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.
-
LM35 typically operates at voltage levels between 4 and 30 volts.
-
Has an output voltage range from -50 deg C to 150 deg C.
-
Has a linear rise of 10mv/deg C (scale factor).
-
Has a drain current of less than 60mA.
-
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.
• 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
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.
LM35 also does not need extra calibration or external trimming to provide accurate results, compared to other temperature sensors.
