A Monolithic GaN-Based LLC-SRC With Sub-1 mA Quiescent Current and 98.6% Peak Efficiency for Energy Star Standard and 80 Plus Titanium Standard

The proposed GaN-based hybrid gate driver (HGD) consists of two types of inverters and achieves a low quiescent current (IQ) of 23.2μA with a fast-operating frequency of 25MHz. At the same time, the automatic pre-charge technique (APC) senses the voltage of the bootstrapped capacitor and reduces the standby mode leakage current (ILKG) from a few milliamps to 62μA. Therefore, the efficiency is greater than 92% at the entire output load. Finally, the soft startup clamping technique (SSC) limits the peak voltage from 2.51kV to 620V, reducing power consumption during soft-start and preventing 650V GaN devices from being damaged by high-voltage stress. As a result, the LLC converter achieves a peak efficiency of 98.6% and complies with the 80 Plus Titanium and Energy Star standards for power supply units.