Chip NTC Thermistor - sunlordinc.com · Shenzhen Sunlord Electronics Co., Ltd ¾Lay the NTC at the temperature sensing place and also make it connect the arm of bridge circuit. As

Shenzhen Sunlord Electronics Co., Ltd

Chip NTC Thermistor


1、Technical InformationMicrostructure and Conduction MechanismNTC Type & working principle Terms and Description

2、Sunlord NTC Thermistortemperature sensor NTCPower NTC

3、Application

ContentsContents


Microstructure and Conduction MechanismMicrostructure 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 CharacteristicsTemperature Characteristics

RT = RN expB(1/T – 1/TN) T： Rated Temperature（ K ）RT：NTC resistance at Temperature T(K). RN：NTC resistance at rated Temperature TN(K). B： NTC B constant


Different types of NTC Different types of NTC ThermistorThermistor

According to different applications，there are two types of NTC thermistors: Temperature sensor NTC & Power NTC

Smaller R25 (several Ω), bigger Permissible Current (several A), bigger thermal time constant & thermal dissipation constant

Rush Current Suppression Power NTC

Larger R25（several KΩ), lower operating current (several mA)，requesting tight tolerance of R25 and B constant

temperature sensing, temperature control, and temperature compensation

Temperature sensor NTC

Electrical featureApplicationType


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 Working Method of Method of Temperature sensor NTC Temperature sensor NTC


Working Working Method of Method of Temperature sensor NTC 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 DescriptionTerms and Description

B-constant:It calculates between two specified ambient temperature by following formula.

T and T0 is absolute temperature(K).

0

0

/1/1)/ln(

TTRRB

−=

R25:R25 refers to the DC resistance measured at a rated temperature (25℃) for an unloaded thermister.

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 DescriptionTerms and DescriptionThermal Dissipation Constant δ : 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. It shows necessary electric power that thermistor’stemperature 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 CapacitanceThe max permissive capacitance may be connected to the thermistor under rated voltage.

0TTW−

=δ


Terms and DescriptionTerms and Description

Thermal Time Constant τ : The total time for the temperature of the thermistor to change by 63.2% of the difference from ambient temperature T0 to T1 by the drastic change of the power applied to thermistor from non-zero power to zero-power state.

Time

T0

T1

X

63.2%Tem

pera

ture

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.




3、Application

ContentsContents


Features of Temperature Sensor NTCFeatures of Temperature Sensor NTC

Large B constant for higher temperature sensing capabilityDesigned for high densityAvailable in a standard EIA compatible case sizeImproved reliability due to use of internal electrodesExcellent long time aging stability


Temperature Sensor NTC StructureTemperature Sensor NTC Structure

single layer structure Composite layer structures

External electrode/Ag

internal electrodes

/Ag/Pd

NTC Ceramic

Ni/Sn

Glass

NTC Ceramic

Ni/Sn

Glass

External electrode

/Ag


Ordering InformationOrdering Information

SDNT 1005 X 103 F 3380 F T F① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨

② External Dimensions(L×W) (mm)

1005 [0402] 1.0×0.51608 [0603] 1.6×0.82012 [0805] 2.0×1.25

① Type

SDNT Chip NTC Thermistor

③ Internal Code

X

④ Zero-power Resistance

Example Nominal Value101 0.1kΩ103 10kΩ

⑧ Packing

T Tape & Reel

⑨ Lead Free Products

F

⑥ B Constant (25-50℃)

Example Nominal Value3380 3380K4250 4250K

⑤ Tolerance of ResistanceF ±1%H ±3%J ±5%K ±10%

⑦ Tolerance of B Constant

F ±1%H ±3%


Property Range TableProperty Range Table

0.04~4.0

0.03~3.1

0.03~6.7

Max. permissive Operating

Current (mA)

2002.03380~45000.1~680SDNT2012

1001.03380~45000.1~680SDNT1608

1001.03380~44000.022~680SDNT1005

Maximum Rated Power (mW)

Dissipation Factor

(mW/℃)

B constant (k)

Resistance at 25℃(KΩ)

Part No.

Tolerance of B Constant ：±1%, ±3%

Tolerance of Resistance ：±1%, ±3%, ±5%, ±10%


R Vs. T Characteristics




3、Application

ContentsContents


External electrode/

Ag

internal electrodes

/Ag/Pd

NTC Ceramic

Ni/Sn

GlassImproved reliability and lower R25 due to use of internal electrodesDeveloped material (large resistivity and B constant) provide low Residual resistance and high Permissible currentSMD type designed for high densityAvailable in a standard EIA compatible case sizeExcellent long time aging stability

Structure of Chip Power NTCStructure of Chip Power NTC


Ordering InformationOrdering Information

SPNT 451616 X 200 F 4100 H T① ② ③ ④ ⑤ ⑥ ⑦ ⑧

② External Dimensions(L×W) (mm)

451616[180606] 4.5×1.6×1.6453216[181206] 4.5×3.2×1.6453232[181212] 4.5×3.2×3.2565020[222008] 5.6×5.0×2.0565040[222016] 5.6×5.0×4.0806320[312308] 8.0×6.3×2.0806340[312316] 8.0×6.3×4.01008020[393108] 10.0×8.0×2.01008040[393116] 10.0×8.0×4.0

① Type

Chip Power NTC Thermistor

③ Internal CodeX

④ Zero-power Resistance

Example Nominal Value200 20Ω300 30Ω

⑦ Tolerance of B Constant

F ±1%H ±3%

⑧ Packing

T Tape & Reel

⑤ Tolerance of Resistance

K ±10%L ±15%M ±20%

⑥ Constant (25-50℃)

Example Nominal Value4100 4100K

Sunlord Chip Power NTCChip Power NTC

Chip Power NTC Property Range TableChip Power NTC Property Range Table

1.0-3.00.18-2.641005-100SPNT453232

2.0-6.00.18-2.641005-100SPNT1008040

1.5-5.00.18-2.641005-100SPNT1008020

1.5-5.00.18-2.641005-100SPNT806340

1.0-4.00.18-2.641005-100SPNT806320

1.0-4.00.18-2.641005-100SPNT505640

0.8-3.10.18-2.641005-100SPNT505620

0.8-2.00.18-2.641005-100SPNT453216

0.4-2.00.18-2.641005-100SPNT451616

Max. Permissible

Current（A）

Residual Resistance

(Ω)

B Constant（K）

R25（Ω）SUNLORD Chip NTC


Excellent Performance of Chip Power NTCExcellent 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.


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.

0.14-0.70.16-0.941002500-300010080Φ20

0.14-1.30.17-2.441002500-30008063Φ15

0.14-1.30.17-2.441002500-33005056/8063Φ13

0.14-1.30.19-341002500-33005056Φ11

0.14-130.21-3041002500-33004532/5056Φ9

0.14-7.90.283-11.6541002500-33004532Φ7

0.14-7.90.353-18.741002500-33004516Φ5

ChipPin-typeChipPin-typeChip(L×W)

Pin-type（diameter

）

Residual Resistance (Ω)B constant（K）Size

Excellent Performance of Chip Power NTC (contExcellent Performance of Chip Power NTC (cont’’d)d)


CustomCustom--made Newly Pinmade Newly Pin--type Power NTCtype 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 resistivityand 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.

Tinned round copper wire

Chip NTC

silicone resin


Application NoticeApplication Notice

MAX. Permissible CurrentMAX. Permissible Current：：Max. Permissible current of Max. Permissible current of NTC should be larger than circuit operating current. NTC should be larger than circuit operating current. Normally, please choose the NTC with the current 20% or Normally, please choose the NTC with the current 20% or more larger than that.more larger than that.

R25: R25: R25R25≥≥1.414*U/1.414*U/ImIm (U: input AC voltage(U: input AC voltage，，ImIm: inrush : inrush current);current);

Residual Resistance of Max. CurrentResidual Resistance of Max. Current：：The less Resistance The less Resistance of Max. Current is, the less power of Max. Current is, the less power dissipated dissipated in NTC. Please in NTC. Please choose the NTC with the least Residual Resistance on choose the NTC with the least Residual Resistance on condition of fulfilling the above two factors.condition of fulfilling the above two factors.

Permissive CapacitancePermissive Capacitance：：At a rated voltage, the At a rated voltage, the capacitance of capacitor connecting with power NTC capacitance of capacitor connecting with power NTC should not excess the permissive capacitance.should not excess the permissive capacitance.




3、Application

ContentsContents


ApplicationsApplications

Temperature Sensor NTCTemperature Sensing

Temperature Control

Temperature Compensation

Power NTCRush Current Suppression


Temperature Sensor NTCTemperature Sensor NTC----Application (1)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 thetank level from the changes of resistance.

Water Flow Velocity Meter;


Temperature ControlSimilar 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.



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.

for Battery Temperature Monitor

FUSE

Charge Control IC



for Amplify ModuleVoltage Control

for Thermostat



for TCXO, Crystal OscillatorTemperature 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.



for LCDBrightness & 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.



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.



R1: CoilR2: ResistanceRT: NTC Improving the linearity

after compensation

for CoilTemperature Compensation

for AmplifyTemperature compensation



The transistor is sensitive to the temperature, after compensation to Base electrode, the transistor will keep low-distortion characteristics.

for TransistorTemperature compensation



Temperature sensor（high cost）

NTC thermistor（low cost）



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 NTCPower NTC----Application Application


THANK YOU!

Documents

Chip NTC Thermistor - sunlordinc.com · Shenzhen Sunlord Electronics Co., Ltd ¾Lay the NTC at the temperature sensing place and also make it connect the arm of bridge circuit. As