LM235

LM135-LM235-LM335 Precision temperature sensors Features ■ ■ ■ ■ Directly calibrated in °K 1°C initial accuracy Operates from 450µA to 5mA Less than 1Ω dynamic impedance TO-92 (Plastic package) Description The LM135, LM235, LM335 are precision temperature sensors which can be easily calibrated. They operate as a 2-terminal Zener and the breakdown voltage is directly proportional to the absolute temperature at 10mV/°K. The circuit has a dynamic impedance of less than 1Ω and operates within a range of current from 450µA to 5mA without alteration of its characteristics. Calibrated at +25°C, the LM135, LM235, and LM335 have a typical error of less than 1°C over a 100°C temperature range. Unlike other sensors, the LM135, LM235, LM335 have a linear output. SO-8 (Plastic micropackage) Pin connections TO-92 (Bottom view) v- ADJ v+ SO-8 (Top view) V+ 8 NC 7 NC 6 ADJ 5 NC 1 2 NC NC 3 4 V- February 2008 Rev 3 1/16 www.st.com 16 Schematic diagram LM135-LM235-LM335 1 Schematic diagram Figure 1. Schematic diagram 2 Absolute maximum ratings Table 1. Symbol Current Reverse Forward Operating free-air temperature range(1) Continuous Intermittent Storage temperature range Absolute maximum ratings (AMR) Parameter LM135 LM235 LM335LM335A Unit IR IF 15 10 mA Toper -55 to +150 -40 to +125 -40 to +100 +150 to +200 +125 to +150 +100 to +125 -65 to +150 °C Tstg °C 1. Tj ≤ 150°C 2/16 LM135-LM235-LM335 Temperature accuracy 3 Table 2. Temperature accuracy Temperature accuracy Parameter LM135 - LM235 LM335A Min. Typ. Max. Min. LM335 Unit Typ. Max. Operating output voltage Tcase = +25°C, IR = 1mA Uncalibrated temperature error (IR = 1mA) Tcase = +25°C Tmin ≤ Tcase ≤ Tmax Temperature error with 25°C calibration Tmin ≤ Tcase ≤ Tmax., IR = 1mA LM135 - LM235 LM335 LM335A Calibrated error at extended temperature Tcase = Tmax (intermittent) Non-linearity (IR = 1mA) LM135 - LM235 LM335 LM335A 2.95 2.98 1 2 3.01 3 5 2.92 2.98 4 5 3.04 6 9 V °C 0.5 0.5 2 0.3 0.3 1.5 1 1 2 1 0.3 1.5 1.5 2 °C °C °C 4 Table 3. Electrical characteristics Electrical characteristics LM135 - LM235 Parameter Min. Typ. 2.5 0.5 +10 80 10 1 0.2 Max. 10 Min. Typ. 3 0.6 +10 80 10 1 0.2 Max. 14 mV Ω mV/°C LM335-LM335A Unit Operating output voltage change with current 450µA ≤ IR ≤ 5mA at constant temperature Dynamic impedance (IR = 1mA) Output voltage temperature drift Time constant Still air Air 0.5m/s Stirred oil Time stability (Tcase = +125°C) s °C/kh Note: Accuracy measurements are made in a well-stirred oil bath. For other conditions, selfheating must be considered 3/16 Electrical characteristics LM135-LM235-LM335 Figure 2. Reverse voltage change (mV) Reverse voltage change Figure 3. Calibrated error Calibrated error (°C) Reverse current (mA) Figure 4. Reverse characteristics Figure 5. Temperature (°C) Response time Reverse current (mA) Reverse voltage (V) Figure 6. Dynamic impedance (Ohm) Dynamic impedance Figure 7. Voltage swing (V) Time (µs) Noise voltage Noise (nV/√ Hz) Frequency (Hz) Frequency (Hz) 4/16 LM135-LM235-LM335 Electrical characteristics Figure 8. Thermal resistance (°C/W) Thermal resistance junction to air Figure 9. Thermal time constant Time constant (s) Air velocity (m/s) Figure 10. Thermal response in still air Air velocity (m/s) Figure 11. Thermal response in stirred oil bath Percent of final value (%) Time (min) Figure 12. Forward characteristics Percent of final value (%) Time (s) Forward voltage (V) Forward current (mA) 5/16 Application information LM135-LM235-LM335 5 Application information There is an easy method of calibrating the device for higher accuracies (see Typical applications). The single point calibration works because the output of the LM135, LM235, LM335 is proportional to the absolute temperature with the extrapolated output of sensor going to 0V at 0°K (-273.15°C). Errors in output voltage versus temperature are only slope. Thus a calibration of the slope at one temperature corrects errors at all temperatures. The circuit output (calibrated or not) is given by the equation: T VOT + VOTO x -----To where T is the unknown temperature and To is the reference temperature (in °K). Nominally, the output is calibrated at 10mV/°K. Precautions should be taken to ensure good sensing accuracy. As in the case of all temperatures sensors, self-heating can decrease accuracy. The LM135, LM235, and LM335 should operate with a low current but sufficient to drive the sensor and its calibration circuit to their maximum operating temperature. If the sensor is used in surroundings where the thermal resistance is constant, the errors due to self-heating can be externally calibrated. This is possible if the circuit is biased with a temperature stable current. Heating will then be proportional to Zener voltage and therefore temperature. In this way, the error due to self-heating is proportional to the absolute temperature as scale factor errors. Typical applications Figure 13. Basic temperature sensor Figure 14. Wide operating supply 6/16 LM135-LM235-LM335 Application information Figure 15. Calibrated sensor Figure 16. Average temperature sensing * Calibrated for 2.982V at 25°C Figure 17. Isolated temperature sensor 7/16 Application information Figure 18. Simple temperature controller LM135-LM235-LM335 Figure 19. Centigrade thermometer 8/16 LM135-LM235-LM335 Figure 20. Differential temperature sensor Application information Figure 21. Thermocouple cold junction compensation (compensation for grounded thermocouple) 9/16 Application information Figure 22. Single power supply cold junction compensation LM135-LM235-LM335 10/16 LM135-LM235-LM335 Package information 6 Package information In order to meet environmental requirements, STMicroelectronics offers these devices in ECOPACK® packages. These packages have a lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an STMicroelectronics trademark. ECOPACK specifications are available at: www.st.com. 6.1 TO-92 tape & reel package information Figure 23. TO-92 tape & reel package mechanical drawing A1 P P T H d A H1 H0 H I1 W0 D0 F1 F2 P2 P0 W2 W1 W L1 11/16 Package information Table 4. Dim. Min. AL A T d I1 P PO P2 F1/F2 Δh ΔP W W0 W1 W2 H H0 H1 DO L1 3.8 4.0 15.5 16 2.5 11.7 12.4 5.95 2.4 -1 -1 17.5 5.7 8.5 12.7 12.7 6.35 2.5 0 0 18.0 6 9 13.7 13 6.75 2.8 1 1 19.0 6.3 9.75 0.5 20 16.5 25 4.2 11 0.150 0.610 0.45 0.098 0.461 0.488 0.234 0.094 -0.039 -0.039 0.689 0.224 0.335 Typ. Max. 5.0 5.0 4.0 Min. LM135-LM235-LM335 TO-92 tape & reel package mechanical data Millimeters Inches Typ. Max. 0.197 0.197 0.157 0.018 0.500 0.500 0.250 0.098 0 0 0.709 0.236 0.354 0.539 0.512 0.266 0.110 0.039 0.039 0.748 0.248 0.384 0.020 0.787 0.630 0.650 0.984 0.157 0.165 0.433 12/16 LM135-LM235-LM335 Package information 6.2 TO-92 bulk package information Figure 24. TO-92 bulk package mechanical drawing Table 5. Dim. TO-92 bulk package mechanical data Millimeters Min. Typ. 1.27 3.2 4.45 4.58 12.7 0.407 0.35 0.5 0.508 3.7 5.00 5.03 4.2 5.2 5.33 0.126 0.1752 0.1803 0.5 0.016 0.0138 0.0197 0.02 Max. Min. Inches Typ. 0.05 0.1457 0.1969 0.198 0.1654 0.2047 0.2098 Max. L B O1 C K O2 a 13/16 Package information LM135-LM235-LM335 6.3 SO-8 package information Figure 25. SO-8 package mechanical drawing Table 6. SO-8 package mechanical data Dimensions Ref. Min. A A1 A2 b c D H E1 e h L k ccc 0.25 0.40 1° 0.10 1.25 0.28 0.17 4.80 5.80 3.80 Millimeters Typ. Max. 1.75 0.25 0.004 0.049 0.48 0.23 4.90 6.00 3.90 1.27 0.50 1.27 8° 0.10 0.010 0.016 1° 5.00 6.20 4.00 0.011 0.007 0.189 0.228 0.150 Min. Inches Typ. Max. 0.069 0.010 0.019 0.010 0.193 0.236 0.154 0.050 0.020 0.050 8° 0.004 0.197 0.244 0.157 14/16 LM135-LM235-LM335 Ordering information 7 Ordering information Table 7. Order codes Temperature range -55°C to +150°C -40°C to +125°C -40°C to +125°C Package TO-92 SO-8 TO-92 Packing Bulk Tube or Tape & reel Bulk Marking LM135 LM235 LM235 LM335 -40°C to +100°C LM335AD LM335ADT LM335Z LM335AZ LM335AZT -40°C to +100°C TO-92 SO-8 Tube or Tape & reel LM335A Bulk Bulk or Tape & reel LM335 LM335A Order code LM135Z LM235D LM235DT LM235Z LM335D LM335DT 8 Revision history Table 8. Date 6-May-2003 13-April-2004 Document revision history Revision 1 2 Initial release. Corrected error in pinout diagram for TO-92 package on cover page (it is a bottom view, not a top view). Updated Section 6: Package information and Table 7: Order codes. Corrected typical values for uncalibrated temperature error in Table 2. Improved quality of electrical characteristics curves. Changes 11-Feb-2007 3 15/16 LM135-LM235-LM335 Please Read Carefully: Information in this document is provided solely in connection with ST products. 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