ST takes super-junction power MOSFETs to 1500V rating

October 21, 2015 // By Graham Prophet
A family of power MOSFETs from STMicroelectronics allows designers of power supplies to maximise power efficiency while enhancing robustness and safety margins. The MDmesh K5 devices are the first to combine the benefits of super-junction technology with a drain-to-source breakdown voltage of 1500V.

A target market is higher output power auxiliary switched-mode power supplies in servers, where power-supply robustness is a key factor in minimising down-time, and in industrial applications such as welding and factory automation. For these applications, where power output ranges from 75W to 230W or above, super-junction MOSFET technology is the preferred choice because of its outstanding dynamic-switching performance.

MDmesh K5 Power MOSFETs claim the lowest on-resistance (Rds(on)) per area and the lowest gate charge (Qg), resulting in the industry's best FoM (Figure of Merit). The devices can be used in all popular power-supply topologies, including standard, quasi-resonant and active-clamp flyback converters, and LLC half bridge converters for applications where high efficiency (up to 96%) and output powers approaching 200W are required for a wide range of input voltages.

The first two members of the new family are the STW12N150K5 and the STW21N150K5, which offer maximum drain-to-source currents of 7A and 14A, respectively, with gate charge as low as 47 nC (STW12N150K5) or on-resistance as low as 0.9Ω (STW21N150K5). Both devices come in TO-247 packages in volume quantities at prices of $14 (1,000).