6000 5000 4000 3000 2000 B=1000 NTC Thermistors The NTC Thermistors NTC Thermistors is a negative temperature coefficient resistor that significantly reduces its resistance value as the heat/ ambient temperature rises. Thermistors is sintered in high-temperature (1200 C to 1500 C), and manufactured in various shapes. Its comprised of 2 to 4 kinds of metal oxides: iron, nickel, cobalt, manganese and copper. Features Recommended Applications Temperature Coef cient of Resistance is negative, For temperature measurement or temperature and its extremely large (2.8 to 5.1 %/C ). detection : Thermometer, temperature controller Various shapes, especially compact size For temperature compensation : Transistor, transistor components are available. circuit, quarts oscillation circuit, and measuring instruments Selection of resistance vale is comparatively free, its available from several tens to several hundred k. Physical Characteristics of NTC Thermistors Thermistor is a resistor sensitive to temperature that is Fig. 1 utilizing the characteristic of metal oxide semiconductor 1000 having large temperature coef cient. And its temperature dependency of resistance value is indicated by the following equation : 100 1 1 ..................................... 0 R=R exp B (1) ( ) 10 T 0 T T0 : Standard Temperature 298.15 K(25 C) R : Resistance at T K 0 0 1 B : Thermistor Constant K Temperature coef cient (a) in general meaning is indicated 0.1 as follows : B .................................................................... 0.01 a= (2) 2 T Since the change by temperature is considerably large, a is 0.001 not appropriate as a constant. Therefore, B value (constant) 40 20 0 20 40 60 80 100 120 140 is generally used as a coef cient of thermistors. T (C) Major Characteristics of NTC Thermistors The relation between resistance and temperature of a thermistor is linear as shown in Fig. 2. The resistance Fig. 2 value is shown in vertical direction in a logarithmic scale 10000000 and reciprocal of absolute temperature (adding 273.15 to centigrade) is shown in horizontal direction. The B value (constant) determines the gradient of these 1000000 straight lines. The B value (constant) is calculated by using following equation. 100000 1 2 knR knR 10000 ....................................................... B = (3) 1 1 T1 T2 1000 R : Resistance at T K 1 1 R : Resistance at T K 2 2 100 When you calculate this equation, youll nd that B value is not exactly constant. The resistance is expressed by 10 the following equation : C ............................................................. R = AT exp D/T (4) 1 2.4 2.9 3.4 3.9 4.4 In (4), C is a small positive or negative constant and quite 1 3 1 (10 K ) negligible except for use in precision temperature-measuring T device, therefore, the B value can be considered as constant 125 85 50 25 0 20 40 number. T (C) In Fig. 1, the relation between the resistance ratio R /R (R : Resistance at 25 C, RT : Resistance at T C) T 25 25 and B Value is shown with T C, in the horizontal direction. Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 02 May. 2015 EE 0000 AA11 88 00 ==22 55//55 BB 22 0011 00 TT JJ EE RR 3344 55//88 3355 AA == 55 33 TT BB 22 1100 EE GG JJ00 EERR 05500 55//5500 BB 22 =40 = 4 7733 PP44 TTJJ EE 00 55 00 4422 2255// RR EE == 5500 BB 00 00 11 33 EERR 4477 RR TT JJ EE 00 00 0000 == 00 55/5/5 BB 22 == 5050 4455 2255// BB VV JJ00 TT 1100 EE RR 22 00 44 TT11 RR EE 00EE EE TTJJ R () RT/R25Multilayer NTC Thermistors Multilayer NTC Thermistors Series: ERTJ Features Surface Mount Device (0201, 0402, 0603) Highly reliable multilayer / monolithic structure Wide temperature operating range (40 to 125 C) Environmentally-friendly lead-free RoHS compliant Recommended Applications Mobile Phone Temperature compensation for crystal oscillator Temperature compensation for semiconductor devices Personal Computer and Peripheral Device Temperature detection for CPU and memory device Temperature compensation for ink-viscosity (Inkjet Printer) Battery Pack (secondary battery) Temperature detection of battery cells Liquid Crystal Display Temperature compensation of display contrast Temperature compensation of display backlighting (CCFL) Explanation of Part Numbers 1 2 3 4 5 6 78 9 10 11 12 (Example) E R T J 0 E G 103J A Packaging B Value Class Code Nominal Resistance Resistance Tolerance Common Code Size Code Style Code R () Code Product Code Type Code Z 0201 A 2701 to 2800 25 ERT NTC J Chip Type (SMD) 0 0402 G 3301 to 3400 The rst two digits F 1% E 0201, 0402 Narrow Pressed Carrier are signicant gures Thermistors Multilayer Type 1 0603 M 3801 to 3900 Tolerance G 2% Taping of resistance and the Type P 4001 to 4100 Punched Carrier third one denotes R 4201 to 4300 H 3% Standard Taping the number of zeros Type S 4301 to 4400 J 5% (Pitch : 2 mm) following them. T 4401 to 4500 V 0603 Special V 4601 to 4700 Punched Carrier Specication Taping (Pitch : 4 mm) Construction No. Name Semiconductive Ceramics A 3 4 Internal electrode B 5 Substrate electrode C Terminal 2 Intermediate electrode 1 D electrode External electrode E Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 03 May. 2015