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Think of Frequency Think of Introduction to Crystal www.txccorp.com TXC Confidential & Proprietary | 1
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TXC Confidential & Proprietary | 2 Quartz Crystal Basic: Structure 33 45 67 21 00 79 67 45 12 21 45 67 33 88 55 79 00 88 79 00 88 Silicon Oxygen Domain Wall X Y Z Constitutes : Silicon Dioxide, SiO 2 Crystal System : Trigonal 32 Melting Point : ~ 1,750 degree C @ 1 atm Hardness : ~ 7.2 Mohs @ 1 atm Nature QuartzSynthetic Quartz
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TXC Confidential & Proprietary | 3 Si 4+ O 2- Si 4+ O 2- - -- - + ++ + Si 4+ O 2- + ++ + - -- - - Piezoelectric Effect - Reverse Piezoelectric Effect Si 4+ O 2- Electric neutral When a pulling-outward force is applied on O 2-, a positive electric field is induced. When a pushing-inward force is applied on O 2-, a negative electric field is induced. Electric neutral - - - - - -- - - - - - Si 4+ O 2- + + + + + ++ + + + + + + + + + + ++ + + + + + - - - - - -- - - - - - - - - - - -- - - - - - - - - - - -- - - - - - + + + + + ++ + + + + + + + + + + ++ + + + + + Si 4+ O 2- When an electric field is applied, the induced electric filed is generated, and force the O 2- moving outward. When an electric field is applied, the induced electric filed is generated, and force the O 2- moving inward. Quartz Crystal Basic: Piezoelectricity
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TXC Confidential & Proprietary | 4 Natural Quartz Synthetic Quartz Quartz Crystal Basic: Natural vs. Synthetic
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TXC Confidential & Proprietary | 5 AUTOCLAVE HYDROTHERMAL METHOD RAW MATERIAL : Silica HIGH TEMPERATURE : ~ 350 ~ 400 ℃ HIGH PRESSURE : ~ 900 ~ 1,000 Kg / cm 2 HIGH TEMP. STABILITY : ± 3 ℃ LONG GROWTH TIME : 1 ~ 6 Month HIGH PURITY Infra-Red Absorption (IRA) : 3585 CM -1 Crystal Growth Region (~300 ℃ ) Dissolving Region (~400 ℃ ) Quartz Crystal Basic: Synthetic Quartz
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TXC Confidential & Proprietary | 6 Quartz Crystal Basic: Synthetic Quartz Grown quartz bars from autoclave Moving new autoclave to the factory
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TXC Confidential & Proprietary | 7 Wire Sawing Quartz Bar A123 456 789 0EN B C D Lapping 22.1372 Wafer Frequency Processing time: <10 days Manufacturing Process: From Bar to Blank
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TXC Confidential & Proprietary | 8 Low Frequency CT : +38 0 DT : -52 0 ET : +66 0 FT : -57 0 High Frequency AT : +35 0 12’ BT : -49 0 Many cutting angles for various applications. AT cutting is one of the most popular and applicable angles. Cutting Angle
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TXC Confidential & Proprietary | 9 Cutting Angle: FT Characteristic of Different Cuts 20 40 0 - 20 - 40 - 60 - 80 - 100 - 160 - 120 - 140 - 40- 20020406080 Frequency Change in ppm Temperature ( º C ) AT GT DT XY CT
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TXC Confidential & Proprietary | 10 Cutting Angle: AT-Cut FT Characteristic
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TXC Confidential & Proprietary | 11 Thickness of Blank: Determines Frequency Al AT Cut Crystal - Resonance frequency is determined by thickness of blank. - For a 20 MHz crystal, the thickness is around 83um. (The diameter of human hair is around 50~80um) - The thinner the blank, the higher the frequency is. Note : The constant of 1670 is not the exact number for AT cutting. This number ranges from 1650 ~ 1685 depends on the dimension and thickness of the AT quartz plate. Frequency
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TXC Confidential & Proprietary | 12 Structure and Manufacturing Process IC Die Bonding Wire Bonding Blank Cleaning Base Plating Frequency Adj. Final Testing Marking Taping Seam Sealing Mechanical Testing Blank Auto- Mounting Crystal Oscillator ■ 40.000 TXC CM211 ■ 24.576 TXC CN001 Crystal Metal Lid Plated Blank Ceramic Package (Bottom) Ceramic Package (Top) Oscillation IC Processing time: <10 days
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TXC Confidential & Proprietary | 13Specification Tips of Defining the Specification of a Crystal: 1. Determine the Nominal Frequency Ex: 8Z Series (2.5x2.0 mm) 2. Choose the Load Capacitance 3. Define the Frequency Tolerance and Stability 4. Define the Drivel Level, Effective Resistance, and Shunt capacitance C 0
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TXC Confidential & Proprietary | 14 Load Capacitance Choosing : C L vs. Trim Sensitivity Load Capacitance: 06~10 pF, high trim sensitivity: unstable, but tunable Load Capacitance: 16~30 pF, low trim sensitivity: stable, but hardly tunable Ex. 3.2 x 2.5mm, 12.0 MHz, CL=8.0 pF
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TXC Confidential & Proprietary | 15 Package Size vs Drive Level & Resistance Ex: 25MHz Crystal
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TXC Confidential & Proprietary | 16 Worldwide Lab Facilities Three FAE locations with RD level testing equipment for Oscillation Circuit/Oscillator When the assistance is needed, please contact account manager to arrange the test in different locations Ningbo, China Taoyuan, Taiwan San Jose, USA
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TXC Confidential & Proprietary | 17 Services Unit Analysis Crystal & Tuning Fork Electrical Testing (S&A 250B) SPICE Model (RLC Model) Oscillator Electrical Testing Testing Temperature : -73˚C ~175 ˚C Board Evaluation and Circuit Matching Accuracy of Frequency Drive Level Negative Resistance Start-up Time Operating Temperature Testing (Stability) Failure Part Analysis Initial FA report
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TXC Confidential & Proprietary | 18 Measuring Instruments and Test Equipment
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TXC Confidential & Proprietary | 19 Purpose of Matching Mismatched Circuit: Х None or inconsistent oscillation Х Long startup time Х Bad temperature performance Х Crystal resonator damaging Х Bad jitter and frequency error Х Others Measurements: Accuracy of Frequency Drive Level Negative Resistance Startup time Operating Temperature Test (Stability)
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Think of Frequency Think of Introduction to Crystal Oscillators www.txccorp.com TXC Confidential & Proprietary | 20
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TXC Confidential & Proprietary | 21 Crystal Oscillators 1.Least integrated circuitry inside IC 2. Best noise performance in LSI-based crystal oscillator 3.±15 PPM level temperature stability 4. ±10 PPM level frequency accuracy based on physical tuning capability Amplifier Buffer Crystal CdCd CgCg GND F out VDD Simple Packaged Crystal Oscillator (XO) Simple Packaged Crystal Oscillator (XO) No Voltage Tunable Capability
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TXC Confidential & Proprietary | 22 1.Integrated varactor inside IC 2. The tunable range of varactor and the load sensitivity of X'tal resonator influences the tunable range of VCXO 3.±15 PPM level temperature stability 4. ±10 PPM level frequency accuracy based on physical tuning capability Tunable Range over Temp. VC VC-plus VC-minus Amplifier Buffer (CMOS/Differenial) F out VDD Crystal CdCd CgCg Varactor VC GND Voltage-Controlled Crystal Oscillator (VCXO) Voltage-Controlled Crystal Oscillator (VCXO) Crystal Oscillators
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Tunable Range over Temp. TXC Confidential & Proprietary | 23 Amplifier Buffer F out VDD Crystal CdCd CgCg Varactor VC Temperature Sensor and Compensation Circuitry GND 1. Integrated varactor & compensation circuit inside IC 2. The tunable range of varactor and the load sensitivity of X'tal resonator influences the tunable range of VCXO 3. <±2.5 to ±0.28 (S3-TCXO)PPM level temperature stability 4. <±2.5 PPM level frequency accuracy based on physical tuning capability Temperature-Compensated Crystal Oscillator (TCXO) Temperature-Compensated Crystal Oscillator (TCXO) Crystal Oscillators 25 ̊C T F Crystal IC Compensated Result ≦ 2.5 ppm ≦ 0.3 ppm (Stratum 3 TCXO)
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TXC Confidential & Proprietary | 24 Oven Amplifier Buffer F out V dd Crystal CdCd CgCg Varactor VcVc Temperature Sensor Oven Control Circuit 1. Discrete electrical components & oven controlled circuit 2. The tunable range of varactor and the load sensitivity of X'tal resonator influences the tunable range of VCXO 3.<±0.1 PPM level temperature stability 4. <±0.1 PPM level frequency accuracy based on physical tuning capability Tunable Range over Temp. (Depends on crystal cut) Oven-Controlled Crystal Oscillator (OCXO) Oven-Controlled Crystal Oscillator (OCXO) Crystal Oscillators
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Less than 1/3 of CMOS voltage swing Less than 1/6 of CMOS voltage swing TXC Confidential & Proprietary | 25 Differential Output CMOS (Single-ended) Differential CMOS: Single-ended CMOS: Single-ended Differential * : Dual-ended (same frequency) Advantage of Differential Output Advantage of Differential Output Low voltage swing Better noise rejection *: 3 kinds of differential output that TXC is using: LVPECL, LVDS, HCSL
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TXC Confidential & Proprietary | 26 Thank you
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