AN-8230 Datasheet, PDF (1/6 Pages) Fairchild Semiconductor – 800 V SuperFET® II MOSFET Cuts Switching Loss

www.fairchildsemi.com
AN-8230
800 V SuperFET^® II MOSFET Cuts Switching Loss for High
System Efficiency with Reliability
Abstract
Fairchild’s 800 V SuperFET^® II MOSFET family using the
latest super junction technology provides extremely low
conduction, switching loss and reliability; thanks to the
lowest R_DS(ON), stored energy in output capacitance (E_OSS)
and best-in-class robust body diode performance for
lighting, PC power, adapter, audio power, solar inverter,
industrial 3-phase topologies and auxiliary power supplies.
Utilizing an advanced charge balance technology, Fairchild
Semiconductor helps designers to achieve excellent system
efficiency and thermal characteristics with the 800 V
SuperFET^® II MOSFET family. Coupled with its best-in-
class reliability makes it ideal for a variety of applications,
while its broad range of package options give designers
tremendous flexibility, particularly with size constrained
designs.
Introduction
With lighting devices consuming around 19% of the world’s
total electrical power, many countries are phasing out the
sale of inefficient incandescent lamps as part of their energy
conservation efforts. According to industry reports, over
8000 billion incandescent lamps were sold in 2012, which
amounts to about 45% of total lighting sales. The United
States, China, Russia, and Brazil started banning sales of
incandescent light bulbs up to 60 W in 2014, putting the
conversion of residential indoor lighting from incandescent
to LED well on track. Meanwhile, advancements in LED
technology and improvements in production costs will most
certainly accelerate the growth of the LED lighting market.
Table 1 highlights the higher efficiency and longer lifetime
benefits of LED lighting over incandescent lamps.
Table 1. Efficiency and Lifetime Comparison
Important Facts
Incandescent
Lamp
LED
Lighting
Efficiency
6~16 lm/W
80~160 lm/W
Average Lifetime
1,200 hours
50,000 hours
The development of LED lighting power supply system
focuses on higher efficiency, dimming control and lower
cost. Furthermore, smart-phones are rapidly developing to
support multiple functions and features. It combines the
functionality of a pocket-sized communication device with
PC-like capabilities. As this happens, it requires more chips
and more processing cycles, which mean higher power
levels. Because of these additional functions, smart-phones
require much higher power than before. The conventional
linear battery charger no longer adequately meets charge
requirements due to its high-power dissipation. Therefore,
the key design challenge for battery charger of portable
devices such as smart-phones or tablet PCs is high power
density and high efficiency to meet energy regulation shown
in Table 2 [1].
Table 2. Energy-Efficiency Criteria for AC-AC and
AC-DC External Power Supplies in Active Mode:
Low Voltage Models
Nameplate Output _{Minimum Average Efficiency}
Power (P )
no
in Active Mode
0 to ≤ 1 W
≥ 0.497 * P + 0.071
no
> 1 to ≤ 49 W
≥ [0.075 * Ln (P )] + 0.569
no
> 49 W
≥ 0.860
Flyback converters are very popular for low power
applications such as LED lighting, battery charger or
adaptor because of its simplicity and low cost [2]. In order
to increase system efficiency, switching losses on the
primary-side have to be reduced. Low stored energy in
output capacitance; E_OSS and low R_DS(ON) of the MOSFET
are critical factor for flyback converters to maximize system
efficiency. New 800 V, SuperFET^® II MOSFET which is
optimized for primary switch, enables lower switching
losses and case temperature without sacrificing EMI
performance due to its optimized design.
© 2016 Fairchild Semiconductor Corporation
Rev. 1.0 • 8/8/16
www.fairchildsemi.com