STMicroelectronics’ New MDmesh™ MOSFETs with Fast-Recovery Diode Enhance Power Density of High-Efficiency Converters

The latest MDmesh™ DK5 power MOSFETs from STMicroelectronics are Very High-Voltage (VHV) super-junction transistors with the extra advantage of a fast-recovery diode . This helps designers maximize the efficiency of various power-conversion topologies including LLC resonant converters with Zero-Voltage Switching (ZVS).

As super-junction MOSFETs, the new devices — in voltage ratings from 950V to 1050V — deliver superior switching performance with lower on-resistance (R_DS(ON)) and higher current rating per die area compared to ordinary planar MOSFETs. They enable designers to enhance efficiency, as well as increase power density by using fewer parallel components, in converters for high-power equipment such as telecom and data-center servers powered from high bus voltages, industrial welders, plasma generators, high-frequency induction heaters, and X-ray machines.

With the fast-recovery body diode, the new devices enable higher efficiency in ZVS LLC resonant converters, which are chosen for applications that require high efficiency over a wide input-voltage range. Other types of bridged converters, as well as boost DC/DC converters for battery charging, also benefit from the reduced losses and enhanced dynamic performance of these devices. Compared with currently available VHV fast-diode MOSFETs, the DK5 devices from ST combine the best reverse-recovery time (trr) and lowest MOSFET gate charge (Qg) and R_DS(ON), with the favorable output and input capacitances (C_oss, C_iss) of a super-junction device.

The DK5 family extends ST’s VHV super-junction portfolio, which includes devices from 800V to 1500V, adding six new parts in TO-247, TO-247 Long-Lead, Max247, and ISOTOP power packages. Volume production has already started for the STWA40N95DK5, STY50N105DK5, and STW40N95DK5, with prices starting from $8.85 for orders of 1000 pieces.