What is LM35?
These are commonly used, highly accurate integrated temperature measurement sensor, whose electrical output voltage is proportional to its measured temperature in degree Celsius.
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LM35 typically operates at voltage levels between 4 and 30 volts.
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Has an output voltage range from -50 deg C to 150 deg C.
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Has a linear rise of 10mv/deg C (scale factor).
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Has a drain current of less than 60mA.
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It is a low-cost temperature sensor.
Characteristic
The LM35 series are precision integrated-circuit temperature devices with an output voltage linearly proportional to the Centigrade temperature.
LM35 is a three-terminal linear temperature sensor from National semiconductors. It can measure temperature from -55 degree Celsius to +150 degree Celsius. The voltage output of the LM35 increases 10mV per degree Celsius rise in temperature.
LM35 can be operated from a 5V supply and the stand by current is less than 60uA. The pinout of LM35 is shown in the figure below.
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• Calibrated Directly in Celsius (Centigrade)
• Linear + 10-mV/°C Scale Factor
• 0.5°C Ensured Accuracy (at 25°C)
• Rated for Full −55°C to 150°C Range
• Suitable for Remote Applications
• Low-Cost Due to Wafer-Level Trimming
• Operates from 4 V to 30 V
• Less than 60-μA Current Drain
• Low Self-Heating, 0.08°C in Still Air
• Non-Linearity Only ±¼°C Typical
• Low-Impedance Output, 0.1 Ω for 1-mA Load
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Introduction
Features
LM35 vs Thermistors
One big advantage LM35 has over-temperature sensors measured in Kelvins is that a large constant voltage does not need to be subtracted from the output to obtain an accurate temperature reading.
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LM35 also does not need extra calibration or external trimming to provide accurate results, compared to other temperature sensors.
