The conceptually simple idea to determine current by measuring voltage across a known resistor shows the subtle nature of design tradeoffs. Part 1 of this article looked at one important aspect of the choice of resistor value in current-sensing applications, but it was only the electrical impact. However, the thermal impact related to resistor I2R […]
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A tradeoff case study: Sizing the current-sense resistor, Part 1
The conceptually simple idea to determine current by measuring voltage across a known resistor shows the subtle nature of design tradeoffs. There’s probably no phrase that misrepresents the realities of engineering design other than “hey, that should be no big deal.” Even simple-looking design decisions are often not so simple. The reality is that a […]
Basics of board-mounted dc/dc converter reliability
The reliability of board-mounted dc/dc converters is important to understand and quantify. It’s a measure of the frequency of system or device failures as a function of time. Reliability is the observed failure rate and is defined as either the time between two failures (in hours), called the Mean Time Between Failures (MTBF), or the […]
EMC/EMI design and the use of board-mount dc/dc converters
Electromagnetic compatibility (EMC) and electromagnetic interference (EMI) are system-level considerations that have implications for power system design, especially when multiple board-mounted dc/dc converters are used in a distributed power architecture (DPA). EMC/EMI is a multidimensional consideration and includes differential- and common-mode noise on both the input and output of the converter radiated and conducted noise […]
Thermal management considerations for board-mounted dc/dc converters
System-level thermal design is equally important to the electrical specifications of board-mounted dc/dc converters. And the growing use of variations on a distributed power architecture (DPA) increases the complexity of thermal design. A single multiple-output ac/dc power supply is used to power the various loads in a conventional power architecture. The use of a centralized […]
PMBus 2.0 expanding PMBus for future system needs: Virtual Interview, part 2 of 2
We are here today with Bob White, the PMBus power management protocol’s originator, long time chair of the PMBus specification working group, and current editor of the PMBus and SMBus specifications. Bob is the principal author of the PMBus specifications and continues to participate in the PMBus Specification Working Group. He is a well-known speaker […]
PMBus® update, what changes lie ahead? Virtual Interview, part 1 of 2
We are here today with Bob White, the originator of the PMBus power management protocol, long time chair of the PMBus specification working group, and current editor of the PMBus and SMBus specifications. Bob is the principal author of the PMBus specifications and continues to participate in the PMBus Specification Working Group. He is a […]
Specifying board-mounted dc/dc converters
The specification of board-mounted dc-dc converters is an important and detailed process. Correctly implemented, it results in a cost-effective solution that meets all the needs of the application. Incorrectly specified dc/dc converters can result in a more costly device than necessary and/or a device that is not suited for the application. This FAQ will review […]
The basics of AC-line isolation for safety, Part 2: The solution
Isolation from the AC line is essential for user safety in many situations and can be implemented using a special isolation transformer as well as other means. Part 1 of this FAQ looked at the multiple-fault and failure scenario that can put users at risk from AC-line connected products, including appliances, instruments, or medical devices. […]
The basics of AC-line isolation for safety, Part 1: The challenge
Isolation from the AC line is essential for user safety in many situations and can be implemented using a special isolation transformer as well as other means. “Isolation” is one of those terms which gets tossed around and is often cited as an almost universal, all-purpose cure for various ongoing or possible circuit and system […]
