Body Temperature Sensor Basics: Specifications and Manufacturers

This article covers the fundamentals of body temperature sensors, their features, specifications, and some key digital temperature sensor manufacturers. Companies like MAXIM, TE Connectivity, Analog Devices, STMicroelectronics, and Texas Instruments (TI) are prominent players in this space.

Introduction

Human body temperature is not a constant value; it varies depending on the measurement location, the time of day, and the person’s activity level.

Typically, the average body temperature falls within the range of 97.7 to 99.5°F (36.5 to 37.5°C), fluctuating by about 0.9°F (0.5°C) throughout the day. Monitoring body temperature is essential, as it can be an indicator of certain illnesses and can help evaluate the effectiveness of medical treatments.

The following table outlines different body temperature ranges and associated conditions:

What is a Body Temperature Sensor?

Definition: A body temperature sensor is a device designed to measure the temperature of a human body. These sensors find application in wearable fitness trackers and medical thermometers.

Technical Specifications: MAX30205 (Maxim Integrated)

The MAX30205, manufactured by Maxim Integrated, is a good example of a body temperature sensor. Here’s a look at its key specifications:

• High Accuracy: Designed for precise temperature readings.
• Overtemperature Alarm: Features an interrupt and shutdown output for detecting high temperatures.
• I2C Interface: Uses a 2-wire I2C-compatible interface for communication.
• Sigma-Delta ADC: Converts temperature to a digital format using a sigma-delta Analog-to-Digital Converter (ADC).
• Address Selection: Provides three address select lines, allowing for 32 unique addresses.
• High Resolution: Offers 16-bit temperature resolution.
• Low Power Consumption: Operates on 2.7V to 3.3V with a supply current of approximately 600 µA.

IC-Based Digital Temperature Sensor Manufacturers

Here’s a list of companies that manufacture digital temperature sensors:

• Analog Devices, Inc.
• Texas Instruments Incorporated
• STMicroelectronics
• Maxim Integrated
• TE Connectivity

Image Courtesy: Maxim Integrated

The image above illustrates how a body temperature sensor can be interfaced with an STM32 microcontroller. The I2C interface on the MAXIM IC facilitates easy integration with microcontrollers like the STM32 or Arduino Uno. The MAX30205 can be seamlessly incorporated into the design of smart health bands and various medical devices.

The TSYS01-1, a digital IC temperature sensor from TE Connectivity, boasts the following features:

• High Accuracy: Offers accuracy of approximately +/-0.1°C.
• Connectivity: Supports both I2C and SPI interfaces for flexible connectivity options.
• Digital Conversion: Converts temperature into a digital 16/24-bit ADC value.