Chip NTC Thermistor
Contents 1 Technical Information Microstructure and Conduction Mechanism NTC Type & working principle Terms and Description 2 Sunlord NTC Thermistor temperature sensor NTC Power NTC 3 Application
Microstructure and Conduction Mechanism Made of metal oxides of Mn, Co, Ni, Cu, etc; Spinal type structure; The same conduction mechanism like semiconducting material such as Ge, Si etc. ; At low temperature, The carrier concentratio in the material is very small, NTC shows a Characteristic of high resistance; As the temperature increases, The carrier concentratio rises therefore the resistance of NTC becomes lower.
Temperature Characteristics R T = R N expb(1/t 1/T N ) T: Rated Temperature( K ) R T :NTC resistance at Temperature T(K). R N :NTC resistance at rated Temperature T N (K). B: NTC B constant
Different types of NTC Thermistor According to different applications,there are two types of NTC thermistors: Temperature sensor NTC & Power NTC Type Temperature sensor NTC Power NTC Application temperature sensing, temperature control, and temperature compensation Rush Current Suppression Electrical feature Larger R25(several KΩ), lower operating current (several ma), requesting tight tolerance of R25 and B constant Smaller R25 (several Ω), bigger Permissible Current (several A), bigger thermal time constant & thermal dissipation constant
Working Method of Temperature sensor NTC Lay the NTC at the temperature sensing place and also make it connect the arm of bridge circuit. As NTC resistance changes with ambient temperature, when bridge unbalanced and a current would run across the Ammeter. The current signal can be processed digitally and showed as temperature. Measure bridge Application Circuit
Working Method of Temperature sensor NTC The inrush current occurs in power supply circuits (LED driver board, inverter fluorescent lamps, heaters, etc.) when electric equipment switches on. It will be hundred times higher than normal operating current. NTC resistance at room temperature is big enough to suppress inrush current when the equipment switches on. After that, as the body temperature of NTC rising, its resistance becomes smaller, and thus the power consumption of NTC is negligible to ensure electric equipment working normally.
Terms and Description R25: R25 refers to the DC resistance measured at a rated temperature (25 ) for an unloaded thermister. B-constant: It calculates between two specified ambient temperature by following formula. ln( R / R0 ) B = 1/ T 1/ T 0 T and T 0 is absolute temperature(k). MAX. Permissive Operating Current (temperature sensor NTC): The current that keep body temperature of chip NTC on the PC board in still air rising 1 C by self-heating. MAX. Permissible Current (Power NTC): The max continual current may be applied to the thermistor at a rated temperature(25 ). Residual Resistance (Power NTC): Residual Resistance (Power NTC): The max. resistance of NTC when applied Max. Permissible Current at the ambient temperature 25. It also called Max. Approximate Resistance.
Terms and Description Thermal Dissipation Constant δ : It shows necessary electric power that thermistor s temperature rises 1 by self heating. It calculates by the following formula: δ = W T T 0 Power is expressed in watts. The dissipation constant of a thermistor with a 0.095 O.D., coated with epoxy or phenolic, is typically 13mW/ in stirred oil and 2mW/ in still air. It shows necessary electric power that thermistor s temperature rises 1 by self heating. It calculates by the following formula: Power is expressed in watts. The dissipation constant of a thermistor with a 0.095 O.D., coated with epoxy or phenolic, is typically 13mW/ in stirred oil and 2mW/ in still air. Max. Permissive Capacitance The max permissive capacitance may be connected to the thermistor under rated voltage.
Terms and Description Rated Electric Power P : Rated Electric Power P is the maximum power an NTC thermistor is capable of handling at a particular ambient temperature with its own temperature not exceeding the maximum operating temperature. Thermal Time Constant τ : The total time for the temperature of the thermistor to change by 63.2% of the difference from ambient temperature T 0 to T 1 by the drastic change of the power applied to thermistor from non-zero power to zero-power state. T 1 Temperature X 63.2% T 0 Time
Contents 1 Technical Information Microstructure and Conduction Mechanism NTC Type & working principle Terms and Description 2 Sunlord NTC Thermistor temperature sensor NTC Power NTC 3 Application
Features of Temperature Sensor NTC Large B constant for higher temperature sensing capability Designed for high density Available in a standard EIA compatible case size Improved reliability due to use of internal electrodes Excellent long time aging stability
Temperature Sensor NTC Structure Glass Glass Ni/Sn Ni/Sn External electrode /Ag External electrode/ag NTC Ceramic NTC Ceramic internal electrodes /Ag/Pd single layer structure Composite layer structures
Ordering Information SDNT 1005 X 103 F 3380 F T F 1 2 3 4 5 6 7 8 9 1 Type SDNT Chip NTC Thermistor 4 Zero-power Resistance Example Nominal Value 101 0.1kΩ 103 10kΩ 7 Tolerance of B Constant F ±1% H ±3% 2 External Dimensions (L W) (mm) 1005 [0402] 1.0 0.5 1608 [0603] 1.6 0.8 2012 [0805] 2.0 1.25 5 Tolerance of Resistance F ±1% H ±3% J ±5% K ±10% 8 Packing T Tape & Reel 3 Internal Code X 6 B Constant (25-50 ) Example Nominal Value 3380 3380K 4250 4250K 9 Lead Free Products F
Property Range Table Part No. Resistance at 25 (KΩ) B constant (k) Max. permissive Operating Current (ma) Dissipation Factor (mw/ ) Maximum Rated Power (mw) SDNT1005 0.022~680 3380~4400 0.03~6.7 1.0 100 SDNT1608 0.1~680 3380~4500 0.03~3.1 1.0 100 SDNT2012 0.1~680 3380~4500 0.04~4.0 2.0 200 Tolerance of Resistance :±1%, ±3%, ±5%, ±10% Tolerance of B Constant :±1%, ±3%
R Vs. T Characteristics
Contents 1 Technical Information Microstructure and Conduction Mechanism NTC Type & working principle Terms and Description 2 Sunlord NTC Thermistor temperature sensor NTC Power NTC 3 Application
Structure of Chip Power NTC Glass NTC Ceramic Ni/Sn External electrode/ Ag internal electrodes /Ag/Pd Improved reliability and lower R25 due to use of internal electrodes Developed material (large resistivity and B constant) provide low Residual resistance and high Permissible current SMD type designed for high density Available in a standard EIA compatible case size Excellent long time aging stability
Ordering Information SPNT 451616 X 200 F 4100 H T 1 2 3 4 5 6 7 8 1 Type Chip Power NTC Thermistor 4 Zero-power Resistance Example Nominal Value 200 20Ω 300 30Ω 2 External Dimensions (L W) (mm) 451616[180606] 4.5 1.6 1.6 453216[181206] 4.5 3.2 1.6 453232[181212] 4.5 3.2 3.2 565020[222008] 5.6 5.0 2.0 565040[222016] 5.6 5.0 4.0 806320[312308] 8.0 6.3 2.0 806340[312316] 8.0 6.3 4.0 1008020[393108] 10.0 8.0 2.0 1008040[393116] 10.0 8.0 4.0 3 Internal Code X 5 Tolerance of Resistance K ±10% L ±15% M ±20% 6 Constant (25-50 ) 7 Tolerance of B Constant 8 Packing Example Nominal Value 4100 4100K F ±1% H ±3% T Tape & Reel
Chip Power NTC Property Range Table SUNLORD Chip NTC R25(Ω) B Constant (K) Residual Resistance (Ω) Max. Permissible Current (A) SPNT451616 5-100 4100 0.18-2.6 0.4-2.0 SPNT453216 5-100 4100 0.18-2.6 0.8-2.0 SPNT453232 5-100 4100 0.18-2.6 1.0-3.0 SPNT505620 5-100 4100 0.18-2.6 0.8-3.1 SPNT505640 5-100 4100 0.18-2.6 1.0-4.0 SPNT806320 5-100 4100 0.18-2.6 1.0-4.0 SPNT806340 5-100 4100 0.18-2.6 1.5-5.0 SPNT1008020 5-100 4100 0.18-2.6 1.5-5.0 SPNT1008040 5-100 4100 0.18-2.6 2.0-6.0 Sunlord Chip Power NTC
Excellent Performance of Chip Power NTC The diameter of Pin-type power NTC ranges from 6.5mm to 30mm, while chip NTC can provide at least 50% smaller area to take up less PCB real estate. The height of chip NTC is only 1/4 of that of Pin-type NTC, which will save more space and make machines slimmer. SMD components can lay on both sides of PCB to achieve flexible layout. Sunlord Chip Power NTC
Excellent Performance of Chip Power NTC (cont d) Size Pin-type (diameter ) Φ5 Φ7 Φ9 Φ11 Φ13 Φ15 Φ20 Chip (L W) 4516 4532 4532/5056 5056 5056/8063 8063 10080 B constant(k) Pin-type Chip 2500-3300 4100 2500-3300 4100 2500-3300 4100 2500-3300 4100 2500-3300 4100 2500-3000 4100 2500-3000 4100 Residual Resistance (Ω) Pin-type Chip 0.353-18.7 0.14-7.9 0.283-11.65 0.14-7.9 0.21-30 0.14-13 0.19-3 0.14-1.3 0.17-2.4 0.14-1.3 0.17-2.4 0.14-1.3 0.16-0.9 0.14-0.7 Sunlord The material resistivity of Pin-type is very low (50-200m mω) which results in low B constant and high Residual Resistance. Chip power NTC adopts innovative materials with high resistivity (5000m mω or so) and internal electrode structure, and thus provides high B constant (4000K or more) and low Residual Resistance. Chip Power NTC
Custom-made made Newly Pin-type Power NTC Compatible with custom s original design perfectly due to custom-made NTC; Improved reliability and lower R25 due to use of internal electrodes; Developed material (large resistivity and B constant) provide low Residual resistance and high Permissible current; The height of newly Pin-type power NTC is only 1/2 of that of Pin-type NTC, which make machines slimmer. Chip NTC Tinned round copper wire silicone resin Sunlord Chip Power NTC
Application Notice MAX. Permissible Current:Max. Permissible current of NTC should be larger than circuit operating current. Normally, please choose the NTC with the current 20% or more larger than that. R25: R25 1.414*U/ 1.414*U/Im (U: input AC voltage,im Im: : inrush current); Residual Resistance of Max. Current:The less Resistance of Max. Current is, the less power dissipated in NTC. Please choose the NTC with the least Residual Resistance on condition of fulfilling the above two factors. Permissive Capacitance:At a rated voltage, the capacitance of capacitor connecting with power NTC should not excess the permissive capacitance. Sunlord Chip Power NTC
Contents 1 Technical Information Microstructure and Conduction Mechanism NTC Type & working principle Terms and Description 2 Sunlord NTC Thermistor temperature sensor NTC Power NTC 3 Application
Applications Temperature Sensor NTC Temperature Sensing Temperature Control Temperature Compensation Power NTC Rush Current Suppression
Temperature Sensor NTC-- --Application (1) Digital Thermometer, Electronic Calendar, Clock and other electronic product with temperature display function. Tank level indicating: When connect NTC in a specified circuit, as thermal dissipation constant in different mediums will cause different temperature change, and thus we can indicate the tank level from the changes of resistance. Water Flow Velocity Meter;
Temperature Sensor NTC-- --Application (2) Temperature Control Similar to temperature sensing, the current signal caused by changes of temperature is received by a control circuit so that we can control the electronic equipment. For example, we can use a relay to control on or off of power when the current achieved a certain value to trigger relay.
Temperature Sensor NTC-- --Application (3) for Battery Temperature Monitor FUSE Charge Control IC Li Battery and Ni-MH Battery are widely used in electronic equipments such as Notebook, Mobile phone, and so on. The battery would heat seriously when charging, and it may do wrong work, or even burn out if no measures were taken to control the temperature. Chip NTC thermistor can be applied as temperature sensing to control the battery heat in order to ensure proper charging velocity and fully charge.
Temperature Sensor NTC-- --Application (4) for Amplify Module Voltage Control for Thermostat
Temperature Sensor NTC-- --Application (5) for TCXO, Crystal Oscillator Temperature Compensation Oscillator Crystal, as a frequency generator in communication systems, provides clock signal for data processing equipment and reference signal for system, it is widely used in mobile communication system, aircrafts, PC, and other consumer electronic products. The tolerance of XO depends on temperature, the frequency tolerance is±(10~30) 10-6 at 40 ~+85, while the frequency tolerance of TCXO applied in mobile phone must less than 2.5± 10-6. With a compensation circuit, containing NTC, Capacitance and resistance components, XO can work at a wide temperature range steadily.
Temperature Sensor NTC-- --Application (6) for LCD Brightness & Contrast Compensation The fluid of LCD is sensitive to the temperature, so LCD Module can only work in a limited temperature range. With the temperature increasing, the contrast of LCD gets higher and higher, vise verse. Generally, we have to control LCD module working in a certain temperature range(-20 -+70 ). With NTC compensation, LCD module will be provided higher voltage at low contrast state and lower voltage at higher contrast state so that LCD keeps at a steady contrast state.
Temperature Sensor NTC-- --Application (7) for Disk Drive The disk drives in computers, portable players require high reliability and high-density property. However, the magnetic head output voltage has a negative temperature coefficient characteristics with the temperature coefficient of -0.4% /. With a NTC thermistor compensation, the output voltage will become stable and ensure the disk drive working correctly.
for Coil Temperature Sensor NTC-- --Application (8) Temperature Compensation R1: Coil R2: Resistance RT: NTC Improving the linearity after compensation for Amplify Temperature compensation
Temperature Sensor NTC-- --Application (9) for Transistor Temperature compensation The transistor is sensitive to the temperature, after compensation to Base electrode, the transistor will keep low-distortion characteristics.
Temperature Sensor NTC-- --Application (10) Temperature sensor (high cost) NTC thermistor (low cost)
Temperature Sensor NTC-- --Application (11) Temperature Sensing & Temperature Controlling in Automobile Electronics; Medical Electronic Equipment; Munition Field;
Chip power NTC is one of the most effective and simple measures to solve inrush current problem in AC-DC power supply circuit. Thanks to its small size and low residual resistance, Chip power NTC is especially applicable for the following fields: LED lighting driver, energy-efficient lighting driver LCD-TV Adapter of Notebook, cell phone etc. UPS Power supply of other household appliances Power NTC-- --Application Sunlord Chip Power NTC
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