Optimized Design of Integrated PCB-Winding Transformer for MHz LLC Converter

Optimal design of high frequency high efficiency and high‐power density DC–DC power module based on GaN

“…If combined with the switching devices selection, topology design and efficiency utilization of magnetic core, the efficiency and power density of the power module can be greatly improved. To achieve this design goal [15], A two‐stage topology is proposed to realize voltage conversion and the main power switching devices are gallium nitride [6]. The first stage of the power module adopts two‐phase coupled interleaved buck technology convert the wide voltage (dc 60–dc 160 V) into the constant intermediate bus voltage 48 V, the switching frequency of the converter is about 750 kHz, Under the condition of standard input voltage dc 110 V, buck converter always works in CRM state, buck converter is the easiest to achieve ZVS in CRM mode, the buck converter conversion efficiency reaches the peak.…”

“…Due to the interaction between the coupled inductance winding, the slope given by the reverse coupling equation no longer matches the assumed inductance value L, simple U = L*dI/dt no longer applies. Only by redefining the inductance, the equivalent inductance of the four states, namely L A , L B , L C and L D can derivation based on L = U*dI/dt, the equivalent inductance equation of the four states and corresponding current slope can be deduced [14][15][16][17][18].…”

“…American's Bel-fuse (0RQB-C5W24R-1839HZ), the current most advanced power module as a reference standard, which adopt metal-oxide-semiconductor field-effect transistor as switching devices, use single level topology architecture, the size is a quarter standard package, the peak efficiency can reach 95% [26]. To make a fair comparison, taking the current most advanced power module as the standard, in the same package and same size of the case, using two-level topology structure, and gallium nitride as a switching device develop a power module [8][9][10][11][12][13][14][15]. Here, the current most advanced power module (American's Bel-fuse) is analyzed in detail, including topology selection, efficiency, advantage and disadvantages [19,20].…”

“…The first stage circuit architecture uses a two-phase interleaved buck converter to convert the wide range voltage into a constant intermediate bus voltage (48 V) through closed-loop control, and then the LLC resonant converter converts the intermediate bus voltage (dc 48 V) into a constant output voltage (dc 24 V) through open-loop control, and realize the primary side and secondary side dc 3000 V electrical isolation. This article from the circuit topology, the power devices selection, buck converter magnetic integrated coupling inductance design, planar magnetic integration LLC resonant transformer optimization design has carried on the detailed analysis [15]. All circuits are integrated in a standard quarter power brick module, the final prototype can reach 96.1% peak efficiency, and the power density can reach 185 W/in.…”

Review of High-Frequency High-Voltage-Conversion-Ratio DC–DC Converters

“…The transformer needs a large turns ratio and it suffers the total voltage conversion pressure. Besides, due to package and thermal constraints, it is necessary to connect synchronous rectifiers (SRs) in parallel, which is difficult to arrange close to the terminal, and causes large leakage inductance and winding losses as well [15]- [16]. To deal with this issue, the transformer can be split into several smaller ones.…”