TIDUET3 February   2021

 

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2.4 System Design Theory

This reference design provides a universal AC, mains-powered, 500-W nominal output at 48 V. This design is derating to 300 W at a low line 115 VAC. The UCC28180 controls a PFC boost front end, while the UCC256403 LLC resonant half-bridge converts the PFC output to an isolated 48 V. The total system efficiency is 94.5% with a 230-VAC input and over 92.5% with a 115-VAC input at full load. In addition, several protections are embedded into this design, which include input undervoltage protection and output short-circuit protection. Low EMI, high efficiency, a high power factor, and a reliable power supply are the main focus of this design for targeted applications.