When selecting a temperature sensor for an application, it may be tempting to opt for an economical option that meets the basic requirements of the electronic product under development. However, it is worth considering that investing in a high-quality sensor could be a game-changer for the final product’s quality.
While some standard digital sensors offer acceptable accuracy for the device’s functionality, their accuracy may be limited to specific temperature ranges and consume more power compared to other options available in the market. Consequently, the lifespan and quality of the product could be significantly affected.
There are many types of temperature sensors and selecting the appropriate one primarily depends on the application. On the one hand, Thermistors are widely used in medical and industrial applications, among others; however, they might have some drawbacks that need to be considered when using them. First, they are susceptible to self-heating errors, which can lead to inaccurate temperature measurements if not properly accounted for. Second, their resistance change with temperature might be significantly non-linear, which can make it difficult to accurately interpret temperature measurements across a wide temperature range. Finally, NTC thermistors require shielding of power lines to prevent interference and noise that can affect the accuracy of temperature measurements.
Like NTC Thermistors, digital temperature sensors are also attractive for diverse applications in industry and medicine. These sensors offer several advantages, including accuracy, stability, and ease of use, as standard communication protocols can be utilized. Unlike NTC Thermistors, some digital temperature sensors provide a pulse count output that offers high-precision temperature measurements. The pulse count method outputs a series of digital pulses that represent the temperature reading directly, rather than requiring the conversion of an analog signal to a digital value. This approach can reduce the amount of noise and errors in the measurement process and approximates the output transfer function to be linear.
One example of a digital temperature sensor with pulse count output is the NST1001 by Novosense. This sensor has two pins and a unique pulse-counting digital output, which allows for direct connection to the GPIO of the MCU and maximum resource savings.
The NST1001 offers high accuracy and resolution over a temperature range of -50°C to 150°C. It outputs a minimum of 1 pulse and a theoretical maximum of 3201 pulses, with each pulse having a weight of 0.0625°C. As such, one pulse corresponds to a temperature less than -50°C, while a pulse count of 3201 corresponds to a temperature greater than 150°C.
Another advantage that this sensor offers is a fast temperature response (t < 0.25s @ Stilling Oil, DFN-2L) and conversion cycle time (50 ms). This makes it a suitable choice for applications that require a dynamic response to temperature changes.
Additionally, the NST1001 proves to be an excellent option for low-power applications, particularly for battery-operated devices, wearables, cold chain monitoring, and environmental monitoring, among others.
This is because of its ultra-low power consumption. Medium power consumption is only around 15µA typical (30 µA during conversion (24ms), 1µA during communication (26ms)) and zero power consumption in standby mode.
As a result the sensor can operate in battery driven applications for extended periods. The low power consumptions also makes it obsolete to consider self-heating errors
The NST1001 is available in TO-92S-2L and DFN-2L packages, both have one DQ pin for digital I/O and GND.
Whether you are looking for temperature sensors or other sensor technology. Talk to us – we are sure to find a suitable solution for you: