Integration and Performance
The IoT phenomenon continues to rev into high gear and sensor innovations have had to keep pace. That’s driven manufacturers of sensors ICs to develop highly integrated, high-performance devices.
Sensors play a key role in embedded systems because they are the devices that interact directly with the real world. With the Internet-of-Things (IoT) phenomenon charging ahead, sensor IC manufacturers solutions have been hard at work developing new products. This means either adding more capability or combining multiple sensor functions on a single device. Either way, the trend in sensor technology is toward integration.
Sensors span a wide variety of sensor types and functions including: temperature, pressure, motion, gas detection, imaging and more. Weave in the proliferation of IoT and intelligent edge applications, sensors are also moving to smaller, low-power designs to meet the new requirements of those systems. Because there are so many different types of sensors, the sensors in this article’s product gallery are just a representative slice of today’s offerings among new products introduced over the past 12 months. Aside from sensor specialist companies, it’s clear that microcontroller (MCU) and analog IC vendors have led many of the sensor technology and product developments over the past 12 months. Such vendors are used to working closely with the analog world, so sensors are a natural area for them.
One interesting trend has been the emergence of IoT development kits that includes sensors. An example along those lines is TT Electronics’ S-2CONNECT Pro Tracking and Monitoring Kit for rapid IoT development. The kit can be deployed to connect, track, sense and monitor applications such as asset tracking, cold chain, smart home and broader industrial IoT scenarios (Figure 1). The kit includes hardware from the TT Electronics S-2CONNECT family, including the S-2CONNECT Hub and S-2CONNECT Sense device, which incorporate temperature, humidity, light and acceleration sensors. An embedded SIM with three months of cellular connectivity, a data package of 25MB per month and a power supply is also included.
The Pro Kit comes with access to cloud-based services provided by TT Electronics including database, MQTT broker, microservices and firmware hosting. Access to the user interface for managing device configuration, provisioning and monitoring is offered exclusively by the S-2CONNECT Portal for the duration of the subscription.
PUBLISHED IN CIRCUIT CELLAR MAGAZINE • OCTOBER 2021 #375 – Get a PDF of the issue
MEMS Humidity Sensor Boasts Small Footprint
The BPS240 series from Bourns is a humidity sensor based on microelectromechanical systems (MEMS) technology. The BPS240 series offers upgraded features compared to Bourns BPS230 humidity sensors. The enhanced features include a faster response time of less than one second with digital (I2C) output. It delivers reliability in a small size (2.0mm × 2.0mm × 1.25mm) footprint.
• -0.3V to 7.0V supply voltage
• I2C communication protocol
• Measurement detection range: -30°C to +100°C
• Typical RH accuracy 2%
• Sleep current: 10 nA typical, 400nA max.
• Average operating current: 4.8µA typical, 10µA max.
• Size: 2.0mm × 2.0mm × 1.25mm
Magnetic Current Sensor Targets Industrial Applicationd
Infineon Technologies’ XENSIV TLI4971 is a high precision miniature coreless magnetic current sensor for AC and DC measurements with analog interface and dual fast over-current detection outputs. Infineon’s Hall technology enables accurate and highly linear measurement of currents with a full measurement range up to ±120A. The current sensor is equipped with internal self-diagnostic feature.
• Integrated current rail with typical 225µΩ insertion resistance
• SMD package, 8mm × 8mm
• Single supply voltage: 3.1V to 3.5V
• Accurate, scalable DC and AC current sensing
• Typical bandwidth of 240kHz
• Very low sensitivity error over temperature (max. 2.5%)
• High robustness to voltage slew rates up to 10V/ns
• Galvanic functional isolation up to 1150V peak VIORM.
• Precalibrated sensor
Dynamic Gesture Sensor for Cars Uses Infrared
The MAX25405 from Maxim Integrated is a low-cost, data-acquisition system for gesture and proximity sensing. Detection distance is improved by integrating a complete optical system consisting of lens, aperture, visible light filter and a 6×10 photodetector array. The MAX25405 recognizes a variety of independent gestures, including hand swipes, air clicks, flicks and more.
• Supports swipe, rotation, and proximity gestures
• Integrated lens, aperture, and filter
• 60-pixel IR photodiode array
• Integrated LED driver
• 400kHz I2C and 6MHz SPI serial interfaces
• Operates in 120k lux ambient light
• AEC-Q100 qualified
• -40°C to +85°C operation
• Compact 4mm × 4mm × 1.35mm, 20-Pin, side-wettable QFN package
Refrigerant Gas Sensor Serves Diverse Applications
The Molecular Property Spectrometer (MPS) R-290 Propane sensor from NevadaNano is well suited for residential and commercial R-290 propane applications including air conditioning, vending machines, commercial refrigeration racks and clothes dryers. The MPS Propane Sensor accurately reports 0-100% LEL and requires no field maintenance over their expected lifetime of 10 to 15 years.
• Meets UL 60335-2-40 and ASHRAE 15 requirements
• Wide environmental operating range
• No cross-sensitivity to rapid temp. and RH changes
• No false positives
• Extremely fast response time
• Immune to poisoning
• 10+ year calibration interval, 10+ year lifetime
• Built-in self-test for fail-safe operation
• Industrial and residential packaging options
Hi-Res Image Sensors Offer 16MP and 65FPS
ON Semiconductor’s XGS 16000 is a 16 Mpixel (MP) sensor that provides global shutter imaging for factory automation applications including robotics and inspection systems. Consuming only 1W at 65 frames per second (FPS), the XGS 16000 delivers exceptional performance at low power. It also offers one of the highest resolutions available for standard 29mm × 29mm industrial cameras.
• Advanced 3.2µm global shutter pixel
• High resolution with high image quality and uniformity
• Energy efficient design enables reduced power and thermal footprints
• Compatible with 29mm × 29 mm camera design
• 1:1 (square) aspect ratio
• 163-pin iLGA package
• Monochrome and Bayer color configurations
Outdoor Air Quality Sensor Features Ultra-Low Power
The ZMOD4510 gas sensor platform from Renesas Electronics detects air quality in a variety of indoor and outdoor applications. The module is a 12-pin LGA assembly that consists of a gas sense element and a CMOS signal conditioning IC. The module’s sense element consists of a heater element on a silicon-based MEMS structure and a metal-oxide (MOx) chemiresistor.
• Non-selective measurement of NO2 and ozone O3
• Selective O3 measurement using ultra-low power
• Supports international standards for air quality
• Ave. power consumption down to 0.2mW
• External reset pin (active-LOW)
• Siloxane resistant
• Operation temperature: -40 °C to +65 °C
• Standard version: 3.0mm × 3.0mm × 0.7mm
ToF Ranging Device Provides 64 Sensing Zones
STMicroelectronics' VL53L5CX is a time-of-flight (ToF), multizone ranging sensor. Housed in a miniature reflowable package, it integrates a SPAD array, physical infrared filters and diffractive optical elements (DOE) to achieve the best ranging performance in various ambient lighting conditions with a range of cover glass materials. The use of a DOE above the VCSEL allows a square FoV to be projected onto the scene.
• Multizone ranging output with either 4×4 or 8×8 separate zones
• Autonomous Low-power mode with interrupt programmable threshold to wake up the host
• Up to 400cm ranging
• Multitarget detection and distance measurement in each zone
• 60Hz frame rate capability
• 940nm invisible light and integrated analog driver
• 63-degree diagonal square FoV using DOE
• Low-power MCU running firmware
• Size: 6.4mm × 3.0mm × 1.5 mm
Dual LAN RK3328SBC has 40-pin GPIO
The HAR 3900 and HAR 3930 from TDK-Micronas are Hall-sensors that enable stray-field compensated position detection in automotive and industrial applications while addressing the need for ISO 26262 compliant developments. According to ISO 26262, the sensors are SEooC and ASIL B ready, enabling ASIL D developments on system level. They feature 3D magnetic-field measurement capability.
• Stray-field robust position detection
• Covers ISO 11452-8 requirements
• Real 3D magnetic field measurement of BX, BY and BZ
• Transmission of temperature-compensated raw magnetic-field values
• SEooC according to ISO 26262
• Supply voltage range: 3.0V to 5.5V (HAR 3900), 3.0V to 18V (HAR 3930)
• Temperature range: -40°C to 160°C
• Dual-die SSOP16 SMD package
Relative Humidity Sensors Deliver High Reliability
Texas Instruments' HDC302x is an integrated capacitive based relative humidity (RH) and temperature sensor, which provides high accuracy measurements over a wide supply range (1.62V to 5.5V). Both the temperature and humidity sensors are 100% tested and trimmed on a production setup that is NIST traceable and verified with equipment that is calibrated to ISO/IEC 17025 standards.
• Operating range: 0% to 100%; Accuracy: ±1.5% typical
• Drift correction; Long-term drift: 0.21% RH/year
• Condensation protection with integrated heater
• Average current 0.7µA
• I2C interface compatibility up to 1MHz speeds
• Four selectable I2C addresses
• Command/data protection through CRC checksum
• Supply voltage: 1.62V to 5.50V
• Available auto measurement mode
Jeff served as Editor-in-Chief for both LinuxGizmos.com and its sister publication, Circuit Cellar magazine 6/2017—3/2022. In nearly three decades of covering the embedded electronics and computing industry, Jeff has also held senior editorial positions at EE Times, Computer Design, Electronic Design, Embedded Systems Development, and COTS Journal. His knowledge spans a broad range of electronics and computing topics, including CPUs, MCUs, memory, storage, graphics, power supplies, software development, and real-time OSes.