Sensors Converge displays advances in sensors

The Sensors Converge 2023 conference, held June 20-22, showcased the latest advances in sensor and sensing solutions. New products ranged from radar sensors and ultra-wideband (UWB) proximity sensors to inertial measurement units (IMUs) and all-in-one sensor modules.

These advancements target a variety of applications, including automotive, industrial and consumer electronics.

Sensor trends continue to focus on reducing system complexity and shrinking solution and package sizes. A big area of development is integration, which contributes to greater design flexibility, lower system complexity and smaller footprints.

Here is a sampling of sensor innovations featured at this year’s show.

Automotive and industrial sensors

Socionext Inc. featured its millimeter-wave integrated radar solutions for optimizing in-cabin automotive applications, including the debut of its automotive-grade SC1260 series of intelligent, ultra-low-power CMOS 60-GHz radar sensors. Designed to improve vehicle occupant safety and enhance the overall driving experience, the all-in-one radar sensors enable easy acquisition of three-dimensional (3D) positions without requiring advanced expertise in high-frequency devices and signal processing, according to Socionext.

The all-in-one configuration incorporates antennas and radar signal processing circuits for maximum detection accuracy in an ultra-compact FC-BGA package, measuring 6 × 9 × 1.2 mm.

For occupant detection and infant wellness monitoring, the 60-GHz radar sensors are designed for high-precision in-cabin sensing with time-division multiplexing (TDM-MIMO), enabling a single sensor to detect multiple passengers seated in a row. The sensors offer the capability to differentiate pets from humans and monitor vital signs such as heartbeat and respiration. In addition, the technology can detect infants wrapped in blankets or hidden from view, since radar can penetrate through solid non-metallic material, said Socionext.

“The high-precision sensors use a wide band of 6.8 GHz (57.1 to 63. 9GHz) with an expanded number of receiving antennas by TDM-MIMO processing and built-in radar signal processing circuits for range-finding and angle calculation,” said the company.

The radar sensors integrate antennas, wireless circuits, AD converters, FIFO memory, a SPI interface and an intelligent power control sequencer. Power consumption is 0.72 mW at 0.1% duty cycle operation and the operating temperature range is -40°C to 125°C.

The radar sensors also can be used for anti-theft monitoring, surrounding the vehicle, including pre- and post-collision video recording. The radar sensor can operate 24/7 uninterrupted using only 1 mW of power. “Automotive dashcam systems using Socionext’s radar sensor can detect incoming vehicles and record an incident prior to the occurrence,” said the company.

The smart sensor also provides 3D hand gesture recognition to operate in-vehicle displays and infotainment systems. SC1260 sample and evaluation kits are available and will be followed by production volumes in the first quarter of 2024.

TDK Corp. has expanded its SmartIndustrial sensor platform family with the high stability IIM-20670 six-axis IMU with an extended temperature range and high vibration rectification error (VRE) performance. Consisting of a three-axis accelerometer and three-axis gyroscope, the MEMS industrial IMU offers high stability, high vibration immunity and the capability to simultaneously measure all six axis with a current consumption below 10 mA under all operating conditions.

Targeting industrial applications that require “extreme” stability over temperature and high vibration immunity, the IIM-20670 is calibrated over multiple temperature points and offers an extended temperature range of -40°C to 105°C.

The industrial IMU provides an accelerometer thermal stability of 45 ug/C, an accelerometer bias repeatability of 1 mg and a programmable output of 64 G together with a tilt algorithm that outputs pitch and roll data over the full temperature range. Gyroscope thermal stability is 1.7 mdps/C. Other key features include an operating voltage range of 1.71 to 3.6 V, programmable digital filters and a 10-MHz SPI interface with a CRC-based error-detecting code algorithm.

TDK said these specifications allow the IIM-20670 to provide one of the most stable six-axis tilt outputs in the industry and makes them well suited for applications that need fast and accurate tilt or stabilization performance such as 5G platforms, Industrial tilt modules and industrial/agricultural drones.

The IIM-20670 is housed in a QFN package, measuring 4.5 x 4.5 x 1.1 mm. It is available for evaluation and through distribution partners worldwide by the end of July 2023.

Environmental and energy-saving sensors

Infineon Technologies AG announced the XENSIV PAS CO2 sensor has passed the performance requirements defined by the internationally recognized WELL and LEED green building certifications. Qualification was confirmed by a strategic assessment, conducted by the GREENMAP organization, accredited for WELL performance testing and a LEED provider.

The XENSIV PAS CO2 sensor meets five WELL features (e.g., ventilation design, air quality monitoring and awareness), and six LEED credits (e.g., optimized energy performance and enhanced indoor air quality strategies). These qualifications enable buildings to earn a maximum of 28 points for LEED and up to six points for WELL certifications.

Environmental sensing is a pillar in Infineon’s software-driven sensor solutions. The XENSIV PAS CO2 is a CO₂ sensor based on photo-acoustic spectroscopy (PAS) technology.

Infineon said non-dispersive infrared (NDIR) has been considered the state-of-the-art technology for CO₂ sensors. Now, the XENSIV PAS CO2, based on PAS technology, officially meets the sensor technology requirements approved by WELL and matches the performance of high-end NDIR solutions in a four times smaller size, said the company.

The XENSIV PAS CO2 sensor provides real-time measurements for indoor air quality to help maintain a healthy indoor environment. This real-time data output can be used to remove CO₂ pollutants and improve indoor air quality through demand-controlled ventilation, resulting in up to 30 percent energy savings as well as higher levels of comfort, well-being and productivity, said Infineon.

Housed in a small module, the sensor integrates a PAS transducer (MEMS acoustic detector, infrared source and optical filter), a microcontroller for signal processing and algorithms and a MOSFET chip to drive the infrared source. The integrated microcontroller performs ppm calculations, advanced compensation and self-calibration algorithms.

The small size of the XENSIV PAS CO2 reduces space requirements by more than 75 percent compared to other commercially available real CO₂ sensors, according to Infineon. The XENSIV PAS CO2 sensor is available now.

Novelda AS debuted its ultra-low-power UWB proximity sensor at the conference. Claimed as the lowest power UWB radar sensor, the device operates on batteries with a low power consumption of less than 100 microwatts (µW) for high energy efficiency.

Novelda calls the ultra-low power consumption, which helps extend battery life and reduce overall carbon footprint, a “breakthrough achievement,” which “sets a new standard for energy-efficient radar technology while offering high performance, able to detect breathing motion at 10 meters.”

The ultra-low-power UWB proximity sensor features a small form factor, delivering a complete sensor module with antennas and on-chip processing in a 5 × 30-mm package. The UWB sensor is worldwide compliant, enabling the module to be used globally.

Other key features include a fully configurable detection zone, allowing customers to define the detection zone for their specific requirements, and easy integration behind materials such as plastics, tempered glass and ceramics, enabling space-constrained designs such as thin bezels. The technology also offers “excellent” co-existence properties and is not impacted by Wi-Fi and Bluetooth or other UWB devices and radars, said the company.

The new radar system provides accurate angle and distance information to multiple targets, which enables complex use cases such as people estimation, said Novelda. The sensor offers absolute range limitations and can be set to ignore passing targets.

One example cited is a kiosk application, where only the intended users activate the welcome screen. The screen enters low-power mode when unoccupied, extending LCD screen life by up to approximately 10 years, according to Novelda.

Samples of the ultra-low-power proximity sensor will be available in the third quarter of 2023, with the final product launch in mid-2024.

Consumer sensors

TDK also announced an upgrade to its InvenSense SmartBug all-in-one IoT sensor module. The new InvenSense SmartBug 2.0 replaces the ICM-42688-P IMU with the machine-learning-enabled ICM-45686-S IMU, the lowest power IMU (220 µA @ 50 Hz 6-axis) from the BalancedGyro family. Applications include TWS, AR/VR/MR glasses and wearables.

The key feature of SmartBug 2.0 is the introduction of ML, enabling developers to use the SmartBug 2.0 with the company’s sensor inference framework (SIF) to build ML solutions for the ICM-45686-S IMU, said TDK.

The SIF software enables users to collect IMU sensor data, select custom features, build ML models, test performance, deploy and run those models on the ICM-456xy IMU through the SmartBug 2.0. This allows users to develop custom motion classification algorithms and run them on the 2.5 × 3 mm IMU at a current consumption as low as 30 µA. Examples cited include algorithms such as exercise classification (squats, jumping jacks, lateral raises and push-ups) and wrist gesture classification (fight, clench, shake and still mode).

Other improvements include the addition of TDK’s head tracking solution (VibeSense360) for TWS and AR applications, the enhanced Air Motion solution that adds swipe gestures, remote orientation gesture and accurate cursor tracking for smart TV remotes and updated streaming and logging parameters in SmartBug to enable longer duration streaming and logging of multi-sensor and algorithm data.

SmartBug 2.0 also retains the user interface, BLE, Wi-Fi, USB and SD card logging and previous applications such as asset monitoring, smart door lock and sensor fusion. SmartBug 2.0 is available now for evaluation with mass availability at the end of August.

Demos

Many sensor companies also showcased and demoed their most recent sensor product launches, including Blickfeld, Excelitas, Posifa, STMicroelectronics and TT Electronics.

Blickfeld GmbH showcased its Smart LiDAR Qb2 for the first time at the show. Called an industry-first Smart LiDAR sensor, it enables the capturing and processing of 3D data on a single device. The integrated compute module allows the company’s Percept software stack to run on the device, providing users with real-time data for a variety of applications, such as volume monitoring, crowd analytics and smart infrastructure.

Excelitas Technologies Corp. showcased its CaliPile TPiS 1T1386 L5.5H thermopile sensor. The company claims that the new CaliPile sensor delivers the highest temperature accuracy combined with configurable threshold functions and lowest power consumption currently available. Used for remote skin-temperature measurement applications and liquid and gas temperature control in medical applications, the thermopile sensor delivers fast remote over-temperature protection, mid-field human presence sensing, far-field human motion detection, and passive light-barrier sensing for people counting.

Posifa Technologies highlighted several advanced technologies, including hydrogen sensors and vacuum gauges, which offer advanced detection capabilities. The company demoed its solutions for detecting thermal runaway in battery management systems (BMS) and refrigerant leaks in HVAC systems. Built on the company’s MEMS hydrogen sensor technology, these solutions accurately detect hydrogen concentration in the air by measuring the change in thermal conductivity of the gas mixture within BMS and HVAC compartments.

The company also displayed its MEMS Pirani gauges for atmosphere (ATM) to medium vacuum applications that offer high accuracy, wide measurement ranges, longevity and long-term stability. By incorporating the sensing element and digital electronics within an individually calibrated probe, the vacuum gauges eliminate the need for calibration of replacement probes, Posifa said.

The devices can be customized to emulate output voltages from other manufacturers’ gauges for easy plug-and-play replacements without hardware or software changes.

STMicroelectronics showcased a wide range of sensors. For industrial applications, the company highlighted its ILPS28QSW waterproof pressure sensor,  housed in a sealed, cylindrical, surface-mountable package and ISM330ISN inertial measurement unit (IMU).

STMicroelectronics claims the ILPS28QSW is the first MEMS water/liquid-proof absolute pressure sensor, targeting the industrial IoT market, with a 10-year longevity program. Applications include gas and water metering equipment, weather monitors, air-conditioning smart filters and home appliances.

The ISM330ISN targets edge-based industrial applications such as robotics, condition monitoring and asset tracking. It features a new ST category of processing, called intelligent sensor processing unit (ISPU) to support real-time applications that rely on sensor data. The ISPU is an ultra-low-power, high-performance programmable core that can execute signal processing and AI algorithms in the edge.

ST also featured its latest advances in motion sensors, the LIS2DUX12 and LSM6DSV16 , which included a preview of its new SensorTile.box PRO. The ultra-low-power LIS2DUX12 is a smart, digital, 3-axis linear accelerometer with features such as always-on anti-aliasing filtering, a finite state machine (FSM) and machine learning core (MLC) with adaptive self-configuration (ASC). Applications include wearable devices, game controllers, hearing aids, portable healthcare devices, true wireless stereo and asset trackers.

The LSM6DSV16BX is a highly integrated sensor that delivers space savings in hearable devices including sports and general-purpose earbuds. The all-in-one motion and bone-conduction sensor combines a six-axis inertial IMU for head tracking and activity detection with an audio accelerometer for detecting voice through bone conduction in a frequency range that exceeds 1 KHz.

Also on display were the VD55G1 and VD56G3 image sensors for computer vision. Demos included time-of-flight for AI applications, AR glasses augmented with ST image sensors and intelligent sensing.

TT Electronics featured its portfolio of optoelectronic sensors, highlighting its FlexSense optical encoder sensors, the FS210 and FS310. The FS210/FS310 programmable incremental encoders integrate an optical sensor array that can be programmed to operate with a wide range of codewheel diameters, including linear strips and resolutions. The FS310 adds a near-IR LED.

Key features include auto-alignment, a closed-loop LED driver, on-chip diagnostics, a state-of-the-art 8× interpolator and adaptability to multiple code-disk diameters and pulses per revolution. Demos showed how easy it is to re-calibrate the FlexSense chip to meet application requirements.