The previous approach specified device timing in terms of data sheet specifications and simulation models. The syste

Low-power, high-accuracy pressure sensing for battery operated wearable devices

With more and more applications requiring high-accuracy atmospheric pressure data, engineers are seeking ever-more sensitive pressure sensing methods. New sensor technologies that are based on capacitive sensing enable engineers to create miniaturized and very accurate devices while satisfying demanding energy constraints and addressing reliability challenges.

Fitness monitoring wearables are a large part of a growing variety of products and applications require the high-accuracy sensing of static and dynamic air pressure. As these applications are typically found in batteryoperated devices, it is also essential to combine the high accuracy with optimized low-power operation and reliability across a broad range of operating conditions.

Many existing small form-factor MEMS (Micro Electro-Mechanical System) pressure sensors are built around piezo-resistive measurement techniques. In these cases, the flexing of a diaphragm in relation to changes in pressure is sensed via a strain sensor. However, piezo-resistive sensing elements are particularly susceptible to variation with temperature changes and they do not respond linearly to temperature. For this reason, piezoresistive sensors have a need for more complex calibration compared to a capacitive element. In addition, resistive measurement can represent a significant drain on power – a particularly important consideration when the target application is battery-powered and operating lifetime is critical.

By Sampo Härkönen, Senior Manager Pressure Sensor Marketing, Infineon Technologies

Download and read the full whitepaper below.

Also known as a Smart Trunk Opener (STO), the kick-to-open trunk application has grown significantly over recent years, especially in SUVs and high-end passenger vehicles. This feature allows the vehicle owner hands-free access to open the trunk with a simple kicking motion near the rear bumper.

Battery test equipment is used to verify battery pack functionality and performance prior to shipment to the customer. This Tech Note outlines three major functional tests that a battery tester performs while showing how to achieve the desired level of regulated error.

This document offers various implementations to achieve a full-bridge driver to excite an ultrasonic transducer when using the PGA460. Because the PGA460 was only designed to excite transducers in the transformer-driven or half-bridge driver modes, external circuitry is required to enable a full-bridge driver. The recommended solution is based on combining the functionality of the PGA460 with the DRV8870 to enable the excitation voltage to swing between ±45 V. Low-cost discrete alternatives are also discussed.

As a bridge of the link layer device medium access controller (MAC) and physical medium such as copper cable, the Ethernet physical layer device (PHY) integrates all the physical-layer functions needed to transmit and receive data on standard twisted-pair cables. Proper PHY configuration using management data input/output (MDIO) is fundamental during the prototype stage, and also crucial to meeting the requirements of lowest deterministic latency and fastest link detection in industrial Ethernet applications such as EtherCAT. This application report provides guidance on the Ethernet PHY configuration using the MDIO module within the Programmable-Realtime Unit Industrial Communications Sub-System (PRUICSS) in the Sitara device from TI, for industrial applications, by dissecting the PHY DP83822 configuration in EtherCAT on the AMIC110 Industrial Communications Engine (ICE). The goal of this application report is to expedite the development of industrial Ethernet applications on custom boards with migration and troubleshooting guides for the PHYs.

CLASS-D audio amplifiers provide output power with an efficiency of over 90% as compared to CLASS-AB amplifiers that can provide an output efficiency of <50%. CLASS-D amplifiers are implemented in portable personal audio systems that provide quality sound output enabling longer battery life. A widely used CLASS-D amplifier in automotive systems are for E-call systems that provide critical audio feedback to the driver in case of a driver emergency. In E-call systems discrete current sensing is often implemented for continuous diagnostics to ensure speaker is operational at all times.