STMicroelectronics New Super-Junction Transistors Offer Best-In-Class Energy Efficiency

A new family of rugged, high-efficiency power products from STMicroelectronics, a global semiconductor leader serving customers across the spectrum of electronics applications, enables technology companies to satisfy stricter power and efficiency targets set by eco-design standards and to target green-energy applications such as solar micro-inverters, photovoltaic string inverters and electric vehicles.

The new devices include the industry's first super-junction transistors (MOSFETs) capable of withstanding peak voltages up to 950V, as well as 900V devices offering best-in-class energy efficiency and the world's only 850V devices to be offered in the ultra thin and space-saving PowerFLAT 8x8 HV package. Super-junction technology enables MOSFETs to achieve higher operating voltages with very low electrical on-resistance in relation to device size, enabling power supplies to deliver increased system reliability and energy efficiency within compact overall dimensions.

ST is a major supplier of super-junction MOSFETs, and now offers the highest voltage rating in the market as well as the industry's only second source of 900V super-junction devices. In addition, the family will soon be extended to include new 800V devices.

Super-junction technology for a greener world:

Demonstrating the efficiency of the SuperMESH 5 devices, ST also revealed details of the first successful customer application for its ultra high-voltage MOSFETs. TCI (www.tcisaronno.net), an Italian solid-state lighting innovator, has chosen the 950V STU6N95K5 in IPAK package as the main power switch in its latest LED drivers for advanced and feature-rich LED lamps offering benchmark energy efficiency in a physically compact and cost-effective form factor. STs latest-generation SuperMESH 5 technology enabled TCI to establish the best efficiency and safety margin in the marketplace, creating a compelling value proposition for its customers, said Maurizio Giudice, Power Transistor Division Marketing Director for ST.

Other popular high-volume applications for STs new super-junction MOSFETs include flat-panel televisions, PC power supplies, LED lighting drivers, and electronic ballasts for High-Intensity Discharge (HID) lamps. The MOSFETs will enable designers to meet increasingly strict limits on maximum power and minimum energy efficiency specified by eco-design standards such as Energy Star and the EU's Energy-related Products (ErP) Directive.

An example of tougher eco-design regulation can be seen in the latest Energy Star Program Requirements for Televisions, version 5.3, which specifies an absolute maximum power limit of 108.0 Watts for 50-in. or larger flat-screen televisions. Another can be found in the ErP lighting regulations, which demand increases in the minimum efficacy of various types of HID lamps between 2012 and 2017.

The high voltage rating of STs new super-junction MOSFETs increases system safety and reliability. This is an important benefit in HID lamp ballasts and other systems operating at AC line voltages and higher, such as solar micro-inverters and charging points for electric vehicles. Charging points require very high power-conversion efficiency both to minimize charge time and vehicle running costs. In dc-to-ac inverters for solar micro-generators, high-efficiency, high-voltage MOSFETs enable designers to use higher switching frequencies and so generate high-quality ac power while reducing energy losses and solution size.

Key features of SuperMESH 5 MOSFETs:

The new MOSFETs are the first in STs SuperMESH 5 fifth-generation super-junction family. They include the 900V STx21N90K5, 950V STx20N95K5 and 950V STx6N95K5 in various package options. The STL23N85K5 850V variant in the PowerFLAT 8x8 HV high-voltage surface-mount package has a footprint of 64mm², which is 56% smaller than the industry-standard D²PAK package. In addition, its mounted height of 1mm is 77% lower than D²PAK allowing use in ultra-slim designs.

For the 900V STP21N90K5, the Figure of Merit (FOM), which indicates the device's overall energy efficiency when turned on as well as when switching on or off, is 62.5% better than the only comparable alternative device in the market. This enables designers to achieve an appreciable efficiency increase simply by using the STP21N90K5 rather than the competing device.

The new SuperMESH 5 devices are available immediately for sample or production orders, priced from $3.50 to $10.00 in quantities of 1,000 units depending on voltage/current rating and package type. Alternative pricing options for larger orders are available on request. For further information please visit www.st.com/pmos.