February 2015

DocID026993 Rev 1

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AN4599

Application note

STEVAL-ISA132V1 24 V 300 W peak power resonant converter

by Riccardo Tosoni

Introduction

This application note describes the features of the STEVAL-ISA132V1 evaluation board at

24 V, 300 W peak power conversion.

The architecture is based on a single-stage LLC resonant converter without PFC using the

new L6699 resonant controller.

The L6699 integrates some very innovative functions such as self-adjusting adaptive dead

time, anti-capacitive mode protection and a proprietary "safe-start" procedure which

prevents hard switching at start-up.

Thanks to the chipset used, the main features of this power supply are:

– very high efficiency under high-load and low-load conditions

– safe start up procedure to avoid hard switching

– hard switching prevention under overload and low-load conditions

– burst mode under low-load conditions with smooth restart to prevent audible noise

– the demo board can deliver more than 300 W peak power for a limited time thanks to

the NTC thermal protection positioned near the output diodes.

– continuous power at 30°C ambient temperature is 170 W.

– the MOSFET and diode power devices are in D²PAK packages

Figure 1. STEVAL-ISA132V1 300 W peak power SMP evaluation board

www.st.com