As modern bus interface frequencies scale higher, care must be taken in the printed circuit board (PCB) layout phase of a design to ensure a robust solution.

Power hungry electronic components such as CPUs, GPUs, or FPGAs, as well as voltage regulators heat up during operation. Some applications require ambient air temperature measurements while others need to measure the temperature of a nearby component on the PCB. Measuring ambient air temperature with a surface mount technology (SMT) device is challenging due to the thermal influence of other components within the system. In other systems, in which the temperature of a component needs to be measured, ambient air temperature can influence and degrade the measurement accuracy. The system designer needs to make certain design decisions regarding both package type and PCB layout when integrating a temperature sensor.

This application note provides recommendations to system designers and explains methods for improving the accuracy of the temperature point being measured. The Recommendations are provided both for air temperature measurements and for component temperature measurement. The report details layout techniques, device orientation, and best practices for mounting.

The ability to dynamically control current in an inductive load system is very important for stepper motor designs where different levels of torque control are desired. This adjustment feature can also be used to improve system efficiency by reducing the motor current in low-load situations, achieving a longer battery life.

This application report is provided as a supplement to the data sheet for the DRV8884, DRV8885, DRV8886 and DRV8886AT motor drivers. The goal of this document is to show how to achieve accurate current regulation in normal and low-power modes using different methods. This document also describes different sources of error in these configurations, how to minimize these errors, and the key factors to consider when doing a design.

This application report details the measurement principles for using an LC sensor to detect rotational movement. Based on this measurement principle, an example project is presented demonstrating contactless rotational measurement using the Scan Interface (Scan IF) of the MSP430FW42x family of devices. Software as well as hardware for the implementation is explained.

This application note presents the idea of achieving all-port isolation in an existing non-isolated RS-485-to-RS-485 communication link without delving into the details of the protocol between the nodes.

The strong interest in this application report prompted this third edition. In addition to the changes and updates made throughout these sections, this edition also discusses Local Interconnect Network (LIN), USB-On-the-Go, DisplayPort, digital isolators, and more. This application report serves as a reference tool for finding the most appropriate data bus solution for today ’s advanced system architectures. It gives an overview of the different bus solutions available from Texas Instruments. Designers can use many different solutions to solve the same problem. The task is to identify the optimum solution for their application.

This application report makes it easier for designers to do this. It has sections on data transmission fundamentals, data line drivers and receivers, data links, and data signaling conditioners. Subsections discuss the electrical properties, applicability, and features of each product family.

This application report discusses digital filters which are a ubiquitous feature in delta-sigma analog to digital converters (ADCs). Digital low-pass filters are essential to the functionality of a delta-sigma ADC, which relies on oversampling and noise shaping to push quantization noise out of band. There are variations between the types of digital filters used in delta-sigma ADCs that provide various benefits and drawbacks that orient them to different applications. The types of filters and the tradeoffs between them are discussed in this report.

This application report addresses high-speed signals, such as clock signals and their routing, and gives designers a review of the important coherences. With some simple rules, electromagnetic interference problems can be minimized without using complicated formulas and expensive simulation tools. Section 1 gives a short introduction to theory, while Section 2 focuses on practical PCB design rules. Either section can be read independently.

This application note describes methods that can be used to improve noise performance in systems using audio codecs. Noise is present in all circuit board systems; however, common design practices can help minimize overall noise contribution to improve the audio quality using audio codecs. Recommendations in this document apply to the TLV320AICxxxx, TLV320ADCxxxx, and TLV320DACxxxx audio converter families. Some information in this document may be used to reduce noise in other audio converter devices as well.

The most common thermocouple in use today is the Type K. A Type-K thermocouple is inexpensive, accurate, and works reliably in harsh environments. Type-K thermocouples can measure temperatures ranging from –200°C to +1250°C and have a Seebeck coefficient of S = 41 μV/K at room temperature.

In this application note we highlight the implications of ripple injection techniques, aimed at minimizing output ripple voltage, on the transient response of a supply. The results help choose a suitable ripple injection technique after striking a balance between the output ripple voltage and the transient response required by the load.

The Universal Serial Bus has become one of the most widespread and convenient ways to connect electronic devices to the PC. Countless modern portable products with built-in USB connectors readily use the USB data bus to transmit and receive data to and from PCs, but many of these battery-powered units still use a separate power supply for battery charging (often a charging cradle or a simple AC/DC converter). Sometimes overshadowed by its data bus partner, each USB connection also contains a power bus. With a maximum power rating 5.25V/500 mA, the USB power bus is a great source for charging a single-cell Lithium-Ion battery.

The LM5113 device is designed to drive the high-side and low-side enhancement mode Gallium Nitride (GaN) FETs in a half-bridge configuration. The floating high-side gate is capable of driving enhancement mode GaN FETs up to 100 V. Used with the DSBGA package the LM5113 device is especially suited for high-frequency operation. Care must be taken at high-frequency operation to ensure that adequate thermal design tolerance is present for the worst-case driver power dissipation. Furthermore, a good understanding of the driver losses for different load mechanisms is very helpful in estimating the on die power loss in the GaN driver. This application report demonstrates the operation of LM5113 device at high-frequency for hard-switching and soft-switching applications. It also provides an estimate of the losses in the driver based on calculations and an analytical approach.

This document describes the basic structure and operation of the digital micromirror device (DMD) array.

This document covers the basic structure and operation of DMD devices. The DMD is a unique combination of opto-mechanical and electro-mechanical elements. The journey begins with understanding how one pixel works and building on that to encompass the entire array of pixels that comprise a DMD.

This application report describes the implementation of a low-cost three-phase electronic electricity meter using the Texas Instruments MSP430F67641 metering processor. This application report includes the necessary information with regard to metrology software and hardware procedures for this single-chip implementation.

This design example consists of a single string of ten LEDs driven with 1-A forward current. This design example is a supplement to the TPS92510 data sheet and provides step-by-step instructions for optimizing an LED driver design. In particular, detailed attention is given to compensating and measuring the feedback loop, implementing the thermal foldback protection, and designing the printed-circuit board layout. Graphs are provided showing the design example test data.

Bridgeless power factor correction (PFC) topology is attracting attention as a means of satisfying the new high-efficiency requirements. This application report reviews the UCC28070 and its design considerations for bridgeless PFC. It present a bridgeless solution that is relatively easy to implement in that it does not require any additional circuitry for current sensing and that the operation remains very similar to that of a conventional concinuous condustion mode (CCM) PFC.

This application note introduces an ARM hardware-based debugging tool, Serial Wire Output (SWO) Trace. The discussion starts with background information on what happens at a hardware level, to explain what the many capabilities are. Then, it focuses on how the tools are implemented in the TI Code Composer Studio (CCS) integrated development environment (IDE), compared to other IDEs.

In CCS, the SWO Trace tools are presented in the form of three main use cases: Statistical Function Profiling, Data Variable Tracing, and Interrupt Profiling. A fourth, Custom Core Trace, lets the user customize what triggers are set and what events are recorded by the hardware.

This application note explains how to use SWO Trace in CCS (called Hardware Trace Analyzer), demonstrate with a simple Out of Box example, and explain further configuration and customization. By using this application note as a guide, users should be able to implement the Hardware Trace Analyzer debugging tools in CCS to view the large projects in smaller parts to fully understand what is happening.

This document provides an overview of barometric pressure sensing, digital air pressure sensor and use cases.

The document is intended for Infineon customers who wish to develop applications based on DPS310 barometric pressure sensor.

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

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