PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER GENERAL DESCRIPTION FEATURES The ICS843101I-312 is a low phase-noise frequency margining synthesizer with freHiPerClockS™ quency margining capability and is a member of the HiPerClockS™ family of high performance clock solutions from ICS. In the default mode, the device nominally generates a 312.5MHz LVPECL output clock signal from a 25MHz crystal input. There is also a frequency margining mode available where the device can be programmed, using the serial interface, to vary the output frequency up or down from nominal in 2% steps. The ICS843101I-312 is provided in a 16-pin TSSOP. • One 312.5MHz nominal LVPECL output ICS • Selectable crystal oscillator interface designed for 25MHz, 18pF parallel resonant crystal or LVCMOS/LVTTL single-ended input • Output frequency can be varied in 2% steps ± from nominal • VCO range: 560MHz - 690MHz • RMS phase jitter @ 312.5MHz, using a 25MHz crystal (1.875MHz - 20MHz): 0.52ps (typical) • Output supply modes Core/Output 3.3V/3.3V 3.3V/2.5V 2.5V/2.5V • -40°C to 85°C ambient operating temperature • Available in both standard and lead-free RoHS-complaint packages BLOCK DIAGRAM OE CLK Pullup Pulldown 1 ÷P 25MHz XTAL_IN PIN ASSIGNMENT OSC Phase Detector VCO ÷N 560 - 690MHz 0 XTAL_OUT SEL Pulldown S_CLOCK Pulldown S_DATA Pulldown S_LOAD Pulldown MODE Pulldown VEE S_LOAD S_DATA Q S_CLOCK SEL nQ OE VCCA V CC 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 MODE VCCO Q nQ VEE CLK XTAL_OUT XTAL_IN ICS843101I-312 ÷M 16-Lead TSSOP 4.4mm x 5.0mm x 0.92mm package body G Package Top View Serial Control The Preliminary Information presented herein represents a product in prototyping or pre-production. The noted characteristics are based on initial product characterization. Integrated Circuit Systems, Incorporated (ICS) reserves the right to change any circuitry or specifications without notice. 843101AGI-312 www.icst.com/products/hiperclocks.html 1 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER FUNCTIONAL DESCRIPTION The ICS843101I-312 features a fully integrated PLL and therefore requires no external components for setting the loop bandwidth. A 25MHz fundamental crystal is used as the input to the on chip oscillator. The output of the oscillator is fed into the pre-divider. In frequency margining mode, the 25MHz crystal frequency is divided by 2 and a 12.5MHz reference frequency is applied to the phase detector. The VCO of the PLL operates over a range of 560MHz to 690MHz. The output of the M divider is also applied to the phase detector. some values of M (either too high or too low), the PLL will not achieve lock. The output of the VCO is scaled by an output divider prior to being sent to the LVPECL output buffer. The divider provides a 50% output duty cycle. The relationship between the crystal input frequency, the M divider, the VCO frequency and the output frequency is provided in Table 1. When changing back from frequency margining mode to nominal mode, the device will return to the default nominal configuration that will provide 312.5 MHz output frequency. The default mode for the ICS843101I-312 is 312.5MHz output frequency using a 25MHz crystal. The output frequency can be changed by placing the device into the margining mode using the mode pin and using the serial interface to program the M feedback divider. Frequency margining mode operation occurs when the MODE input is HIGH. The phase detector and the M divider force the VCO output frequency to be M times the reference frequency by adjusting the VCO control voltage. Note that for Serial operation occurs when S_LOAD is HIGH. Serial data can be loaded in either the default mode or the frequency margining mode. The 6-bit shift register is loaded by sampling the S_DATA bits with the rising edge of S_CLOCK. After shifting in the 6-bit M divider value, S_LOAD is transitioned from HIGH to LOW which latches the contents of the shift-register into the M divider control register. When S_LOAD is LOW, any transitions of S_CLOCK or S_DATA are ignored. TABLE 1. FREQUENCY MARGIN FUNCTION TABLE XTAL (MHz) Pre-Divider (P) Reference Frequency (MHz) Feedback Divider (M) M-Data (Binary) VCO (MHz) Output Divider (N) 25 2 12.5 45 101101 562.5 2 Output Frequency (MHz) 281.25 % Change -10.0 25 2 12.5 46 101110 575 2 287.5 -8.0 25 2 12.5 47 101111 587.5 2 293.75 -6.0 25 2 12.5 48 110000 600 2 300 -4.0 25 2 12.5 49 110001 612.5 2 306.25 -2.0 25 2 12.5 50 110010 625 2 312.5 Nominal Mode 25 2 12.5 51 110011 637.5 2 318.75 2.0 25 2 12.5 52 110100 650 2 325 4.0 25 2 12.5 53 110101 662.5 2 331.25 6.0 25 2 12. 5 54 110110 675 2 337.5 8.0 25 2 12. 5 55 110111 687.5 2 343.75 10.0 SERIAL LOADING S_CLOCK M5 M4 S_DATA t S M3 M2 M1 M0 t t H S S_LOAD Time FIGURE 1. SERIAL LOAD OPERATIONS 843101AGI-312 www.icst.com/products/hiperclocks.html 2 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER TABLE 2. PIN DESCRIPTIONS Νυ μ β ε ρ Ναμ ε 1, 12 VEE Power 2 S_LOAD Input 3 S_DATA Input 4 S_CLOCK Input 5 SEL Input 6 OE Input 7 VCCA Power 8 Power 11 VCC XTAL_IN, XTAL_OUT CL K 13, 14 nQ, Q Ouput 15 VCCO Power 9, 10 Τψπ ε Input Input Δ ε σχριπ τιο ν Negative supply pins. Pulldown Controls the operation of the Serial input. LVCMOS/LVTTL interface levels. Shift register serial input. Data sampled on the rising edge of S_CLOCK. Pulldown LVCMOS/LVTTL interface levels. Clock in serial data present at S_DATA input into the shift register on the Pulldown rising edge of S_CLOCK. LVCMOS/LVTTL interface levels. Select pin. When HIGH, selects CLK input. Pulldown When LOW, selects XTAL inputs. LVCMOS/LVTTL interface levels. Output enable pin. Controls enabling and disabling of Q/nQ outputs. Pullup LVCMOS/LVTTL interface levels Analog supply pin. Core supply pin. Parallel resonant cr ystal interface. XTAL_OUT is the output, XTAL_IN is the input. Pulldown LVCMOS/LVTTL clock input. Differential output pair. LVPECL interface levels. Output supply pin. MODE pin. LOW = default mode. HIGH = frequency margining mode. 16 MODE Input Pulldown LVCMOS/LVTTL interface levels. NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values. TABLE 3. PIN CHARACTERISTICS Symbol Parameter CIN Input Capacitance 4 pF RPULLDOWN Input Pulldown Resistor 51 kΩ RPULLUP Input Pulldown Resistor 51 kΩ 843101AGI-312 Test Conditions Minimum www.icst.com/products/hiperclocks.html 3 Typical Maximum Units REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER TABLE 4A. OE CONTROL INPUT FUNCTION TABLE Input Outputs OE 0 Q , nQ HiZ 1 Enabled TABLE 4B. SEL CONTROL INPUT FUNCTION TABLE Input SEL 0 Selected Source XTAL_IN, XTAL_OUT 1 CLK TABLE 4C. MODE CONTROL INPUT FUNCTION TABLE Input Condition Mode 0 Q, nQ Default Mode 1 Frequency Margining Mode TABLE 4D. SERIAL MODE FUNCTION TABLE Inputs Conditions S_LOAD S_CLOCK S_DATA L X X H ↑ Data L X ↓ NOTE: L = LOW H = HIGH X = Don't care ↑ = Rising edge transition ↓ = Falling edge transition 843101AGI-312 Serial inputs are ignored. Serial input mode. Shift register is loaded with data on S_DATA on each rising edge of S_CLOCK. Contents of the shift register are latched. www.icst.com/products/hiperclocks.html 4 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC 4.6V Inputs, VI -0.5V to VCC + 0.5V Outputs, IO Continuous Current Surge Current 50mA 100mA Package Thermal Impedance, θJA 89°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 5A. POWER SUPPLY DC CHARACTERISTICS, VCC = VCCA = VCCO = 3.3V±5%, TA = -40°C TO 85°C Symbol Parameter VCC Core Supply Voltage Test Conditions Minimum Typical Maximum Units 3.135 3.3 3.465 V VCCA Analog Supply Voltage 3.135 3.3 3.465 V VCCO Output Supply Voltage 3.135 3.3 3.465 V IEE Power Supply Current 92 mA ICC Core Supply Current 78 mA ICCA Analog Supply Current 7 mA ICCO Output Supply Current 4 mA TABLE 5B. POWER SUPPLY DC CHARACTERISTICS, VCC = VCCA = 3.3V±5%,VCCO = 2.5V±5%, TA = -40°C TO 85°C Symbol Parameter VCC Core Supply Voltage Test Conditions Minimum Typical Maximum Units 3.135 3.3 3.465 V VCCA Analog Supply Voltage 3.135 3.3 3.465 V VCCO Output Supply Voltage 2.375 2.5 2.625 V IEE Power Supply Current 90 mA ICC Core Supply Current 78 mA ICCA Analog Supply Current 7 mA ICCO Output Supply Current 4 mA TABLE 5C. POWER SUPPLY DC CHARACTERISTICS, VCC = VCCA = VCCO = 2.5V±5%, TA = -40°C TO 85°C Symbol Parameter VCC VCCA Test Conditions Minimum Typical Maximum Units Core Supply Voltage 2.375 2.5 2.625 V Analog Supply Voltage 2.375 2.5 2.625 V VCCO Output Supply Voltage 2.375 2.5 2.625 V IEE Power Supply Current 84 mA ICC Core Supply Current 74 mA ICCA Analog Supply Current 7 mA ICCO Output Supply Current 3 mA 843101AGI-312 www.icst.com/products/hiperclocks.html 5 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER TABLE 5D. LVCMOS / LVTTL DC CHARACTERISTICS, TA = -40°C TO 85°C Symbol VIH VIL IIH IIL Δt/Δv Parameter Test Conditions Input High Voltage Input Low Voltage Input High Current Input Low Current Input Transistion Rise/Fall Rate Minimum Typical VCC = 3.3V Maximum Units 2 VCC + 0.3 V VCC = 2.5V 1. 7 VCC + 0.3 V VCC = 3.3V -0.3 0.8 V VCC = 2.5V -0.3 1.7 V CLK, SEL, S_DATA, S_LOAD, S_CLOCK, MODE VCC = VIN = 3.465 or 2.625V 150 µA OE VCC = VIN = 3.465 or 2.625V 5 µA CLK, SEL, S_DATA, S_LOAD, S_CLOCK, MODE VCC = 3.465V or 2.625V, VIN = 0V -5 µA OE VCC = 3.465V or 2.625V, VIN = 0V -150 µA OE, SEL, S_CLOCK, S_DATA, S_LOAD, MODE 20 ns/v Maximum Units TABLE 5E. LVPECL DC CHARACTERISTICS, TA = -40°C TO 85°C Symbol Parameter Test Conditions Minimum Typical VOH Output High Voltage; NOTE 1 VCCO - 1.4 VCCO - 0.9 V VOL Output Low Voltage; NOTE 1 VCCO - 2.0 VCCO - 1.7 V VSWING Peak-to-Peak Output Voltage Swing 0.6 1. 0 V NOTE 1: Outputs terminated with 50Ω to VCCO - 2V. TABLE 6. CRYSTAL CHARACTERISTICS Parameter Test Conditions Minimum Mode of Oscillation Typical Maximum Units Fundamental Frequency 25 MHz Equivalent Series Resistance (ESR) 50 Ω Shunt Capacitance 7 pF 100 µW Maximum Units Drive Level NOTE: Characterized using an 18pF parallel resonant cr ystal. TABLE 7. INPUT FREQUENCY CHARACTERISTICS, TA = -40°C Symbol Parameter fIN Input Frequency TO 85°C Test Conditions Typical 25 XTAL_IN/XTAL_OUT 25 S_CLOCK 843101AGI-312 Minimum CLK MHz MHz 50 www.icst.com/products/hiperclocks.html 6 MHz REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER TABLE 8A. AC CHARACTERISTICS, VCC = VCCA = VCCO = 3.3V±5%, TA = -40°C TO 85°C Symbol Parameter fOUT Output Frequency t jit(Ø) RMS Phase Jitter ; NOTE 1 tR / tF Output Rise/Fall Time Test Conditions Minimum Mode = LOW 312.5MHz, (1.875MHz - 20MHz) 20% to 80% odc Output Duty Cycle S_DATA to S_CLOCK tS Setup Time S_CLOCK to S_LOAD S_DATA to Hold Time tH S_CLOCK NOTE 1: Characterized using a 25MHz cr ystal. Typical Maximum Units 312.5 MHz 0.52 ps 425 ps 50 % 10 ns 10 ns 10 ns TABLE 8B. AC CHARACTERISTICS, VCC = VCCA = 3.3V±5%,VCCO = 2.5V±5%, TA = -40°C TO 85°C Symbol Parameter fOUT Output Frequency t jit(Ø) RMS Phase Jitter ; NOTE 1 t R / tF Output Rise/Fall Time Test Conditions Minimum Mode = LOW 312.5MHz, (1.875MHz - 20MHz) 20% to 80% odc Output Duty Cycle S_DATA to S_CLOCK tS Setup Time S_CLOCK to S_LOAD S_DATA to Hold Time tH S_CLOCK NOTE 1: Characterized using a 25MHz cr ystal. Typical Maximum Units 312.5 MHz 0.46 ps 405 ps 50 % 10 ns 10 ns 10 ns TABLE 8C. AC CHARACTERISTICS, VCC = VCCA = VCCO = 2.5V±5%, TA = -40°C TO 85°C Symbol Parameter fOUT Output Frequency t jit(Ø) RMS Phase Jitter ; NOTE 1 t R / tF Output Rise/Fall Time Test Conditions Minimum Mode = LOW 312.5MHz, (1.875MHz - 20MHz) 20% to 80% odc Output Duty Cycle S_DATA to S_CLOCK tS Setup Time S_CLOCK to S_LOAD S_DATA to Hold Time tH S_CLOCK NOTE 1: Characterized using a 25MHz cr ystal. 843101AGI-312 www.icst.com/products/hiperclocks.html 7 Typical Maximum Units 312.5 MHz 0.45 ps 375 ps 50 % 10 ns 10 ns 10 ns REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER TYPICAL PHASE NOISE AT 312.5MHZ (3.3V) ➤ 0 -10 -20 10 Gigabit Ethernet Filter -30 -40 312.5MHz -50 -60 RMS Phase Noise Jitter 1.875MHz to 20MHz = 0.52ps (typical) -80 Raw Phase Noise Data -90 -100 ➤ NOISE POWER dBc Hz -70 -110 -120 -130 -140 -150 -160 ➤ -170 -180 Phase Noise Result by adding 10 Gigabit Ethernet Filter to raw data -190 100 1k 10k 100k 1M 10M 100M OFFSET FREQUENCY (HZ) 843101AGI-312 www.icst.com/products/hiperclocks.html 8 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER PARAMETER MEASUREMENT INFORMATION 2.8V±0.04V 2V 2V Qx V CC , VCCA, VCCO SCOPE SCOPE Qx V CC , VCCA VCCO LVPECL LVPECL VEE nQx nQx VEE -0.5V ± 0.125V -1.3V ± 0.165V 3.3V CORE/3.3V OUTPUT LOAD AC TEST CIRCUIT 3.3V CORE/2.5V OUTPUT LOAD AC TEST CIRCUIT 2V Phase Noise Plot SCOPE Noise Power Qx V CC , VCCA, VCCO LVPECL Phase Noise Mask nQx VEE f1 Offset Frequency f2 RMS Jitter = Area Under the Masked Phase Noise Plot -0.5V ± 0.125V 2.5V CORE/2.5V OUTPUT LOAD AC TEST CIRCUIT RMS PHASE JITTER nQ 80% 80% Q VSW I N G Clock Outputs t PW 20% 20% tR t PERIOD tF odc = t PW x 100% t PERIOD OUTPUT RISE/FALL TIME 843101AGI-312 OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD www.icst.com/products/hiperclocks.html 9 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER APPLICATION INFORMATION POWER SUPPLY FILTERING TECHNIQUES As in any high speed analog circuitry, the power supply pins are vulnerable to random noise. The ICS843101I-312 provides separate power supplies to isolate any high switching noise from the outputs to the internal PLL. VCC, VCCA, and VCCO should be individually connected to the power supply plane through vias, and bypass capacitors should be used for each pin. To achieve optimum jitter performance, power supply isolation is required. Figure 2 illustrates how a 10Ω resistor along with a 10µF and a .01μF bypass capacitor should be connected to each VCCA. The 10Ω resistor can also be replaced by a ferrite bead. 3.3V or 2.5V VCC .01μF 10Ω VCCA .01μF 10μF FIGURE 2. POWER SUPPLY FILTERING CRYSTAL INPUT INTERFACE The ICS843101I-312 has been characterized with 18pF parallel resonant crystals. The capacitor values shown in Figure 3 below were determined using a 25MHz, 18pF par- allel resonant crystal and were chosen to minimize the ppm error. XTAL_OUT C1 27p X1 18pF Parallel Crystal XTAL_IN C2 27p Figure 3. CRYSTAL INPUt INTERFACE 843101AGI-312 www.icst.com/products/hiperclocks.html 10 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER RECOMMENDATIONS FOR UNUSED INPUT PINS INPUTS: CRYSTAL INPUT: For applications not requiring the use of the crystal oscillator input, both XTAL_IN and XTAL_OUT can be left floating. Though not required, but for additional protection, a 1kΩ resistor can be tied from XTAL_IN to ground. LVCMOS CONTROL PINS: All control pins have internal pull-ups or pull-downs; additional resistance is not required but can be added for additional protection. A 1kΩ resistor can be used. CLK INPUT: For applications not requiring the use of the test clock, it can be left floating. Though not required, but for additional protection, a 1kΩ resistor can be tied from the CLK input to ground. TERMINATION FOR 3.3V LVPECL OUTPUT 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 50Ω transmission lines. Matched impedance techniques should be used to maximize operating frequency and minimize signal distortion. Figures 4A and 4B 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. 3.3V Zo = 50Ω 125Ω FOUT FIN Zo = 50Ω Zo = 50Ω FOUT 50Ω 1 RTT = Z ((VOH + VOL) / (VCC – 2)) – 2 o FIN 50Ω Zo = 50Ω VCC - 2V RTT 84Ω FIGURE 4A. LVPECL OUTPUT TERMINATION 843101AGI-312 125Ω 84Ω FIGURE 4B. LVPECL OUTPUT TERMINATION www.icst.com/products/hiperclocks.html 11 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER TERMINATION FOR 2.5V LVPECL OUTPUT Figure 5A and Figure 5B 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 VCC=2.5V 2.5V 2.5V VCC=2.5V R1 250 Zo = 50 Ohm R3 250 + Zo = 50 Ohm + Zo = 50 Ohm - Zo = 50 Ohm 2,5V LVPECL Driv er - R1 50 2,5V LVPECL Driv er R2 62.5 R2 50 R4 62.5 R3 18 FIGURE 5B. 2.5V LVPECL DRIVER TERMINATION EXAMPLE FIGURE 5A. 2.5V LVPECL DRIVER TERMINATION EXAMPLE 2.5V VCC=2.5V Zo = 50 Ohm + Zo = 50 Ohm 2,5V LVPECL Driv er R1 50 R2 50 FIGURE 5C. 2.5V LVPECL TERMINATION EXAMPLE 843101AGI-312 www.icst.com/products/hiperclocks.html 12 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER POWER CONSIDERATIONS This section provides information on power dissipation and junction temperature for the ICS843101I-312. Equations and example calculations are also provided. 1. Power Dissipation. The total power dissipation for the ICS843101I-312 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 * 92mA = 318.78mW Power (outputs)MAX = 30mW/Loaded Output pair Total Power_MAX (3.465V, with all outputs switching) = 318.78mW + 30mW = 348.78mW 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 81.8°C/W per Table 9 below. Therefore, Tj for an ambient temperature of 85°C with all outputs switching is: 85°C + 0.349W *81.8°C/W = 113.5°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 9. THERMAL RESISTANCE θJA FOR 16-PIN TSSOP, FORCED CONVECTION θJA by Velocity (Linear Feet per Minute) 0 Single-Layer PCB, JEDEC Standard Test Boards Multi-Layer PCB, JEDEC Standard Test Boards 137.1°C/W 89.0°C/W 200 118.2°C/W 81.8°C/W 500 106.8°C/W 78.1°C/W NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs. 843101AGI-312 www.icst.com/products/hiperclocks.html 13 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER 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 6. VCCO Q1 VOUT RL 50 VCCO - 2V FIGURE 6. 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 CCO_MAX • -V OH_MAX OL_MAX CCO_MAX -V OL_MAX CCO_MAX – 0.9V ) = 0.9V For logic low, VOUT = V (V =V =V CCO_MAX – 1.7V ) = 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 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 - 0.9V)/50Ω] * 0.9V = 19.8mW 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 - 1.7V)/50Ω] * 1.7V = 10.2mW Total Power Dissipation per output pair = Pd_H + Pd_L = 30mW 843101AGI-312 www.icst.com/products/hiperclocks.html 14 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER RELIABILITY INFORMATION TABLE 10. θJAVS. AIR FLOW TABLE FOR 16 LEAD TSSOP θJA by Velocity (Linear Feet per Minute) 0 Single-Layer PCB, JEDEC Standard Test Boards Multi-Layer PCB, JEDEC Standard Test Boards 137.1°C/W 89.0°C/W 200 118.2°C/W 81.8°C/W 500 106.8°C/W 78.1°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 ICS843101I-312 is: 4093 843101AGI-312 www.icst.com/products/hiperclocks.html 15 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER PACKAGE OUTLINE - G SUFFIX FOR 16 LEAD TSSOP TABLE 11. PACKAGE DIMENSIONS Millimeters SYMBOL Minimum N Maximum 16 A -- 1.20 A1 0.05 0.15 A2 0.80 1.05 b 0.19 0.30 c 0.09 0.20 D 4.90 5.10 E 6.40 BASIC E1 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 843101AGI-312 www.icst.com/products/hiperclocks.html 16 REV. A NOVEMBER 1, 2005 PRELIMINARY Integrated Circuit Systems, Inc. ICS843101I-312 FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER TABLE 12. ORDERING INFORMATION Part/Order Number Marking Package Shipping Packaging Temperature ICS843101AGI-312 TBD 16 Lead TSSOP tube -40°C to 85°C ICS843101AGI-312T TBD 16 Lead TSSOP 2500 tape & reel -40°C to 85°C ICS843101AGI-312LF TBD 16 Lead "Lead-Free" TSSOP tube -40°C to 85°C ICS843101AGI-312LFT TBD 16 Lead "Lead-Free" TSSOP 2500 tape & reel -40°C to 85°C NOTE: Par ts that are ordered with an "LF" suffix to the par t number are the Pb-Free configuration and are RoHS complaint. The aforementioned trademarks, HiPerClockS and FemtoClocks are trademarks 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. 843101AGI-312 www.icst.com/products/hiperclocks.html 17 REV. A NOVEMBER 1, 2005