Engineering Knowledge Base
Turn complex specifications into actionable engineering decisions for selection, replacement, and evidence review.
How to Measure Conducted Emission: the Three Roles of the Line Impedance Stabilisation Network, Separating Common and Differential Mode, and Sizing a Filter from the Excess
Conducted emission is the easiest electromagnetic compatibility test to set up and the easiest to get wrong. It measures the noise a product pushes back into the mains between one hundred and fifty kilohertz and thirty megahertz, and the result depends strongly on the impedance of the supply, so the same unit reads differently in a different socket. The line impedance stabilisation network exists to remove that variable. It isolates mains noise, presents a defined impedance to the equipment under test, and couples the disturbance voltage to the measuring receiver. This article explains its three roles and the meaning of the fifty microhenry inductor, gives the method for separating common mode and differential mode paths, explains the difference between quasi peak and average detection, ties together the full chain from excess level to required filter insertion loss, and closes with the set-up points of a pre-compliance test and four common mistakes.
Power Supply Transient Testing and Control Loop Stability
A power supply's ability to recover from a sudden change in input voltage or load current depends on its control loop, power stage, and the parasitic elements i…
EMI Induced Error and Input Filtering in Precision Analog Front Ends
A precision amplifier with low offset, noise, and drift can still develop an output error far beyond its datasheet dc limits when radio-frequency energy reaches…
Understanding Inductors and Capacitors at High Frequency: From Ideal Components to RF Context
Understanding Inductors and Capacitors at High Frequency: From Ideal Components to RF Context Before discussing the high-frequency behavior of inductors and cap…
Low-Power Data Acquisition for High-Temperature Electronics
Low-Power Data Acquisition for High-Temperature Electronics Downhole oil and gas tools, aerospace systems, and automotive electronics can operate far beyond sta…
Can an Op Amp Really Achieve 1 ppm Accuracy? Error Sources and Design Techniques
Can an Op Amp Really Achieve 1 ppm Accuracy? Error Sources and Design Techniques As converters and measurement systems move toward ppm-level resolution, selecti…
Op-Amp Power-Sequencing Risks: ESD Diodes, Current Paths, and Protection
Op-Amp Power-Sequencing Risks: ESD Diodes, Current Paths, and Protection A dual-supply op amp may look straightforward in normal operation, but startup and shut…