ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR General Description Features The ICS840271I is a PLL-based Frequency Translator intended for use in telecommunication HiPerClockS™ applications such as Synchronous Ethernet. The internal PLL translates Ethernet clock frequencies such as 125MHz (1Gb Ethernet), 156.25MHz (10GbE XAUI) and 161.1328MHz (10Gb Ethernet) to an output frequency of 25MHz. The PLL does not any require external components. The input frequency is selectable by a 2-pin interface. The ICS840271I is optimized for low cycle-to-cycle jitter on the 25MHz output signal. The input of the device accepts differential (LVPECL, LVDS, LVHSTL, SSTL, HCSL) or single-ended (LVCMOS) signals. The extended temperature range supports telecommunication and networking equipment requirements. The ICS840271I uses a small RoHS 6, 8-pin TSSOP package and is an effective solution for space-constrained applications. • Clock frequency translator for Synchronous Ethernet applications • One single-ended output (LVCMOS or LVTTL levels), 16Ω output impedance • Differential input pair (CLK, nCLK) accepts LVPECL, LVDS, LVHSTL, SSTL, HCSL input levels • Supports input clock frequencies of: 125MHz, 156.25MHz or 161.1328MHz • • Generates a 25MHz output clock signal • Internal PLL is optimized for low cycle-to-cycle jitter at the output • • • Full 3.3V or 2.5V supply voltage ICS Internal resistor bias on nCLK pin allows the user to drive CLK input with external single-ended (LVCMOS/LVTTL) input levels -40°C to 85°C ambient operating temperature Available in lead-free (RoHS 6) package Pin Assignment Block Diagram VDDA CLK nCLK SEL(1:0) Predivider SEL0 PLL Feedback divider Output divider Q 25 MHz Input Control Logic 00 = PLL Bypass 01 = 161.1328125 MHz 10 = 156.2500000 MHz 11 = 125.0000000 MHz IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 1 CLK nCLK 1 2 3 4 8 7 6 5 VDD Q GND SEL1 ICS840271I 8 Lead TSSOP 4.40mm x 3.0mm x 0.925mm package body G Package Top View ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Table 1. Pin Descriptions Number Name Type Description 1 VDDA Power 2 SEL0 Input Pulldown Selects the input reference frequency and the PLL bypass mode. LVCMOS/LVTTL interface levels. See Table 3. 3 CLK Input Pulldown Non-inverting differential clock input. 4 nCLK Input Pullup/ Pulldown Inverting differential clock input. Internal resistor bias to VDD/2. 5 SEL1 Input Pullup 6 GND Power Power supply ground. 7 Q Output Single-ended clock output. LVCMOS/LVTTL interface levels. 8 VDD Power Core supply pin. Analog supply pin. Selects the input reference frequency and the PLL bypass mode. LVCMOS/LVTTL interface levels. See Table 3. 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 CIN Input Capacitance 4 pF RPULLUP Input Pullup Resistor 51 kΩ 51 kΩ VDD = 3.465V 16 Ω VDD = 2.625V 19 Ω RPULLDOWN Input Pulldown Resistor ROUT Output Impedance Typical Maximum Units Function Tables Table 3. SEL[1:0] Function Table Inputs SEL1 SEL0 CLK, nCLK (MHz) Mode Output (MHz) 0 0 REF PLL Bypass REF/ 5 0 1 161.1328125 PLL Enabled 25 1 (default) 0 (default) 156.25 PLL Enabled 25 1 1 125 PLL Enabled 25 NOTE: REF = Input clock signal frequency IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 2 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Absolute Maximum Ratings 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. Item Rating Supply Voltage, VDD 4.6V Inputs, VI -0.5V to VDD + 0.5V Outputs, IO (LVCMOS) -0.5V to VDD + 0.5V Package Thermal Impedance, θJA 129.5°C/W (0 mps) Storage Temperature, TSTG -65°C to 150°C DC Electrical Characteristics Table 4A. Power Supply DC Characteristics, VDD = 3.3V±5%, TA = -40°C to 85°C Symbol Parameter VDD Core Supply Voltage VDDA Analog Supply Voltage IDD IDDA Test Conditions Minimum Typical Maximum Units 3.135 3.3 3.465 V VDD – 0.08 3.3 VDD V Power Supply Current 75 mA Analog Supply Current 8 mA Table 4B. Power Supply DC Characteristics, VDD = 2.5V±5%, TA = -40°C to 85°C Symbol Parameter VDD Core Supply Voltage VDDA Analog Supply Voltage IDD IDDA Test Conditions Minimum Typical Maximum Units 2.375 2.5 2.625 V VDD – 0.08 2.5 VDD V Power Supply Current 72 mA Analog Supply Current 8 mA IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 3 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Table 4C. LVCMOS/LVTTL DC Characteristics, VDD = 3.3V±5% or 2.5V±5%, TA = -40°C to 85°C Symbol Parameter VIH Input High Voltage VIL Input Low Voltage IIH Input High Current IIL Input Low Current VOH Output High Voltage VOL Output Low Voltage Test Conditions Minimum VDD = 3.3V Typical Maximum Units 2 VDD + 0.3 V VDD = 2.5V 1.7 VDD + 0.3 V VDD = 3.3V -0.3 0.8 V VDD = 2.5V -0.3 0.7 V SEL1 VDD = VIN = 3.465V or 2.625V 5 µA SEL0 VDD = VIN = 3.465V or 2.625V 150 µA SEL1 VDD = 3.465V, VIN = 0V -150 µA SEL0 VDD = 3.465V, VIN = 0V -5 µA VDD = 3.465V, IOH = 12mA 2.6 V VDD = 2.625V, IOH = 12mA 1.8 V VDD = 3.465V or 2.625V, IOL = -12mA 0.5 V Maximum Units 150 µA Table 4D. Differential DC Characteristics, VDD = 3.3V±5% or 2.5V±5%, TA = -40°C to 85°C Symbol Parameter IIH Input High Current IIL Test Conditions CLK/nCLK Minimum VDD = VIN = 3.465V or 2.625V Typical CLK VDD = 3.465V or 2.625V, VIN = 0V -5 µA nCLK VDD = 3.465V or 2.625V, VIN = 0V -150 µA Input Low Current VPP Peak-to-Peak Voltage; NOTE 1 VCMR Common Mode Input Voltage; NOTE 1, 2 0.15 1.3 V GND + 0.5 VDD – 0.85 V NOTE 1: VIL should not be less than -0.3V. NOTE 2: Common mode input voltage is defined as VIH. IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 4 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR AC Electrical Characteristics Table 5A. AC Characteristics, VDD = 3.3V±5%, TA = -40°C to 85°C Symbol Parameter fOUT Output Frequency tjit(cc)) Cycle-to-Cycle Jitter tLOCK PLL Lock Time tR / tF Output Rise/Fall Time odc Output Duty Cycle Test Conditions Minimum Typical Maximum 25 Units MHz SEL0 ≠ SEL1 40 ps SEL0 = SEL1 = 1 15 ps SEL1 = 0, SEL0 = 1 1 s SEL 1 = 1, SEL0 = X 50 ms 200 700 ps 47 53 % 20% to 80% NOTE: Electrical parameters are guaranteed over the specified ambient operating temperature range, which is established when the device is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after thermal equilibrium has been reached under these conditions. Table 5B. AC Characteristics, VDD = 2.5V±5%, TA = -40°C to 85°C Symbol Parameter fOUT Output Frequency tjit(cc)) Cycle-to-Cycle Jitter tLOCK PLL Lock Time tR / tF Output Rise/Fall Time odc Output Duty Cycle Test Conditions Minimum Typical Maximum 25 Units MHz SEL0 ≠ SEL1 50 ps SEL0 = SEL1 = 1 15 ps SEL1 = 0, SEL0 = 1 1 s SEL 1 = 1, SEL0 = X 50 ms 200 700 ps 47 53 % 20% to 80% NOTE: Electrical parameters are guaranteed over the specified ambient operating temperature range, which is established when the device is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after thermal equilibrium has been reached under these conditions. IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 5 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Parameter Measurement Information 1.25V±5% 1.65V±5% 1.25V±5% 1.65V±5% SCOPE VDD VDDA VDDA Qx LVCMOS SCOPE VDD Qx LVCMOS GND GND -1.65V±5% -1.25V±5% 3.3V Output Load AC Test Circuit 2.5V Output Load AC Test Circuit VDD Q nCLK ➤ Cross Points PP V CMR tcycle n ➤ V ➤ tcycle n+1 ➤ tjit(cc) = |tcycle n – tcycle n+1| 1000 Cycles CLK GND Differential Input Level Cycle-to-Cycle Jitter V DDO 2 Q t PW t PERIOD t PW 80% tR tF 20% 20% Q odc = 80% x 100% t PERIOD Output Duty Cycle/Pulse Width/Period IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Output Rise/Fall Time 6 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Application Information Power Supply Filtering Technique As in any high speed analog circuitry, the power supply pins are vulnerable to random noise. To achieve optimum jitter performance, power supply isolation is required. The ICS840271I provides separate power supplies to isolate any high switching noise from the outputs to the internal PLL. VDD and VDDA should be individually connected to the power supply plane through vias, and 0.01µF bypass capacitors should be used for each pin. Figure 1 illustrates this for a generic VDD pin and also shows that VDDA requires that an additional 10Ω resistor along with a 10µF bypass capacitor be connected to the VDDA pin. 3.3V or 2.5V VDD .01µF 10Ω .01µF 10µF VDDA Figure 1. Power Supply Filtering Wiring the Differential Input to Accept Single Ended Levels Figure 2 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 2. Single-Ended Signal Driving Differential Input Recommendations for Unused Input Pins Inputs: LVCMOS Control Pins All control pins have internal pullups or pulldowns; additional resistance is not required but can be added for additional protection. A 1kΩ resistor can be used. IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 7 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Differential Clock Input Interface The CLK /nCLK accepts LVDS, LVPECL, LVHSTL, SSTL, HCSL and other differential signals. Both signals must meet the VPP and VCMR input requirements. Figures 3A to 3F show interface examples for the HiPerClockS CLK/nCLK input driven by the most common driver types. The input interfaces suggested here are examples only. Please consult with the vendor of the driver component to confirm the driver termination requirements. For example, in Figure 3A, the input termination applies for IDT HiPerClockS open emitter LVHSTL drivers. If you are using an LVHSTL driver from another vendor, use their termination recommendation. 3.3V 3.3V 3.3V 1.8V Zo = 50Ω Zo = 50Ω CLK CLK Zo = 50Ω nCLK Zo = 50Ω nCLK HiPerClockS Input LVHSTL R1 50 IDT HiPerClockS LVHSTL Driver HiPerClockS Input LVPECL R2 50 R1 50 R2 50 R2 50 Figure 3A. HiPerClockS CLK/nCLK Input Driven by an IDT Open Emitter HiPerClockS LVHSTL Driver Figure 3B. HiPerClockS CLK/nCLK Input Driven by a 3.3V LVPECL Driver 3.3V 3.3V 3.3V R3 125 3.3V R4 125 3.3V Zo = 50Ω Zo = 50Ω CLK CLK R1 100 Zo = 50Ω nCLK HiPerClockS Input LVPECL R1 84 R2 84 Figure 3C. HiPerClockS CLK/nCLK Input Driven by a 3.3V LVPECL Driver 2.5V nCLK Zo = 50Ω Receiver LVDS Figure 3D. HiPerClockS CLK/nCLK Input Driven by a 3.3V LVDS Driver 2.5V 3.3V 3.3V 2.5V *R3 33 R3 120 Zo = 50Ω R4 120 Zo = 60Ω CLK CLK Zo = 50Ω Zo = 60Ω nCLK nCLK HCSL *R4 33 R1 50 R2 50 HiPerClockS Input HiPerClockS SSTL R1 120 R2 120 *Optional – R3 and R4 can be 0Ω Figure 3F. HiPerClockS CLK/nCLK Input Driven by a 2.5V SSTL Driver Figure 3E. HiPerClockS CLK/nCLK Input Driven by a 3.3V HCSL Driver IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 8 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Schematic Example Figure 4 shows an example of ICS840271I applications schematic. In this example, the device is operated at VDD = 3.3V. The input is driven by either a 3.3V LVPECL or LVDS driver. One example of LVCMOS termination is shown in this schematic. The decoupling capacitors should be located a close as possible to the power pin. Logic Input Pin Examples Set Logic Input to '1' VDD Set Logic Input to '0' VDD RU1 1K RU2 Not Install To Logic Input pins RD1 Not Install VDD R1 To Logic Input pins RD2 1K VDD C1 0.01u VDDA 10 C2 0.1u U1 C3 10u SEL0 1 2 3 4 VDDA SEL0 CLK nCLK VDD Q GND SEL1 VDD R3 125 8 7 6 5 Q R2 33 Zo = 50 Ohm SEL1 LVCMOS R4 125 CLK Zo = 50 nCLK Zo = 50 LVPECL Driv er R5 84 R6 84 Figure 4. ICS840271I Schematic layout IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 9 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Power Considerations This section provides information on power dissipation and junction temperature for the ICS840271I. Equations and example calculations are also provided. 1. Power Dissipation. The total power dissipation for the ICS840271I is the sum of the core power plus the analog 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. • Power (core)MAX = VDD_MAX * (IDD + IDDA) = 3.465V *(75mA + 8mA) = 287.6mW • Output Impedance ROUT Power Dissipation due to Loading 50Ω to VDD/2 Output Current IOUT = VDD_MAX / [2 * (50Ω + ROUT)] = 3.465V / [2 * (50Ω + 16Ω)] = 26.25mA • Power Dissipation on the ROUT per LVCMOS output Power (ROUT) = ROUT * (IOUT)2 = 16Ω * (26.25mA)2 = 11mW per output Total Power Dissipation • Total Power = Power (core)MAX + Total Power (ROUT) = 287.6mW + 11mW = 298.6mW 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 HiPerClockS 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 no air flow and a multi-layer board, the appropriate value is 129.5°C/W per Table 6 below. Therefore, Tj for an ambient temperature of 85°C with all outputs switching is: 85°C + 0.299W *129.5°C/W = 123.7°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 (multi-layer). Table 6. Thermal Resistance θJA for 8 Lead TSSOP, Forced Convection θJA by Velocity Meters per Second Multi-Layer PCB, JEDEC Standard Test Boards IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 0 1 2.5 129.5°C/W 125.5°C/W 123.5°C/W 10 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Reliability Information Table 7. θJA vs. Air Flow Table for a 8 Lead TSSOP θJA vs. Air Flow Meters per Second Multi-Layer PCB, JEDEC Standard Test Boards 0 1 2.5 129.5°C/W 125.5°C/W 123.5°C/W Transistor Count The transistor count for ICS840271I is: 2732 Package Outline and Package Dimensions Package Outline - G Suffix for 8 Lead TSSOP Table 8. Package Dimensions All Dimensions in Millimeters Symbol Minimum Maximum N 8 A 1.20 A1 0.5 0.15 A2 0.80 1.05 b 0.19 0.30 c 0.09 0.20 D 2.90 3.10 E 6.40 Basic E1 4.30 4.50 e 0.65 Basic L 0.45 0.75 α 0° 8° aaa 0.10 Reference Document: JEDEC Publication 95, MO-153 IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 11 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Ordering Information Table 9. Ordering Information Part/Order Number 840271BGILF 840271BGILFT Marking 71BIL 71BIL Package “Lead-Free” 8 Lead TSSOP “Lead-Free” 8 Lead TSSOP Shipping Packaging Tube 2500 Tape & Reel Temperature -40°C to 85°C -40°C to 85°C NOTE: Parts that are ordered with an "LF" suffix to the part number are the Pb-Free configuration and are RoHS compliant. While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes no responsibility for either its use or for the 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 IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT does not authorize or warrant any IDT product for use in life support devices or critical medical instruments. IDT™ / ICS™ SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR 12 ICS840271BGI REV. A APRIL 23, 2009 ICS840271I SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Contact Information: www.IDT.com www.IDT.com Sales Technical Support 800-345-7015 (inside USA) +408-284-8200 (outside USA) Fax: 408-284-2775 www.IDT.com/go/contactIDT [email protected] +480-763-2056 Corporate Headquarters Integrated Device Technology, Inc. 6024 Silver Creek Valley Road San Jose, CA 95138 United States 800-345-7015 (inside USA) +408-284-8200 (outside USA) © 2009 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are trademarks of Integrated Device Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or registered trademarks used to identify products or services of their respective owners. Printed in USA