LM35 TO-92-3 Board Mount Temperature Sensors

The electrical output of the integrated analogue temperature sensor LM35 is proportional to degrees Celsius. For the LM35 Sensor to achieve normal accuracy, no external calibration or trimming is needed. The LM35’s ability to interface with readout or control circuitry is facilitated by its low output impedance, linear output, and perfect intrinsic calibration.

Because of this, no additional parts are needed to interface the LM35 to the ADC because its output is linear with a 10 mv/degree scale. Any 10 or 12 bit ADC can be directly interfaced with it. However, if you need to measure a 1°C change, you will need an amplifier section if you are using an 8-bit ADC like the ADC0808 or ADC0804.

LM35 and Arduino can also be linked directly. The temperature output of the LM35 can also be connected to a comparator circuit for over-temperature indication, or it can be utilised as a temperature controller by using a straightforward relay.

The operating temperature range of the LM35 device is −55°C to 150°C, whereas the LM35C device has a rating of −40°C to 110°C (−10° with enhanced accuracy). While the LM35C, LM35CA, and LM35D devices are available in the plastic TO-92 transistor packaging, the LM35-series devices are packaged in hermetic TO transistor packages. The LM35D device comes in a plastic TO-220 package and an 8-lead surface-mount small-outline package.

Qualities:

• Directly calibrated in degrees Celsius (Centigrade) with a linear scale factor of 10.0 mV/°C
• Guaranteed accuracy of 0.5°C (at 25°C)
• Fit for applications that require remote access
• Due to wafer-level cutting, costs are low.
• Runs on 4 to 30 volts.
• 60 mA or less of current drain
• Low self-heating; in steady air, 0.08°C
• Typical nonlinearity is only 0.25°C.
• Output with low impedance, 0.1Ω for a 1 mA load