Choosing the right probe temperature sensor is about more than just accuracy and range. The type of output signal is also important. It affects your whole system design.

As a maker of many types of sensors, we understand the importance of knowing the signal type. We offer classic NTC thermistors, RTDs (PT100/PT1000), and modern sensors like DS18B20 and TMP117. Understanding the signal type is the first step to success.

Analog vs Digital Temperature Sensors: What’s the Difference?

The Analog Approach: The Raw Signal

Analog sensors are the "classic" solution. They provide a continuous signal — typically a change in resistance or voltage — that is proportional to the temperature.

• Resistive Sensors: This group includes our NTC thermistors and RTDs (PT100/PT1000). As temperature changes, their electrical resistance changes in a predictable way.
• Voltage Sensors: Devices like thermocouples and the LM35 sensor fall here. They output a small, continuous voltage (e.g., 10mV per °C for the LM35) that corresponds to the temperature.

This raw signal is vulnerable to electrical noise and requires external circuitry. Your microcontroller cannot directly measure resistance. You need to create a conditioning circuit, like a voltage divider or amplifier. Then, use an Analog-to-Digital Converter (ADC) to change the signal into a value your system can understand.

Best for: Cost-sensitive designs, high-resolution analog systems, and applications where you fully control the signal conditioning.

The Digital Approach: The Smart Sensor

Digital sensors are "smart" devices. They are integrated circuits (ICs). These ICs have an analog sensor, signal conditioning, an ADC, and digital communication logic all in one small package.

DS18B20 (using the 1-Wire protocol) and TMP117 (using I²C) are prime examples.

When you "talk" to these sensors using their digital protocol, they don't send you a raw, noisy voltage. They send you a fully processed, calibrated, and precise temperature reading in binary.

The benefits are huge:

• Noise Immunity: The digital signal is highly resistant to electrical noise, even over long wires.
• Ease of Use:No intricate wiring or adjustments required.. Just connect it to the digital pins of your microcontroller..
• Scalability: You can often put multiple digital sensors on the same communication bus.

Best for: Applications requiring high accuracy with minimal design effort, noisy electrical environments, and systems using microcontrollers.

Which Sensor Output Is Right for You?

The choice is simple:

Do you need a basic, flexible part for a custom analog design (NTC/RTD)? Or do you want a smart, noise-resistant sensor that provides a direct temperature reading (DS18B20/TMP117)?

Whatever your application, we Focusens manufacture high-quality sensors you need to get the job done.

Email us and we will elaborate and matching the sensor that well suit your applications.