The MOSFET solution for in car charging is a vehicle grade device selection and system optimization solution for the full power link of in car chargers (OBCs). The core focuses on three major goals: high efficiency, high power density, and vehicle grade reliability, covering the entire process of front-end PFC, high-frequency isolated DC-DC, synchronous rectification, and safety management.

Core topology phased device scheme
1. Pre stage PFC boost link
As the first level of AC to high-voltage DC conversion in the power grid, the core requirements are high voltage resistance, low switching losses, and adaptability to Vienna rectification or interleaved Boost topologies:
SiC high voltage solution: Basic semiconductor B2M040120R, 1200V/40m Ω, reduced switching loss by 30%, supports high frequencies above 200kHz, significantly reduces the volume of magnetic components
Silicon based robust solution: VBP19R20S, 900V/20A, SJ_Sulti-EPI technology, 205m Ω low on resistance, providing sufficient surge margin for 800V bus
Vehicle regulation certification: All components meet the AEC-Q101 standard, with a working junction temperature coverage of -55 ℃~175 ℃

2. High frequency isolated DC-DC conversion link
LLC resonant or phase-shifting full bridge topology, with core requirements of high-speed switching and low gate charge:

SiC Preferred Solution: Nexperia NSF080120T2A1-Q, 1200V/80m Ω, with Kelvin source pin, suppresses switch oscillation, compatible with V2G function of bidirectional OBC
Silicon based high-frequency solution: Infineon IAUZN04S7L046, 40V/4.59m Ω, OptiMOS ™ 7 processes, Qg only 12nC, new model released in 2024, supply cycle stable until 2038

3. Secondary synchronous rectification link
In high current scenarios, extremely low on resistance is the key to improving efficiency:

High current solution: VBGL7802, 80V/250A, TO-263-7L package, Rds (on) as low as 1.7m Ω, full load efficiency can be improved by 1-2%, requiring Kelvin connection to eliminate source parasitic inductance
Compact layout solution: VBQD5222U, dual N-channel integrated in DFN8 package, single-chip for bidirectional control, significantly reducing PCB footprint

4. Safety and pre charging management process
Replacing traditional relays to achieve fast on/off without arc:

P-channel solution: VBFB2658, ± 60V/-25A, TO-251 package, no need for additional isolated driver power supply, used for output side pre charging and fault millisecond level cut-off
12V system solution: Ansenmei FDWS86380-F085, 80V/11.3m Ω, DFNW8 package, with wettable side wings supporting AOI automatic detection, saving production line X-ray detection costs