May 11, 2017
High-frequency conducted and radiated emissions from power converters occur based on the transient voltage (dv/dt) and transient current (di/dt) generated during hard switching. Such electromagnetic interference (EMI) is an increasingly complex issue in the design and qualification cycle, especially given the increased switching speed of power MOSFETs.
1.EMI overview and fundamentals
–EMI noise coupling paths (DM & CM)
–EMI standards: EN55022 class B (industrial, comms), CISPR 25 class 5 (automotive)
–EMI measurement setup & LISN schematic
–EMI filtering, DM & CM equivalent circuits, CM noise propagation paths
2.EMI noise sources and mitigation
–“Hot” loops, parasitic inductance, magnetic fields
–SW node harmonics & voltage ringing, electric fields
–Circuit and layout techniques for EMI mitigation
3.EMI management in DC/DC converters
–Component placement, GND plane management, PCB stack-up strategies, etc.
–Practical circuit examples, EMI performance-optimized PCB layouts, EMI results
LM5145: VIN = 6V to 100V, VOUT = 5V, IOUT = 20A [PCB layout, input caps, inductor selection]
LM53635-Q1: VIN = 3.5V to 42V, VOUT = 5V, IOUT = 3.5A [HotRod package, SSFM, PCB layout]
Date: November 14, 2019
1Concepts of switching regulator EMI and noise mitigation (4)
This section discusses EMI, noise and ripple with a more conceptual approach to serve as a primer for the rest of the series.
2EMI and noise mitigation techniques in practice (5)
In this section, we will examine the impacts of various mitigation techniques to help you decide which approach makes the most sense in your design.
3Achieving low noise and high efficiency for noise-sensitive analog loads (1)
In this section, we will discuss what types of signal chain loads can be driven directly by a switching regulator to get low noise and EMI.
4Low EMI and low noise DC/DC conversion in automotive applications (6)
Learn more about how to use low EMI and low noise DC/DC conversion in automotive applications.