ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR FOR WIRELESS INFRASTRUCTURE EQUIPMENT General Description Features The ICS813078I is a member of the HiperClocks family of high performance clock solutions from IDT. HiPerClockS™ The ICS813078I a PLL based synchronous clock solution that is optimized for wireless infrastructure equipment where frequency translation and jitter attenuation is needed. • Nine outputs, organized in three independent output banks with differential LVPECL and single-ended outputs • One differential input clock can accept the following differential input levels: LVDS, LVPECL, LVHSTL • • • One single-ended clock input • Internal Femtoclock frequency multiplier stage eliminates the need for an expensive external high frequency VCXO • • LVCMOS levels for all control I/O • RMS phase jitter @ 61.44MHz, using a 30.72MHz crystal (12kHz to 20MHz): 0.97ps rms (typical) • VCXO PLL bandwidth can be optimized for jitter attenuation and reference frequency tracking using external loop filter components • • • • • • PLL fast-lock control ICS The device contains two internal PLL stages that are cascaded in series. The first PLL stage attenuates the reference clock jitter by using an internal or external VCXO circuit. The internal VCXO requires the connection of an external inexpensive pullable crystal (XTAL) to the ICS813078I. This first PLL stage (VCXO PLL) uses external passive loop filter components which are used to optimize the PLL loop bandwidth and damping characteristics for the given application. The output of the first stage VCXO PLL is a stable and jitter-tolerant 30.72MHz reference input for the second PLL stage. The second PLL stage provides frequency translation by multiplying the output of the first stage up to 491.52MHz or 614.4MHz. The low phase noise characteristics of the VCXO-PLL clock signal is maintained by the internal FemtoClock™PLL, which requires no external components or complex programming. Two independently configurable frequency dividers translate the internal VCO signal to the desired output frequencies. All frequency translation ratios are set by device configuration pins. Supported input reference clock frequencies: 10MHz, 12.8MHz, 15MHz, 15.36MHz, 20MHz, 30.72MHz, 61.44MHz, and 122.88MHz Frequency generation optimized for wireless infrastructure Attenuates the phase jitter of the input clock signal by using low-cost pullable fundamental mode crystal (XTAL) RMS phase jitter @ 122.88MHz, using a 30.72MHz crystal (12kHz to 20MHz): 1.1ps rms (typical) PLL lock detect output Absolute pull range is +/-50 ppm Full 3.3V supply voltage -40°C to 85°C ambient operating temperature Available in lead-free (RoHS 6) package CLK1 REF_SEL nMR CLK0 nCLK0 VEE NA1 FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 1 nc 15 34 16 33 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 NB0 NC1 NC0 R2 R1 R0 BYPASS1 BYPASS0 nc nc NA0 NB1 nc nc VCCO nQA0 QA0 VEE nQA1 QA1 VCCO nQA2 QA2 VCC VEE nQB0 QB0 VCCO nQB1 FLM VCC VCC 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 3 46 4 45 5 44 6 43 64-Lead TQFP, E-Pad 7 42 10mm x 10mm x 1mm 8 41 package body 9 40 Y Package 10 39 11 38 12 37 13 36 14 35 1 2 VCCA nSTOPA nSTOPB nSTOPC QB1 ISET nc QC1 VEE QC2 VCCO_CMOS QC3 VEE VEE XTAL__IN XTAL_OUT LF1 LF0 VCC MF LOCK VEE QC0 VCCO_CMOS Pin Assignment Supported output clock frequencies: 30.72MHz, 38.4MHz, 61.44MHz, 76.8MHz, 122.88MHz, 153.6MHz, 245.76MHz, 491.52MHz, and 614.4MHz ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Block Diagram LF1 ISET LF0 XTAL_IN XTAL_OUT fXTAL = 30.72MHz LOCK nSTOPA fOUT fREF CLK0 nCLK0 CLK1 00 P ÷1, ÷2, ÷4, ÷5, ÷125 1 R[2:0] fVCXO fPD PD CP Femto PLL VCXO ÷16, ÷20 3 LUT Internal VCXO QA1 nQA1 QA2 nQA2 fVCO MV ÷1, ÷2, ÷12, ÷192, ÷256, ÷384 REF_SEL 11 10 NA ÷2, ÷4 ÷5, ÷8 QA0 nQA0 0x NB ÷1, ÷4 ÷5, ÷8 QB0 nQB0 QB1 nQB1 Multiplier FLM MF BYPASS[1:0] 2 nSTOPB QC0 NC ÷4, ÷5, ÷8, ÷16 QC1 QC2 NA[1:0] NB[1:0] QC3 NC[1:0] nMR nSTOPC FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 2 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Table 1. Pin Descriptions Number Name Type 1 LF1 Analog Input Input from external loop filter. VCXO control voltage input. 2 LF0 Analog Output Output to external loop filter. Charge pump output. 3 ISET Analog Charge pump current-settings pin. 4, 25, 26, 47, 48, 49 nc Unused No connect. 5 FLM Input 6, 7, 37, 61 VCC Power 8 CLK1 Input Pulldown Description VCXO-PLL fast lock mode. See Table 3H. LVCMOS/LVTTL interface levels. Power supply pins for LVPECL outputs. Pulldown Single-ended reference clock input. LVCMOS/LVTTL interface levels. Selects the input reference clock. See Table 3F. LVCMOS/LVTTL interface levels. 9 REF_SEL Input Pulldown 10 nMR Input Pullup 11 CLK0 Input Pulldown Non-inverting differential clock input. 12 nCLK0 Input Pullup/ Pulldown Inverting differential clock input. 13, 36, 43, 50, 54, 58, 64 VEE Power 14. 15 NA1, NA0 Input Pulldown Femto-PLL output-divider for QAn/nQAn outputs. See Table 3B. LVCMOS/LVTTL interface levels. 16, 17 NB1, NB0 Input Pulldown Femto-PLL output-divider for QBn/nQBn outputs. See Table 3C. LVCMOS/LVTTL interface levels. 18, 19 NC1, NC0 Input Pulldown Femto-PLL output-divider for QCn outputs. See Table 3D. LVCMOS/LVTTL interface levels. 20, 21, 22 R2, R1, R0 Input Pulldown VCXO-PLL pre-divider and VCXO multiplier selection. See Table 3A. LVCMOS/LVTTL interface levels. 23, 24 BYPASS1, BYPASS0 Input Pullup 27 VCCA Power 28 nSTOPA Input Pullup Output clock stop for Bank A. See Table 3J. LVCMOS/LVTTL interface levels. 29 nSTOPB Input Pullup Output clock stop for Bank B. See Table 3K. LVCMOS/LVTTL interface levels. 30 nSTOPC Input Pullup Output clock stop for Bank C. See Table 3L. LVCMOS/LVTTL interface levels. 31, 32 QB1, nQB1 Output Bank B output pair. LVPECL interface levels. 33, 40, 46 VCCO Power Output supply pins for LVPECL outputs. 34, 35 QB0, nQB0 Output Bank B output pair. LVPECL interface levels. 38, 39 QA2, nQA2 Output Differential Bank A output pair. LVPECL interface levels. 41, 42 QA1, nQA1 Output Differential Bank A output pair. LVPECL interface levels. 44, 45 QA0, nQA0 Output Differential Bank A output pair. LVPECL interface levels. Master reset. See Table 3I. LVCMOS/LVTTL interface levels. Negative supply pins. PLL mode selections. See Table 3G. LVCMOS/LVTTL interface levels. Analog supply pin. continued on next page. FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 3 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Number Name Type Description 51, 53, 55, 57 QC3, QC2, QC1, QC0 Output Single-ended Bank C outputs. LVCMOS/LVTTL interface levels. 52, 56 VCCO_CMOS Power Output supply pins for LVCMOS outputs. 59 LOCK Output VCXO lock state. LVCMOS/LVTTL interface levels. See Table 3M. 60 MF Input 62, 63 XTAL_OUT, XTAL_IN Input Pulldown FemtoClock-PLL feedback divider selection. See Table 3E. LVCMOS/LVTTL interface levels. Internal VCXO crystal oscillator interface. XTAL_IN is the input. XTAL_OUT is the output. 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 CIN Input Capacitance CPD Power Dissipation Capacitance (per output) RPULLUP Input Pullup Resistor Minimum Typical Maximum Units 4 pF 10 pF 51 kΩ RPULLDOWN Input Pulldown Resistor 51 kΩ ROUT 15 Ω Output Impedance VCC = VCCO_CMOS = 3.465V QC[3:0] DEVICE CONFIGURATION Table 3A. Input Frequency Configuration Example Table (fVCXO = 30.72MHz) The ICS813078I is a two stage device, a VCXO-PLL stage followed by a low phase noise FemtoClock PLL multiplier stage. The VCXO-PLL stage uses a pullable crystal to lock to the reference clock. The low phase noise FemtoClock multiplies the VCXO-PLL output clock up to 491.52MHz or 614.4MHz and three independent output dividers scale the frequency down to the desired output frequencies. With a given input and VCXO frequency, the output frequency is a function of the P, MF, MV and the NA, NB and NC dividers. The P and MV are controlled by the R[2:0] control pins through the internal lookup table (LUT). The VCXO-PLL pre-divider (P) down-scales the input reference frequency fREF and enables the use of the ICS813078I at a variety of input frequencies. P and MV must be set to match the VCXO frequency: fREF ÷ P = fVCXO ÷ MV. For example, at the nominal VCXO frequency of 30.72MHz and if MV equals one, the input frequency must be an integer multiple of 30.72MHz (for MV = 2, the input frequency must be an integer multiple of 15.36MHz). The FemtoClock PLL stage multiplies the VCXO frequency (30.72MHz) to 614.4MHz or 491.52MHz by a multiplier MF of 20 or 16. The output frequency equals [(fREF ÷ P) * MV * MF] ÷ NA, NB, or NC. The NA, NB and NC dividers operate independently. FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 4 Input Internal Dividers fref (MHz) R[2:0] P MV fXTAL (MHz) 30.72 000 1 1 30.72 61.44 001 2 1 30.72 122.88 010 4 1 30.72 15.36 011 1 2 30.72 10 100 125 384 30.72 12.8 101 5 12 30.72 15 110 125 256 30.72 20 111 125 192 30.72 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Table 3B. PLL Output-Divider (NA) Configuration Table. Inputs QAn Output Frequency (MHz) Output-Divider NA Operation NA1 NA0 MF = 0 MF = 1 0 (default) 0 (default) 2 fQAn = fVCO ÷ 2 245.76 307.2 0 1 4 fQAn = fVCO ÷ 4 122.88 153.6 1 0 5 fQAn = fVCO ÷ 5 98.304 122.88 1 1 8 fQAn = fVCO ÷ 8 61.44 76.8 Table 3C. PLL Output-Divider (NB) Configuration Table. Inputs QBn Output Frequency (MHz) Output-Divider NB Operation NB1 NB0 MF = 0 MF = 1 0 (default) 0 (default) 1 fQBn = fVCO ÷ 1 491.52 614.4 0 1 4 fQBn = fVCO ÷ 4 122.88 153.6 1 0 5 fQBn = fVCO ÷ 5 98.304 122.88 1 1 8 fQBn = fVCO ÷ 8 61.44 76.8 Table 3D. PLL Output-Divider (NC) Configuration Table. Inputs QCn Output Frequency (MHz) Output-Divider NC Operation NC1 NC0 MF = 0 MF = 1 0 (default) 0 (default) 4 fQCn = fVCO ÷ 4 122.08 153.6 0 1 5 fQCn = fVCO ÷ 5 98.304 122.88 1 0 8 fQCn = fVCO ÷ 8 61.44 76.8 1 1 16 fQCn = fVCO ÷ 16 30.72 38.4 Table 3E. Femtoclock PLL Feedback Divider (MF) Configuration Table (fXTAL = 30.72MHz) Input MF Feedback Divider MF Operation 0 (default) 16 fVCO = fVCXO x 16 = 491.52MHz 1 20 fVCO = fVCXO x 20 = 614.4MHz FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 5 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Table 3F. Input Reference Clock Multiplexer (REF_SEL) Configuration Table Input REF_SEL Operation 0 (default) Selects CLK0, nCLK0 differential input pair as reference frequency. 1 Selects CLK1 single-ended input as reference frequency. The input reference selector should be tied to logic 0, selecting the differential clock inputs, for best signal integrity and lowest phase noise Table 3G. PLL Bypass (BYPASS) Configuration Table Input BYPASS1 BYPASS0 Operation 0 X fOUT = ((fREF ÷ P) * MV * MF) ÷ NA, NB, or NC. VCXO-PLL operation, jitter attenuation and frequency multiplication enabled. 1 0 fOUT = ((fREF ÷ P) * MV) ÷ NA, NB, or NC. VCXO-PLL enabled, Femto-PLL bypassed. Jitter attenuation (VCXO-PLL) enabled. AC specifications do not apply. 1 (default) 1 (default) fOUT = fREF ÷ NA, NB, or NC. VCXO-PLL and Femto-PLL bypassed, no jitter attenuation and frequency multiplication. AC specifications do not apply. The BYPASS[1:0] controls should be set to logic LOW level for normal operation. BYPASS = 1x enables the PLL bypass mode for factory test. In PLL Bypass Mode, the output frequency is divided by NA, NB, or NC dividers. Table 3H. Fast Lock Mode (FLM) Configuration Table Input FLM 0 (default) 1 Operation Normal operation. Fast PLL lock operation. Use this mode only during startup to decrease PLL lock time. VCC = 3.3V 0V tLOCK VCXO-PLL Acquires Lock VCXO-PLL Locked LOCK FLM Fast Lock Mode (High VCXO-PLL Bandwidth) Nominal VCXO-PLL Bandwidth Figure 1. Recommended Start-up Timing Diagram FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 6 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Table 3I. Reset (nMR) Configuration Table Input nMR Operation 0 The Femto-PLL is reset. 1 (default) Normal operation. Table 3J. Output Disable (nSTOPA) Configuration Table. Input nSTOPA 0 1 (default) Operation QA[2:0]/nQA[2:0] outputs are stopped in logic LOW state. The assertion of nSTOPA is asynchronous to the internal clock signal and may cause an output runt pulse. Normal operation and outputs enabled. Table 3K. Output Disable (nSTOPB) Configuration Table. Input nSTOPB 0 1 (default) Operation QB[1:0] / nQB[1:0] outputs are stopped in logic LOW state. The assertion of nSTOPB is asynchronous to the internal clock signal and may cause an output runt pulse. Normal operation and outputs enabled. Table 3L. Output Disable (nSTOPC) Configuration Table. Input nSTOPC 0 1 (default) Operation QC[3:0] outputs are stopped in logic LOW state. The assertion of nSTOPC is asynchronous to the internal clock signal and may cause an output runt pulse. Normal operation and outputs enabled. Table 3M. PLL Lock Status Output (LOCK_DT) Configuration Table. Output Conditions Locked Unlocked LOCK_DT Constantly HIGH. HIGH with occasional LOW pulses. FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 7 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 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, VCC 4.6V Inputs, VI -0.5V to VCC + 0.5V Outputs, IO (LVPECL) Continuous Current Surge Current 50mA 100mA Outputs, VO (LVCMOS) -0.5V to VCCO_CMOS+ 0.5V Package Thermal Impedance, θJA 31.8°C/W (0 mps) Storage Temperature, TSTG -65°C to 150°C DC Electrical Characteristics Table 4A. Power Supply DC Characteristics, VCC = VCCO = VCCO_CMOS = 3.3V ± 5%, TA = -40°C to 85°C Symbol Parameter VCC Core Supply Voltage VCCA Analog Supply Voltage Test Conditions VCCO, Output Supply Voltage VCCO_CMOS Minimum Typical Maximum Units 3.135 3.3 3.465 V VCC – 0.15 3.3 VCC V 3.135 3.3 3.465 V IEE Power Supply Current 260 mA ICCA Analog Supply Current 15 mA ICCO_CMOS Output Supply Current 6 mA FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 8 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Table 4B. LVCMOS/LVTTL DC Characteristics, VCC = VCCO_CMOS = 3.3V ± 5%, TA = -40°C to 85°C Symbol Parameter VIH Input High Voltage VIL Input Low Voltage IIH IIL Input High Current Input Low Current Test Conditions Minimum Typical Maximum Units 2 VCC + 0.3 V -0.3 0.8 V CLK1, REF_SEL, MF, FLM, NA[1:0], NB[1:0], NC[1:0], R[2:0] VCC = VIN = 3.465V 150 µA nSTOP[A:C], BYPASS[1:0], nMR VCC = VIN = 3.465V 10 µA CLK1, REF_SEL, MF, FLM, NA[1:0], NB[1:0], NC[1:0], R[2:0] VCC = 3.465V, VIN = 0V -10 µA nSTOP[A:C], BYPASS[1:0], nMR VCC = 3.465V, VIN = 0V -150 µA 2.6 V VOH Output High Voltage QC0:QC3 IOH = -12mA VOL Output Low Voltage QC0:QC3 IOL = 12mA 0.5 V Maximum Units 150 µA Table 4C. Differential DC Characteristics, VCC = VCCO = 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 CLK0, nCLK0 Minimum Typical VCC = VIN = 3.465V CLK0 VCC = 3.465V, VIN = 0V -10 µA nCLK0 VCC = 3.465V, VIN = 0V -150 µA 0.15 1.3 V VEE + 0.5 VCC – 0.85 V NOTE 1: VIL should not be less than -0.3V. NOTE 2: Common mode input voltage is defined as VIH. Table 4D. LVPECL DC Characteristics, VCC = VCCO = 3.3V ± 5%, TA = -40°C to 85°C Symbol Parameter VOH Output High Voltage; NOTE 1 VOL Output Low Voltage; NOTE 1 VSWING Peak-to-Peak Output Voltage Swing Test Conditions Minimum Typical Maximum Units VCCO – 1.4 VCCO – 0.9 V VCCO – 2.0 VCCO – 1.7 V 0.6 1.0 V NOTE 1: Outputs termination with 50Ω to VCCO – 2V. FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 9 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR AC Electrical Characteristics Table 5. AC Characteristics, VCC = VCCO = VCCO_CMOS = 3.3V ± 5%, TA = -40°C to 85°C Symbol fREF fOUT Parameter Test Conditions Minimum R=000 30.72MHz–50ppm 30.72MHz+50ppm R=001 61.44MHz–50ppm 61.44MHz+50ppm R=010 122.88MHz–50ppm 122.88MHz+50ppm R=011 15.36MHz–50ppm 15.36MHz+50ppm R=100 10MHz–50ppm 10MHz+50ppm R=101 12.88MHz–50ppm 12.88MHz+50ppm R=110 15MHz–50ppm 15MHz+50ppm R=111 20MHz–50ppm Input Reference Frequency Output Frequency VCXO-PLL VCO Lock Range fVCO Femto-PLL VCO Lock Range tjit(Ø) RMS Phase Jitter Integration Range: 12kHz - 20MHz; NOTE 1 Period Jitter MF=0, N=2 245.76 MHz MF=0, N=4 122.88 MHz MF=0, N=5 98.304 MHz MF=0, N=8 61.44 MHz MF=0, N=16 30.72 MHz MF=1, N=1 614.4 MHz MF=1, N=2 307.2 MHz MF=1, N=4 153.6 MHz MF=1, N=5 122.88 MHz MF=1, N=8 76.8 MHz 38.4 30.72MHz–50ppm MHz 30.72MHz+50ppm 491.52, 614.4 MHz 491.52MHz 1.03 ps QAn, QBn 153.6MHz, MF=20 0.92 ps QAn, QBn 122.88MHz, MF=20 1.1 ps QAn, QBn 122.88MHz, MF=16 1.1 ps QAn, QBn 61.44MHz, MF=16 0.97 ps QAn QBn 153.6MHz, QCn = off 122.88MHz, QCn = off 35 ps QAn, QBn 122.88MHz, QCn = off 30 ps 100Hz offset ΦN 20MHz+50ppm MHz 10Hz offset Single-Side Band Noise at: QAn =122.88MHz Units 491.52 QBn tjit(per) Maximum MF=0, N=1 MF=1, N=16 fVCXO Typical 1kHz offset -41.3 30.72MHz XTAL, fref = 30.72MHz, 10kHz offset 100kHz offset QBn and QCn = 122.88MHz 1MHz offset dBc/Hz -71.5 dBc/Hz -100.7 dBc/Hz -127.2 dBc/Hz -128.2 dBc/Hz -131.4 dBc/Hz continued on next page FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 10 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Symbol Parameter Test Conditions Minimum 10Hz offset 100Hz offset ΦN Single-Side Band Noise at: QAn = 61.44MHz 1kHz offset 30.72MHz XTAL, fref = 30.72MHz, 10kHz offset 100kHz offset QBn and QCn = 61.44MHz 1MHz offset tsk(o) Output Skew NOTE 2, 3 tsk(b) Bank Skew; NOTE 2, 4 tR / tF Output Rise/ Fall Time Output Duty Cycle Maximum Units -44.6 dBc/Hz -77.2 dBc/Hz -106.4 dBc/Hz -132.8 dBc/Hz -132.9 dBc/Hz -137.9 dBc/Hz fQA = fQB across QAn and QBn 200 ps fQA ≠ fQB across QAn and QBn 300 ps QAn/nQAn 50 ps QBn/nQBn 50 ps QCn 65 ps QAn/nQAn 20% to 80% 100 600 ps QBn/nQBn 20% to 80% 100 600 ps QCn 20% to 80% 350 1050 ps 47 53 % QAn/nQAn odc Typical QBn/nQBn N≠1 47 53 % QBn/nQBn N=1 43 57 % 45 55 % QCn NOTE: TA, Ambient Temperature applied using forced air flow. NOTE 1: Phase jitter measured using a 30.72MHz quartz crystal. NOTE 2: This parameter is defined in accordance with JEDEC Standard 65. NOTE 3: Defined as skew between outputs at the same supply voltage and with equal load conditions. Measured at the output differential cross points. NOTE 4: Defined as skew within a bank of outputs at the same voltage and with equal load conditions. FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 11 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR ➝ Typical Phase Noise at 61.44MHz Filter ➝ Raw Phase Noise Data ➝ Noise Power dBc Hz 61.44MHz RMS Phase Jitter (Random) 12kHz to 20MHz = 0.97ps (typical) Phase Noise Result by adding a filter to raw data Offset Frequency (Hz) FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 12 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR ➝ Typical Phase Noise at 122.88MHz Filter ➝ Noise Power dBc Hz 122.88MHz RMS Phase Jitter (Random) 12kHz to 20MHz = 1.1ps (typical) ➝ Raw Phase Noise Data Phase Noise Result by adding a filter to raw data Offset Frequency (Hz) FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 13 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Parameter Measurement Information 1.65V±5% 1.65V±5% 1.65V±5% 1.65V±5% VCC, Qx VCCO SCOPE SCOPE VCC, VCCO_CMOS VCCA VCCA Qx LVCMOS LVPECL nQx VEE VEE -1.65V±5% -1.65V±5% 3.3V LVPECL Output Load AC Test Circuit 3.3V LVCMOS Output Load AC Test Circuit Phase Noise Plot Noise Power VCC nCLK0 V PP V Cross Points Phase Noise Mask CMR CLK0 f1 VEE Offset Frequency f2 RMS Jitter = Area Under the Masked Phase Noise Plot Differential Input Level RMS Phase Jitter VOH nQx VREF VOL 1σ contains 68.26% of all measurements 2σ contains 95.4% of all measurements 3σ contains 99.73% of all measurements 4σ contains 99.99366% of all measurements 6σ contains (100-1.973x10-7)% of all measurements Reference Point (Trigger Edge) Qx nQy Qy tsk(o) Histogram Mean Period (First edge after trigger) Period Jitter FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Differential Output Skew 14 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Parameter Measurement Information, continued nQXn VCCO 2 QCn QXn nQXn VCCO 2 QCn QXn tsk(b) tsk(b) Where X = Bank QAn or Bank QBn LVCMOS Bank Skew Differential Bank Skew nQA0:nQA2. nQB0, nQB1 nQXn QA0:QA2. QB0, QB1 QXn t PW t VCCO/2 QCn odc = tsk(bk-bk) PERIOD t PW x 100% t PERIOD Where X = Bank QAn or Bank QBn Output Rise/Fall Time Differential Output Duty Cycle/Pulse Width/Period QC0:QC3 t PW t odc = PERIOD t PW x 100% t PERIOD LVCMOS Output Duty Cycle/Pulse Width/Period FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 15 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Application Information capacitance, the VCXO will oscillate at a lower frequency than the crystal specification. In either case, the absolute tuning range is reduced. The correct value of CL is dependant on the characteristics of the VCXO. The recommended CL in the Crystal Parameter Table balances the tuning range by centering the tuning curve. VCXO-PLL EXTERNAL COMPONENTS Choosing the correct external components and having a proper printed circuit board (PCB) layout is a key task for quality operation of the VCXO-PLL. In choosing a crystal, special precaution must be taken with the package and load capacitance (CL). In addition, frequency, accuracy and temperature range must also be considered. Since the pulling range of a crystal also varies with the package, it is recommended that a metal-canned package like HC49 be used. Generally, a metal-canned package has a larger pulling range than a surface mounted device (SMD). For crystal selection information, refer to the VCXO Crystal Selection Application Note. The VCXO-PLL Loop Bandwidth Selection Table shows RS, CS and CP values for recommended high, mid and low loop bandwidth configurations. The device has been characterized using these parameters. For other configurations, refer to the Loop Filter Component Selection for VCXO Based PLLs Application Note. The crystal and external loop filter components should be kept as close as possible to the device. Loop filter and crystal traces should be kept short and separated from each other. Other signal traces should be kept separate and not run underneath the device, loop filter or crystal components. The crystal’s load capacitance CL characteristic determines its resonating frequency and is closely related to the VCXO tuning range. The total external capacitance seen by the crystal when installed on a board is the sum of the stray board capacitance, IC package lead capacitance, internal varactor capacitance and any installed tuning capacitors (CTUNE). LF0 LF1 ISET RS CP RSET CS XTAL_IN CTUNE 30.72MHz If the crystal CL is greater than the total external capacitance, the VCXO will oscillate at a higher frequency than the crystal specification. If the crystal CL is lower than the total external XTAL_OUT CTUNE VCXO Characteristics Table Symbol Parameter Typical Units kVCXO VCXO Gain 9.3 kHz/V CV_LOW Low Varactor Capacitance 14.7 pF CV_HIGH High Varactor Capacitance 7.5 pF VCXO-PLL Loop Bandwidth Selection Table Bandwidth Crystal Frequency (MHz) MV RS (kΩ) CS (µF) CP (µF) RSET (kΩ) 8.5Hz (Low) 30.72 384 20 10 0.1 10 85Hz (Mid) 30.72 192 20 10 0.01 2.0 22.2kHz (High) 30.72 1 30 0.01 0.00001 2.2 Crystal Characteristics Symbol Parameter Test Conditions Minimum Mode of Oscillation fN Frequency fT Frequency Tolerance fS Frequency Stability Typical Maximum Units Fundamental 30.72 Operating Temperature Range -40 MHz ±20 ppm ±20 ppm +85 0C CL Load Capacitance 10 pF CO Shunt Capacitance 4 pF CO / C1 Pullability Ratio ESR Equivalent Series Resistance 20 Ω Drive Level 1 mW ±3 per year ppm 220 Aging @ 25 0C FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 16 240 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 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 = VCC/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 VCC = 3.3V, V_REF should be 1.25V and R2/R1 = 0.609. VCC R1 1K Single Ended Clock Input CLK V_REF nCLK C1 0.1u R2 1K Figure 2. Single-Ended Signal Driving Differential Input 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 ICS813078I provides separate power supplies to isolate any high switching noise from the outputs to the internal PLL. VCC, VCCA, VCCO and VCCO_CMOS should be individually connected to the power supply plane through vias, and 0.01µF bypass capacitors should be used for each pin. Figure 3 illustrates this for a generic VCC pin and also shows that VCCA requires that an additional 10Ω resistor along with a 10µF bypass capacitor be connected to the VCCA pin. FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 3.3V VCC .01µF 10Ω .01µF 10µF VCCA Figure 3. Power Supply Filtering 17 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Differential Clock Input Interface The CLK /nCLK accepts LVDS, LVPECL, LVHSTL, SSTL, HCSL and other differential signals. Both VSWING and VOH must meet the VPP and VCMR input requirements. Figures 4A to 4F 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 4A, 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 4A. HiPerClockS CLK/nCLK Input Driven by an IDT Open Emitter HiPerClockS LVHSTL Driver Figure 4B. 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 4C. HiPerClockS CLK/nCLK Input Driven by a 3.3V LVPECL Driver 2.5V nCLK Zo = 50Ω Receiver LVDS Figure 4D. 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 4F. HiPerClockS CLK/nCLK Input Driven by a 2.5V SSTL Driver Figure 4E. HiPerClockS CLK/nCLK Input Driven by a 3.3V HCSL Driver FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 18 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Recommendations for Unused Input and Output Pins Inputs: Outputs: CLK/nCLK Inputs LVPECL Outputs 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. All unused LVPECL outputs can be left floating. We recommend that there is no trace attached. Both sides of the differential output pair should either be left floating or terminated. LVCMOS Outputs CLK Input All unused LVCMOS output can be left floating. There should be no trace attached. For applications not requiring the use of a clock input, it can be left floating. Though not required, but for additional protection, a 1kΩ resistor can be tied from the CLK input 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. Termination for 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. transmission lines. Matched impedance techniques should be used to maximize operating frequency and minimize signal distortion. Figures 5A and 5B 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 50W 3.3V Zo = 50Ω 125Ω FOUT FIN 125Ω Zo = 50Ω Zo = 50Ω FOUT 50Ω 1 RTT = Z ((VOH + VOL) / (VCC – 2)) – 2 o FIN 50Ω Zo = 50Ω VCC - 2V RTT 84Ω Figure 5A. 3.3V LVPECL Output Termination FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 84Ω Figure 5B. 3.3V LVPECL Output Termination 19 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR EPAD Thermal Release Path In order to maximize both the removal of heat from the package and the electrical performance, a land pattern must be incorporated on the Printed Circuit Board (PCB) within the footprint of the package corresponding to the exposed metal pad or exposed heat slug on the package, as shown in Figure 6. The solderable area on the PCB, as defined by the solder mask, should be at least the same size/shape as the exposed pad/slug area on the package to maximize the thermal/electrical performance. Sufficient clearance should be designed on the PCB between the outer edges of the land pattern and the inner edges of pad pattern for the leads to avoid any shorts. application specific and dependent upon the package power dissipation as well as electrical conductivity requirements. Thus, thermal and electrical analysis and/or testing are recommended to determine the minimum number needed. Maximum thermal and electrical performance is achieved when an array of vias is incorporated in the land pattern. It is recommended to use as many vias connected to ground as possible. It is also recommended that the via diameter should be 12 to 13mils (0.30 to 0.33mm) with 1oz copper via barrel plating. This is desirable to avoid any solder wicking inside the via during the soldering process which may result in voids in solder between the exposed pad/slug and the thermal land. Precautions should be taken to eliminate any solder voids between the exposed heat slug and the land pattern. Note: These recommendations are to be used as a guideline only. For further information, refer to the Application Note on the Surface Mount Assembly of Amkor’s Thermally/Electrically Enhance Leadfame Base Package, Amkor Technology. While the land pattern on the PCB provides a means of heat transfer and electrical grounding from the package to the board through a solder joint, thermal vias are necessary to effectively conduct from the surface of the PCB to the ground plane(s). The land pattern must be connected to ground through these vias. The vias act as “heat pipes”. The number of vias (i.e. “heat pipes”) are SOLDER PIN PIN PAD EXPOSED HEAT SLUG GROUND PLANE THERMAL VIA SOLDER PIN LAND PATTERN (GROUND PAD) SOLDER PIN PAD Figure 6. Assembly for Exposed Pad Thermal Release Path - Side View (drawing not to scale) FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 20 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Power Considerations This section provides information on power dissipation and junction temperature for the ICS813078I. Equations and example calculations are also provided. 1. Power Dissipation. The total power dissipation for the ICS813078I 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. Core and LVPECL Output Power Dissipation • Power (core)_MAX = VCC_MAX *IEE_MAX = 3.465V * 260mA = 900.9mW Power (output)_MAX = 30mW/Loaded Output Pair If all outputs are loaded, the total power is 5 * 30mW = 150mW LVCMOS Output Power Dissipation • Output Impedance ROUT Power Dissipation due to Loading 50Ω to VCCO/2 Output Current IOUT = VCCO_MAX / [2 * (50Ω + ROUT)] = 3.465V / [2 * (50Ω + 15Ω)] = 26.7mA • Power Dissipation on the ROUT per LVCMOS output Power (ROUT) = ROUT * (IOUT)2 = 15Ω * (26.7mA)2 = 10.7mW per output • Total Power Dissipation on the ROUT Total Power (ROUT) = 10.7mW * 4 = 42.8mW • Dynamic Power Dissipation at 153.6MHz Power (25MHz) = CPD * Frequency * (VCCO)2 = 10pF * 153.6MHz * (3.465V)2 = 18mW per output Total Power (153.6MHz) = 18mW * 4 = 72mW Total Power Dissipation • Total Power = Power (core) + Power (LVPECL output) + Total Power (ROUT) + Total Power (153.6MHz) = 900.9mW + 150mW + 42.8mW + 72mW = 1165.7mW FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 21 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 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 31.8°C/W per Table 6 below. Therefore, Tj for an ambient temperature of 85°C with all outputs switching is: 85°C + 1.166W * 31.8°C/W = 122.1°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 64 Lead TQFP, E-Pad Forced Convection θJA Vs. Air Flow Meters per Second Multi-Layer PCB, JEDEC Standard Test Boards FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 0 1 2.5 31.8°C/W 25.8°C/W 24.2°C/W 22 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Reliability Information Table 7. θJA vs. Air Flow Table for a 64 Lead TQFP, E-Pad θJA vs. Air Flow Linear Feet per Minute Multi-Layer PCB, JEDEC Standard Test Boards 0 1 2.5 31.8°C/W 25.8°C/W 24.2°C/W Transistor Count The transistor count for ICS813078I is: 6235 FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 23 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Package Outline and Package Dimensions Package Outline - Y Suffix for 64 Lead TQFP, E-Pad -HD VERSION EXPOSED PAD DOWN Table 8. Package Dimensions for 64 Lead TQFP, E-Pad Symbol N A A1 A2 b c D&E D1 & E1 D2 & E2 D3 & E3 e L θ ccc JEDEC Variation: ACD All Dimensions in Millimeters Minimum Nominal Maximum 64 1.20 0.05 0.10 0.15 0.95 1.00 1.05 0.17 0.22 0.27 0.09 0.20 12.00 Basic 10.00 Basic 7.50 Ref. 4.5 5.0 5.5 0.50 Basic 0.45 0.60 0.75 0° 7° 0.08 Reference Document: JEDEC Publication 95, MS-026 FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 24 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR Ordering Information Table 9. Ordering Information Part/Order Number Marking Package Shipping Packaging Temperature 813078BYILF ICS813078BYILF “Lead-Free” 64 Lead TQFP, E-Pad Tray -40°C to +85°C 813078BYILFT ICS813078BYILF “Lead-Free” 64 Lead TQFP, E-Pad 500 Tape & Reel -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. FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 25 ICS813078BYI REV. A OCTOBER 6, 2008 ICS813078I FEMTOCLOCKS™ VCXO-PLL FREQUENCY GENERATOR 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) © 2008 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