Synchronous Ethernet Frequency Translator ICS840272I DATA SHEET General Description Features The ICS840272I is a PLL-based Frequency Translator intended for use in Synchronous Ethernet applications. This high performance device is optimized to generate 25MHz and 8kHz LVCMOS clock outputs. The ICS840272I accepts the following differential or single-ended input signals: 161.1328125MHz (10GbE Mode), 156.25MHz (1GbE Mode), or 125MHz (Recovered clock from 10/100/1000BaseT Ethernet PHY). The extended temperature range supports telecommunication and networking end equipment requirements. • Two single-ended outputs (LVCMOS or LVTTL levels), output impedance: 17Ω • • • Single-ended lock detect output (LVCMOS or LVTTL levels) • Internal resistor bias on nCLK pin allows the user to drive CLK input with external single-ended (LVCMOS/ LVTTL) input levels • Selectable input frequencies: 161.1328MHz, 156.25MHz or 125MHz • • • • Output frequency: 25MHz, 8kHz Pin Assignment VDD LOCK_DT REF_SEL SEL0 SEL1 OE VDDA GND 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 VDDO QA QB GND CLK0 nCLK0 CLK1 nCLK1 Two selectable differential clock inputs Differential input pair (CLKx, nCLKx) accepts LVPECL, LVDS, LVHSTL, SSTL, HCSL input levels Full 3.3V supply voltage -40°C to 85°C ambient operating temperature Available in lead-free (RoHS 6) package ICS840272I 16 Lead TSSOP 4.40mm x 5.0mm x 0.925mm package body G Package Top View Block Diagram LOCK_DT CLK0 0 Pulldown nCLK0 Pullup/Pulldown 0 P CLK1 Pulldown Pullup/Pulldown QA 25MHz N PLL 1 1 nCLK1 ÷3125 REF_SEL Pulldown QB 8kHz M Input Control SEL[1:0] Pulldown:Pullup 00 = PLL Bypass, 25MHz Input 01 = 161.1328125MHz (default) 10 = 156.25MHz 11 = 125MHz OE Pulldown ICS840272AGI REVISION A JULY 26, 2010 1 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Table 1. Pin Descriptions Number Name 1 VDD Power Type Description Core supply pin. 2 LOCK_DT Output Lock detect. Logic HIGH when PLL is locked. 3 REF_SEL Input Pulldown 4 SEL0 Input Pullup Selects the input reference frequency and the PLL bypass mode. See Table 3A. LVCMOS/LVTTL interface levels. 5 SEL1 Input Pulldown Selects the input reference frequency and the PLL bypass mode. See Table 3A. LVCMOS/LVTTL interface levels. 6 OE Input Pulldown 8kHz output enable pin. When LOW, QB is disabled. When HIGH, QB is enabled. LVCMOS/LVTTL interface levels. See Table 3B. 7 VDDA Power Analog supply pin. 8, 13 GND Power Power supply ground. 9 nCLK1 Input Pullup/ Pulldown Inverting differential clock input. Internal resistor bias to VDD/2. 10 CLK1 Input Pulldown Non-inverting differential clock input. 11 nCLK0 Input Pullup/ Pulldown Inverting differential clock input. Internal resistor bias to VDD/2. 12 CLK0 Input Pulldown Non-inverting differential clock input. 14 QB Output Single-ended clock output. LVCMOS/LVTTL interface levels. 15 QA Output Single-ended clock output. LVCMOS/LVTTL interface levels. 16 VDDO Power Output supply pin. Selects the input reference clock. When LOW, selects CLK0, nCLK0. When HIGH, selects CLK1, nCLK1. LVCMOS/LVTTL 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 CIN Input Capacitance 4 pF RPULLUP Input Pullup Resistor 51 kΩ RPULLDOWN Input Pulldown Resistor 51 kΩ ROUT Output Impedance 17 Ω ICS840272AGI REVISION A JULY 26, 2010 Test Conditions VDDO = 3.465V 2 Minimum Typical Maximum Units ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Function Tables Table 3A. SEL[1:0] Function Table Inputs Function Output (MHz) SEL1 SEL0 CLKx, nCLKx (MHz) Mode QA 0 0 25 PLL Bypass 25 0 (default) 1 (default) 161.1328125 PLL Enabled 25 1 0 156.25 PLL Enabled 25 1 1 125 PLL Enabled 25 Table 3B. OE Function Table Control Input Function OE QB Output 0 (default) Disabled (High impedance) 1 Enabled ICS840272AGI REVISION A JULY 26, 2010 3 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet 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 VDDO + 0.5V Package Thermal Impedance, θJA 81.2°C/W (0 mps) Storage Temperature, TSTG -65°C to 150°C DC Electrical Characteristics Table 4A. Power Supply DC Characteristics, VDD = VDDO = 3.3V±5%, TA = -40°C to 85°C Symbol Parameter VDD Core Supply Voltage VDDA Test Conditions Minimum Typical Maximum Units 3.135 3.3 3.465 V Analog Supply Voltage VDD – 0.11 3.3 VDD V VDDO Output Supply Voltage 3.135 3.3 3.465 V IDD Power Supply Current 57 mA IDDA Analog Supply Current 11 mA IDDO Output Supply Current 5 mA Table 4B. LVCMOS/LVTTL DC Characteristics, VDD = VDDO = 3.3V±5%, TA = -40°C to 85°C Symbol Parameter VIH VIL IIH IIL Test Conditions Minimum Input High Voltage VDD = 3.465V Input Low Voltage VDD = 3.465V Input High Current Input Low Current Typical Maximum Units 2 VDD + 0.3 V -0.3 0.8 V OE, SEL1, REF_SEL VDD = VIN = 3.465V 150 µA SEL0 VDD = VIN = 3.465V 5 µA OE, SEL1, REF_SEL VDD = 3.465V, VIN = 0V -5 µA SEL0 VDD = 3.465V, VIN = 0V -150 µA 2.6 V VOH Output High Voltage IOH = -12mA VOL Output Low Voltage IOL = 12mA ICS840272AGI REVISION A JULY 26, 2010 4 0.5 V ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Table 4C. Differential DC Characteristics, VDD = VDDO = 3.3V±5%, TA = -40°C to 85°C Symbol Parameter Test Conditions IIH Input High Current IIL Input Low Current VPP Peak-to-Peak Voltage; NOTE 1 VCMR Common Mode Input Voltage; NOTE 1, 2 Minimum Typical Maximum Units 150 µA CLK[0:1], nCLK[0:1] VDD = VIN = 3.465V CLK[0:1] VDD = 3.465V, VIN = 0V -5 µA nCLK[0:1] VDD = 3.465V, VIN = 0V -150 µA 0.15 1.3 V GND + 0.5 VDD – 0.85 V Maximum Units NOTE 1: VIL should not be less than -0.3V. NOTE 2: Common mode input voltage is defined as VIH. AC Electrical Characteristics Table 5. AC Characteristics, VDD = VDDO = 3.3V±5%, TA = -40°C to 85°C Symbol Parameter fOUT Output Frequency tjit(Ø) RMS Phase Jitter (Random); NOTE 1 QA 25MHz, Integration Range: 12kHz – 10MHz tjit(cc) Cycle-to-Cycle Jitter QA 25MHz tR / t F Output Rise/Fall Time QA 20% to 80% QB 20% to 80% odc Output Duty Cycle Test Conditions Minimum Typical QA 25 MHz QB 8 kHz 1.1 ps 37 ps 450 1100 ps 450 1100 ps QA 47 53 % QB 47 53 % 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. NOTE 1: Refer to Phase Noise plot. ICS840272AGI REVISION A JULY 26, 2010 5 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Typical Phase Noise at 25MHz Noise Power dBc Hz Additive Phase Jitter @ 25MHz 12kHz to 10MHz = 1.1ps (typical) Offset Frequency (Hz) ICS840272AGI REVISION A JULY 26, 2010 6 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Parameter Measurement Information 1.65V±5% 1.65V±5% VDD SCOPE VDD, VDDO nCLK[0:1] VDDA Qx LVCMOS V V Cross Points PP CMR CLK[0:1] GND GND -1.65V±5% LVCMOS Output Load AC Test Circuit Differential Input Level V DDO 2 QA, QB 80% 80% tR tF t PW t PERIOD QA, QB odc = t PW 20% 20% x 100% t PERIOD Output Duty Cycle/Pulse Width/Period Output Rise/Fall Time Noise Power Phase Noise Plot V V V DDORx DDORx 2 DDORx 2 tcycle n ➤ QA, QB ➤ 2 tcycle n+1 ➤ ➤ tjit(cc) = |tcycle n – tcycle n+1| 1000 Cycles f1 Offset Frequency f2 RMS Jitter = Area Under Curve Defined by the Offset Frequency Markers RMS Phase Jitter ICS840272AGI REVISION A JULY 26, 2010 Cycle-to-Cycle Jitter 7 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Applications 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 ICS840272I provides separate power supplies to isolate any high switching noise from the outputs to the internal PLL. VDD, VDDA and VDDO 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 VDD .01µF 10Ω .01µF 10µF VDDA Figure 1. Power Supply Filtering Recommendations for Unused Input and Output Pins Inputs: Outputs: LVCMOS Control Pins LVCMOS Outputs 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. All unused LVCMOS output can be left floating. There should be no trace attached. CLK/nCLK Inputs For applications not requiring the use of the differential input, both CLK and nCLK can be left floating. Though not required, but for additional protection, a 1kΩ resistor can be tied from CLK to ground. ICS840272AGI REVISION A JULY 26, 2010 8 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Wiring the Differential Input to Accept Single-Ended Levels Figure 2 shows how a differential input can be wired to accept single ended levels. The reference voltage VREF = VDD/2 is generated by the bias resistors R1 and R2. The bypass capacitor (C1) is used to help filter noise on the DC bias. This bias circuit should be located as close to the input pin as possible. The ratio of R1 and R2 might need to be adjusted to position the VREF in the center of the input voltage swing. For example, if the input clock swing is 2.5V and VDD = 3.3V, R1 and R2 value should be adjusted to set VREF at 1.25V. The values below are for when both the single ended swing and VDD are at the same voltage. This configuration requires that the sum of the output impedance of the driver (Ro) and the series resistance (Rs) equals the transmission line impedance. In addition, matched termination at the input will attenuate the signal in half. This can be done in one of two ways. First, R3 and R4 in parallel should equal the transmission line impedance. For most 50Ω applications, R3 and R4 can be 100Ω. The values of the resistors can be increased to reduce the loading for slower and weaker LVCMOS driver. When using single-ended signaling, the noise rejection benefits of differential signaling are reduced. Even though the differential input can handle full rail LVCMOS signaling, it is recommended that the amplitude be reduced. The datasheet specifies a lower differential amplitude, however this only applies to differential signals. For single-ended applications, the swing can be larger, however VIL cannot be less than -0.3V and VIH cannot be more than VDD + 0.3V. Though some of the recommended components might not be used, the pads should be placed in the layout. They can be utilized for debugging purposes. The datasheet specifications are characterized and guaranteed by using a differential signal. Figure 2. Recommended Schematic for Wiring a Differential Input to Accept Single-ended Levels ICS840272AGI REVISION A JULY 26, 2010 9 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet 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 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 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 CLK Zo = 50Ω CLK Zo = 50Ω nCLK Zo = 50Ω R1 50Ω IDT LVHSTL Driver R1 50Ω Differential Input LVHSTL R2 50Ω Differential Input LVPECL nCLK R2 50Ω R2 50Ω Figure 3A. CLK/nCLK Input Driven by an IDT Open Emitter LVHSTL Driver Figure 3B. CLK/nCLK Input Driven by a 3.3V LVPECL Driver 3.3V 3.3V 3.3V R3 125Ω 3.3V R4 125Ω 3.3V Zo = 50Ω Zo = 50Ω CLK CLK R1 100 Zo = 50Ω nCLK Differential Input LVPECL R1 84Ω R2 84Ω nCLK Zo = 50Ω Receiver LVDS Figure 3C. CLK/nCLK Input Driven by a 3.3V LVPECL Driver Figure 3D. CLK/nCLK Input Driven by a 3.3V LVDS Driver 2.5V 3.3V 3.3V 3.3V 2.5V *R3 33Ω R3 120Ω Zo = 50Ω R4 120Ω Zo = 60Ω CLK CLK Zo = 50Ω Zo = 60Ω nCLK nCLK HCSL *R4 33Ω R1 50Ω R2 50Ω Differential Input SSTL R1 120Ω R2 120Ω Differential Input *Optional – R3 and R4 can be 0Ω Figure 3F. CLK/nCLK Input Driven by a 2.5V SSTL Driver Figure 3E. CLK/nCLK Input Driven by a 3.3V HCSL Driver ICS840272AGI REVISION A JULY 26, 2010 10 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Schematic Example Figure 4 shows an example of ICS840272I 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. Two examples of LVCMOS terminations are shown in this schematic. The decoupling capacitors should be located as close as possible to the power pin. Logic Control Input Examples Set Logic Input to '1' VDD Set Logic Input to '0' VDD RU1 1K R8 35 RU2 Not Install To Logic Input pins RD1 Not Install RD2 1K To Logic Input pins U1 C3 0.1u VDD VDDA R1 10 C1 10uF Zo = 50 Ohm VDD C2 0.01u 1 2 3 4 5 6 7 8 LVCMOS VDD VDDO LOCK_DT QA REF_SEL QB SEL0 GND SEL1 CLK0 OE nCLK0 VDDA CLK1 GND nCLK1 16 15 14 13 12 11 10 9 VDD C4 0.1u LD1 LED R9 100 Zo = 50 Ohm R10 100 R2 2.7K LVCMOS VDD LVDS Optional Termination Zo = 50 Ohm R3 100 Zo = 50 Ohm Unused output can be left floating. There should no trace attached to unused output. Device characterized with all outputs terminated. VDD VDD Zo = 50 Ohm R4 125 R6 125 Zo = 50 Ohm LVPECL R5 84 R7 84 Figure 4. ICS840272I Schematic Example ICS840272AGI REVISION A JULY 26, 2010 11 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Power Considerations This section provides information on power dissipation and junction temperature for the ICS840272I. Equations and example calculations are also provided. 1. Power Dissipation. The total power dissipation for the ICS840272I 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+ IDDO) = 3.465V *(57mA + 11mA + 5mA) = 252.9mW • Output Impedance ROUT Power Dissipation due to Loading 50Ω to VDD/2 Output Current IOUT = VDD_MAX / [2 * (50Ω + ROUT)] = 3.465V / [2 * (50Ω + 17Ω)] = 25.86mA • Total Power Dissipation on the ROUT per LVCMOS output Power (ROUT) = ROUT * (IOUT)2 = 17Ω * (25.86mA)2 = 11.4mW per output Total Power (ROUT) = 11.4mW * 2 = 22.8mW Total Power Dissipation • Total Power = Power (core)MAX + Total Power (ROUT) = 252.9mW + 22.8mW = 275.7mW 2. Junction Temperature. Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad directly affects the reliability of the device. The maximum recommended junction temperature is 125°C. Limiting the internal transistor junction temperature, Tj, to 125°C ensures that the bond wire and bond pad temperature remains below 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 81.2°C/W per Table 6 below. Therefore, Tj for an ambient temperature of 85°C with all outputs switching is: 85°C + 0.276W *81.2°C/W = 107.4°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 16 Lead TSSOP, Forced Convection θJA by Velocity Meters per Second Multi-Layer PCB, JEDEC Standard Test Boards ICS840272AGI REVISION A JULY 26, 2010 0 1 2.5 81.2°C/W 73.9°C/W 70.2°C/W 12 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Reliability Information Table 7. θJA vs. Air Flow Table for a 16 Lead TSSOP θJA vs. Air Flow Meters per Second Multi-Layer PCB, JEDEC Standard Test Boards 0 1 2.5 81.2°C/W 73.9°C/W 70.2°C/W Transistor Count The transistor count for ICS840272I: 3326 Package Outline and Package Dimensions Package Outline - G Suffix for 16 Lead TSSOP Table 8. Package Dimensions for 16 Lead TSSOP All Dimensions in Millimeters Symbol Minimum Maximum N 16 A 1.20 A1 0.5 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 4.50 e 0.65 Basic L 0.45 0.75 α 0° 8° aaa 0.10 Reference Document: JEDEC Publication 95, MO-153 ICS840272AGI REVISION A JULY 26, 2010 13 ©2010 Integrated Device Technology, Inc. ICS840272I Data Sheet SYNCHRONOUS ETHERNET FREQUENCY TRANSLATOR Ordering Information Table 9. Ordering Information Part/Order Number 840272AGILF 840272AGILFT Marking 40272AIL 40272AIL Package “Lead-Free” 16 Lead TSSOP “Lead-Free” 16 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. ICS840272AGI REVISION A JULY 26, 2010 14 ©2010 Integrated Device Technology, Inc. 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