STMicroelectronics STNRG328S Digital Controller for STC/HSTC open-loop resonant converters is developed for power conversions. The device achieves a power conversion from an input voltage in a typical range of 40V to 60V to an output voltage with a programmable conversion ratio from 2:1 to 10:1 with a fixed duty cycle and programmable frequency from 140kHz to 300kHz.
The controller supports an output power in the range of 500W to 2KW with extremely high efficiency in a wide load range and an efficiency peak of 98.4%.
The State Machine Event Driven (SMED) implements vital features to provide all the STC/HSTC control functions. The SMED drives the ZCD feature permitting management of the deadtime and the switching frequency to accomplish the perfect LC resonance and top efficiency independently from the external component variations. The device firmware is particularly designed to program the SMED and implement the control strategy.
The device combined with the STPRDC02A gate drivers, created for STC applications, and a hot-swap circuit (typically an e-fuse) evades damages during hot plug-in of the input 48V bus.