DatasheetsPDF.com

LM335A Dataheets PDF



Part Number LM335A
Manufacturers STMicroelectronics
Logo STMicroelectronics
Description Precision temperature sensor
Datasheet LM335A DatasheetLM335A Datasheet (PDF)

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 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.

  LM335A   LM335A


Document
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 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. TO-92 (Plastic package) SO-8 (Plastic micropackage) Pin connections TO-92 (Bottom view) ADJ v+ v- SO-8 (Top view) V+ NC NC ADJ 8 7 6 5 1 2 3 NC NC NC 4 V - February 2008 Rev 3 1/16 www.st.com 16 Schematic diagram 1 Schematic diagram Figure 1. Schematic diagram LM135-LM235-LM335 2 Absolute maximum ratings Table 1. Absolute maximum ratings (AMR) Symbol Parameter LM135 LM235 LM335LM335A Unit Current IR IF Reverse Forward Toper Operating free-air temperature range(1) Continuous Intermittent Tstg Storage temperature range 1. Tj ≤ 150°C 15 mA 10 °C -55 to +150 -40 to +125 -40 to +100 +150 to +200 +125 to +150 +100 to +125 -65 to +150 °C 2/16 LM135-LM235-LM335 3 Temperature accuracy Temperature accuracy Table 2. Temperature accuracy Parameter 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 LM135 - LM235 LM335A LM335 Unit Min. Typ. Max. Min. Typ. Max. 2.95 2.98 3.01 2.92 2.98 3.04 V 1 3 2 5 4 6 °C 5 9 0.5 1.5 0.5 1 2 0.3 1 0.3 1.5 °C 1 2 2 °C °C 0.3 1.5 4 Electrical characteristics Table 3. Electrical characteristics Parameter LM135 - LM235 LM335-LM335A Unit Min. Typ. Max. Min. Typ. Max. 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) 2.5 10 0.5 +10 80 10 1 0.2 3 14 mV 0.6 Ω +10 mV/°C 80 s 10 1 0.2 °C/kh Note: Accuracy measurements are made in a well-stirred oil bath. For other conditions, selfheating must be considered 3/16 Electrical characteristics Figure 2. Reverse voltage change LM135-LM235-LM335 Figure 3. Calibrated error Calibrated error (°C) Reverse voltage change (mV) Reverse current (mA) Figure 4. Reverse characteristics Temperature (°C) Figure 5. Response time Voltage swing (V) Reverse current (mA) Reverse voltage (V) Figure 6. Dynamic impedance Time (µs) Figure 7. Noise voltage Noise (nV/√Hz) Dynamic impedance (Ohm) Frequency (Hz) 4/16 Frequency (Hz) LM135-LM235-LM335 Electrical characteristics Figure 8. Thermal resistance junction to air Figure 9. Thermal time constant Time constant (s) Thermal resistance (°C/W) 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 (%) Percent of final value (%) Time (min) Figure 12. Forward characteristics Time (s) Forward voltage (V) Forward current (mA) 5/16 Application information 5 Application information LM135-LM235-LM335 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: VOT + VOTO x --T---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 du.


LM335 LM335A ELJRExxxxF


@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site.
(Privacy Policy & Contact)