LM35 Precision Temperature Sensor – ±0.5°C Accuracy 10 mV/°C Output

LM35 Precision Temperature Sensor

(±0.5 °C Accuracy, 10 mV/°C Output)

The LM35 is a high-precision analog temperature sensor designed to provide accurate and linear temperature measurements. It outputs a voltage that is directly proportional to temperature in degrees Celsius, eliminating the need for complex calibration or conversion formulas.

Key Features

• High accuracy: ±0.5 °C at room temperature

• Linear output: 10 mV per °C

• Calibrated directly in Celsius

• Low self-heating (<0.1 °C in still air)

• Low power consumption

• Wide operating voltage range

Working Principle

The LM35 operates based on the temperature-dependent characteristics of semiconductor junctions. As temperature increases, the internal circuitry generates a proportional voltage change at the output pin. For every 1 °C rise in temperature, the output voltage increases by 10 mV.

Example:

• 25 °C → 250 mV

• 30 °C → 300 mV

• 100 °C → 1.00 V

Pin Configuration (TO-92 Package)

1. VCC – Supply voltage (4 V–30 V)

2. VOUT – Analog temperature output

3. GND – Ground

Electrical Specifications

• Accuracy: ±0.5 °C (at 25 °C)

• Measurement Range: −55 °C to +150 °C

• Sensitivity: 10 mV/°C

• Supply Voltage: 4 V to 30 V

• Current Drain: ~60 µA

• Output Type: Analog

Advantages

• No need for external calibration

• Easy interfacing with Arduino, Raspberry Pi, ESP32, and PIC

• Stable and reliable temperature readings

• Cost-effective and widely available

• Ideal for embedded and IoT systems

Applications

• Weather monitoring systems

• IoT temperature monitoring

• Home automation

• Medical equipment

• Industrial temperature control

• Robotics and automation projects

• Educational and laboratory experiments

Conclusion

The LM35 Precision Temperature Sensor is a reliable, accurate, and easy-to-use temperature sensing solution. With its linear 10 mV/°C output, low power consumption, and high accuracy, it is an excellent choice for embedded systems, IoT applications, and academic projects where precise temperature measurement is required.