4.5 Eliminate High-Frequency Switch-Node Ringing and Pass CISPR 25 Class 5 without Metallic Shielding or a Common-Mode Choke


Date: September 11, 2017

EMI mitigation is commonly one of the most challenging aspects of a power supply design. This challenge is amplified in the automotive world, where meeting stringent CISPR 25 Class 5 standards are often mandatory. The LMS3635-Q1 and LMS3655-Q1 synchronous buck converters aid in the process of optimizing for EMI in several ways:

1) By eliminating wire-bonding in the package, parasitics that cause high-frequency switch-node ringing are also eliminated

2) A symmetrical and thoughtful pin-out enables the minimization of the size of the current loops

3) Spread spectrum lowers the peak radiated and conducted emissions

Watch as Katelyn uses the TIDA-01388 dual USB reference design to demonstrate how these devices pass CISPR 25 Class 5 without the use of metallic shielding or a common-mode choke. 

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