -V OH_MAX ) = [(2V - (V CCO_MAX -V OH_MAX ))/R ] * (V CCO _MAX L -V OH_MAX )= [(2V - 0.935V)/50Ω] * 0.935V = 19.92mW Pd_L = [(V OL_MAX – (V CCO_MAX - 2V))/R ] * (V L CCO_MAX -V OL_MAX ) = [(2V - (V CCO_MAX -V OL_MAX ))/R ] * (V L CCO_MAX -V OL_MAX )= [(2V - 1.67V)/50Ω] * 1.67V = 11.02mW Total Power Dissipation per output pair = Pd_H + Pd_L = 30.94mW 853111AY www.icst.com/products/hiperclocks.html 14 REV. B MAY 14, 2004 Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER RELIABILITY INFORMATION TABLE 7. θJAVS. AIR FLOW TABLE FOR 32 LEAD LQFP θ by Velocity (Linear Feet per Minute) JA Single-Layer PCB, JEDEC Standard Test Boards Multi-Layer PCB, JEDEC Standard Test Boards 0 200 500 67.8°C/W 47.9°C/W 55.9°C/W 42.1°C/W 50.1°C/W 39.4°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 ICS853111A is: 1340 853111AY www.icst.com/products/hiperclocks.html 15 REV. B MAY 14, 2004 ICS853111A Integrated Circuit Systems, Inc. PACKAGE OUTLINE - Y SUFFIX LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER FOR 32 LEAD LQFP TABLE 8. PACKAGE DIMENSIONS JEDEC VARIATION ALL DIMENSIONS IN MILLIMETERS BBA SYMBOL MINIMUM NOMINAL MAXIMUM 32 N A -- -- 1.60 A1 0.05 -- 0.15 A2 1.35 1.40 1.45 b 0.30 0.37 0.45 c 0.09 -- 0.20 D 9.00 BASIC D1 7.00 BASIC D2 5.60 Ref. E 9.00 BASIC E1 7.00 BASIC E2 5.60 Ref. 0.80 BASIC e L 0.45 0.60 0.75 θ 0° -- 7° ccc -- -- 0.10 Reference Document: JEDEC Publication 95, MS-026 853111AY www.icst.com/products/hiperclocks.html 16 REV. B MAY 14, 2004 ICS853111A Integrated Circuit Systems, Inc. LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER TABLE 9. ORDERING INFORMATION Part/Order Number Marking Package Count Temperature ICS853111AY ICS853111AY 32 lead LQFP 250 per tray -40°C to 85°C ICS853111AYT ICS853111AY 32 lead LQFP on Tape and Reel 1000 -40°C to 85°C 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. 853111AY www.icst.com/products/hiperclocks.html 17 REV. B MAY 14, 2004 Integrated Circuit Systems, Inc. ICS853111A LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER REVISION HISTORY SHEET Rev Table A T4A T4D T5 B Page 11 13 & 14 1 3 4 5 7 11 13 & 14 B 853111AY 3 Description of Change Corrected Figure 5C. Power Considerations - corrected Power(outputs)MAX from 30.2mW to 30.94mW, and revised Junction Temperature and Worse Case Power Dissipation equations. Features section - increased voltage range to 5.25V. Power Supply table - increased maximum VCC to 5.25V. Added 5V LVPECL DC Characteristics table. AC Characteristics table - increased VEE range to -5.25V to 2.375V, and VCC to 2.375V to 5.25V. Corrected Output Load AC Test Circuit Diagram, VEE range from" -1.8V to 0.375V" to "-3.25V to -0.375V". LVPECL clock Input Interface - added another CML driver diagram. Power Considerations - changed Power(core)max from 3.8V to 5.25V and recalculated equations. Absolute Maximum Ratings, corrected Supply Voltage & Negative Supply Voltage from 4.6V & -4.6V to 6V & -6V. www.icst.com/products/hiperclocks.html 18 Date 10/31/03 4/28/04 5/14/04 REV. B MAY 14, 2004