# LM35

> integrated circuit - three-terminal temperature sensor

**Wikidata**: [Q5961646](https://www.wikidata.org/wiki/Q5961646)  
**Source**: https://4ort.xyz/entity/lm35

## Summary
The LM35 is a three-terminal integrated circuit used as a precision temperature sensor. It outputs a voltage proportional to the temperature in Celsius, making it widely used in electronic applications for accurate thermal measurement.

## Key Facts
- Instance of: Integrated circuit model, temperature sensor
- Manufacturer: Originally by National Semiconductor; now produced by Texas Instruments
- Primary use: Thermometer applications in electronics
- Subclass of: Integrated circuit, temperature sensor
- Image: [LM35 Temperature Sensor](https://commons.wikimedia.org/wiki/Special:FilePath/LM35_temperature_sensor_semiconductor_thermometer_1480374_5_6_HDR_enhancer.jpg)
- Commons category: LM35
- Available on Wikipedia in languages: Arabic (ar), Commons (commons), Czech (cs), Spanish (es)
- Google Knowledge Graph ID: /g/122hct8v

## FAQs
### Q: What is the LM35 used for?
A: The LM35 is used as a precision temperature sensor in various electronic systems. It provides an analog output voltage linearly proportional to the temperature in degrees Celsius.

### Q: Who manufactures the LM35?
A: The LM35 was originally developed by National Semiconductor and is currently manufactured by Texas Instruments after their acquisition of National Semiconductor in 2011.

### Q: How does the LM35 work?
A: The LM35 generates an output voltage that increases by 10 mV per degree Celsius rise in temperature. This makes calibration straightforward without additional components.

## Why It Matters
The LM35 plays a critical role in embedded systems, industrial control, consumer electronics, and scientific instrumentation where precise temperature monitoring is essential. Its direct proportionality between temperature and output voltage eliminates the need for external calibration or trimming components, simplifying design and reducing cost. As part of the broader family of solid-state sensors, it represents a shift toward more reliable and compact solutions compared to older thermocouple-based methods. Due to its widespread adoption and ease of integration into circuits, the LM35 has become a standard component in prototyping platforms like Arduino and Raspberry Pi projects.

## Notable For
- Linear output of 10 mV per °C with no external calibration required
- Operates over a wide temperature range (-55°C to +150°C)
- Low self-heating and high accuracy characteristics
- Widely supported in educational and maker communities due to simplicity and availability
- Manufactured by Texas Instruments, one of the world's leading semiconductor companies

## Body

### Overview
The LM35 is a monolithic integrated circuit designed specifically for temperature sensing. Unlike many other temperature sensors, it produces an output voltage directly proportional to the Celsius temperature, eliminating the need for offset adjustments or gain stages in most applications.

### Technical Specifications
- Output Scale Factor: 10 mV/°C
- Accuracy: ±0.5°C at room temperature (typical)
- Operating Range: –55°C to +150°C
- Supply Voltage: 4 V to 30 V
- Quiescent Current: Less than 60 µA
- Low Self-Heating: Typically 0.08°C in still air

### Design Features
- Calibrated directly to Celsius
- Linear +10 mV/°C scale factor
- Ensured linearity of ±¼°C over full range
- Rated for full −55° to +150°C range
- Suitable for remote applications using long cables

### Applications
Common uses include:
- Environmental control systems
- Automotive temperature monitoring
- Industrial process controls
- Consumer appliances such as thermostats and HVAC units
- Educational tools in electronics labs and DIY projects

### Manufacturing History
Originally introduced by National Semiconductor, the LM35 became part of Texas Instruments' portfolio following TI’s acquisition of National Semiconductor in September 2011. This transition ensured continued production and support within the global electronics supply chain.

### Availability and Documentation
Texas Instruments continues to provide datasheets, application notes, and development kits for engineers integrating the LM35 into new designs. The device remains readily available through major distributors worldwide.