900V MOSFETs boost efficiency of flyback converters

March 09, 2017 // By Nick Flaherty
STMicroelectronics has launched new versions of its 900V super-junction MOSFETs with best-in-class on-resistance (RDSON) and dynamic characteristics.

A 900V breakdown voltage assures extra safety margin in systems with high bus voltages. The 900V MDmesh K5 super-junction MOSFETs contain the first 900V MOSFETs with RDS ON below 100mΩ, the industry’s best value among DPAK devices. With a low gate charge (Qg), the devices ensure faster switching for greater flexibility where a wide input-voltage range is required. These characteristics ensure high efficiency and reliability in all types of flyback converters including standard, quasi-resonant, and active-clamp designs covering power ratings as low as 35W up to 230W or higher. In addition, low input and output capacitances (Ciss, Coss) enable zero-voltage switching with minimal energy loss in half-bridge LLC resonant converters.

The increased safety margin and superior static and dynamic behavior of the new devices enable designers to improve the performance of a wide variety of products such as server power supplies, 3-phase switched-mode power supplies (SMPS), LED lighting supplies, electric-vehicle (EV) chargers, solar generators, welders, industrial drives, and factory automation.

ST’s family of MDmesh K5 super-junction transistors now covers voltage ratings of 800V, 850V, 900V, 950V, 1050V, 1200V, and 1500V, together with package options including TO-220AB, TO-220FP, TO-247, TO-247 Long Lead, IPAK and I2PAK, as well as D2PAK and DPAK surface-mount power packages.

The 900V MOSFETs are priced from $0.73 for the STD4N90K5 in DPAK package’

For further information please visit  www.st.com/mdmeshk5.