Dissipation, Thermals, and Rds(on)

This article explores the significance of the Rds(on) specification of a MOSFET in a linear voltage amplifier and implications on Thermal Design - dissipation, thermal resistances, and heatsinking. It may be of interest to put this in perspective and highlight the connection between these subjects.

The popularity of acoustic cameras has exploded over the past three years, as applicability also increased with portable models. Evolving from large models used mainly in research, acoustic cameras are now compact and portable enough to become practical in daily inspection operations. Crysound, the largest audio test and measurement company from China, has now introduced the CRY8120 Series Acoustic Imaging Cameras, a breakthrough in industrial capabilities, also combining a thermal module.

The brand new generation of Beyma compression drivers originates from an intense R&D effort and two patent-pending innovations. Unveiled at ISE 2013, Beyma's four base designs with 2 throat sizes, 4 voice coil diameters, 3 diaphragm materials and 2 magnet types, allow for a total of 12 new models (for now). Scheduled to be launched progressively during 2023, these new Beyma state-of-the-art high frequency transducers deliver new exciting possibilities for speaker designs.

The latest development from Precision Devices International, following the seismic abilities of the 24-inch and 21-inch sub bass woofers launched earlier in June 2021, the new 18” PD.1845-1N introduces clear design refinements, resulting in an ergonomic, vented cast aluminum chassis that offers improved thermal control, also featuring an aluminum demodulation ring for ultra-low distortion. The 4.5" split winding copper clad aluminum voice coil and vented long-throw motor system leverages a voice coil gap for reduced power compression and an optimized double silicone suspension system for ultimate cone control.

Ansys released the new Ansys Discovery, a next generation, easier-to-use, product design software that the company says is its first simulation-driven design tool to combine instant physics simulation, Ansys' proven high-fidelity simulation and interactive geometry modeling into a single design exploration application. The new software is said to reduce engineering labor costs by 26%, enable evaluation of 60% more design alternatives, and slash physical testing and safety costs by 19%.

COMSOL announced the latest version of COMSOL Multiphysics Version 5.4, which in addition to two new products provides performance improvements and additional modeling tools. The latest version of COMSOL Multiphysics features COMSOL Compiler, giving specialists the freedom to distribute their simulation applications through executable files, and the Composite Materials Module for layered structures analysis. For acoustics modeling applications, the update introduces acoustic ports and nonlinear acoustics Westervelt model.

Linear Integrated Systems, a full-service manufacturer of specialty linear semiconductors, now offers the LSK 489, a 1.8-nV at 1-kHz, low-capacitance, N-channel monolithic dual JFET. The LSK 489 is part of a family of ultra-low-noise, dual JFETs specifically designed to provide users with less expensive solutions for obtaining tighter drain-source saturation current (IDSS) matching and better thermal tracking.