A temperature reading is the most common measurement in electronics, and it does not always need a smart sensor with a serial interface. The LM35DZ is the classic example of an analog temperature sensor: a three-terminal device whose output voltage is proportional to temperature, ready to read with almost any microcontroller ADC. This guide covers when an analog sensor is the right call, what to verify, and the related parts we stock.
How an analog temperature sensor works
An analog sensor internally produces a voltage that tracks temperature linearly. In the LM35 family the output is scaled at 10 mV per °C, and 0 °C maps to 0 V, so a reading of 250 mV means 25 °C. There is no I²C address, no command set, and no library — connect power, ground and the output to an ADC pin, and you are done. That simplicity is exactly why these parts survive in countless thermostat, appliance and industrial designs.
Analog vs digital: which to choose
- Analog — one wire to an ADC, trivial firmware, low cost, easy to filter. Best for a single temperature in a small or cost-sensitive design.
- Digital (I²C / 1-Wire) — multiple sensors on one bus, higher resolution, often factory-calibrated. Best when you need several points or want to avoid analogue front-end work.
For most boards that already have an ADC channel free, the analog part is the faster path to a working measurement.
What to verify before you substitute
- Supply range — make sure the sensor accepts your rail; analog temperature sensors are not all 5 V tolerant.
- Accuracy grade — accuracy is usually quoted at 25 °C and can widen across the full range; pick the grade your application needs.
- Package and pinout — the TO-92 and small-surface-mount versions differ in footprint and thermal coupling to the board.
- Self-heating — keep load on the output pin small so the sensor measures the environment, not itself.
Temperature and environmental sensors we stock
| Part | Type | Typical use | Link |
|---|---|---|---|
| LM35DZ | Analog temperature sensor, TO-92 | Thermostats, appliances, general monitoring | LM35DZ |
| SHT31-DIS-B | Digital humidity & temperature sensor | HVAC, environmental logging | SHT31-DIS-B |
| AHT20 | Digital temperature & humidity | Consumer and IoT devices | AHT20 |
| BME680 | Temp / humidity / pressure / gas | Weather and air-quality nodes | BME680 |
See the full sensor range. Prices move with quantity and market, so send your part number, package and quantity for a real-time quote.
Frequently asked questions
What does an analog temperature sensor actually output?
A part like the LM35 outputs a voltage that is directly proportional to temperature, typically 10 mV per degree Celsius, with theCelsius zero point mapped to 0 V. You read it with any ADC and divide by the scale factor; there is no serial protocol and no conversion firmware to write.
When is an analog sensor better than a digital one?
Analog sensors win on simplicity and cost when you only need a single temperature and already have an ADC channel free. They also avoid the addressing and protocol overhead of digital buses, which matters in small MCU designs and in electrically noisy environments where a slow analogue line can be easier to filter than a fast digital one.
What should I check before substituting an LM35-class part?
Confirm the supply voltage range, the accuracy grade at the temperature you care about, the package, and whether you need the calibrated Celsius output or a part scaled in another unit. Always verify the exact electrical ratings against the manufacturer's datasheet before design-in.
Do you stock LM35 and similar sensors?
Yes. We stock the LM35DZ along with other temperature and environmental sensors, and we can quote by quantity with date codes so you can validate before committing to volume.
Recommended next steps
If you are sourcing any of the parts mentioned in this guide, we can help you confirm stock, pricing, and lead times quickly.
- Upload your BOM — send your full parts list and receive a consolidated quote within 2 business hours.
- Browse related in-stock lines: Sensors / Optoelectronic.
- Contact our team for hard-to-find or end-of-life components.
About us & trademarks: JTDZ Tech (Shenzhen Jingteng Electronics Technology Co., Ltd.) is an independent distributor of electronic components. We are not an authorised distributor or representative of the manufacturers named in this article. Manufacturer and part names are used for indicative purposes only, to help identify the components discussed; all trademarks remain the property of their respective owners. Always verify specifications against the manufacturer's datasheet before design-in or purchase.
