Fairchild Semiconductor’s Dual Switch Flyback Solution Provides Competitive Alternative to LLC, Single QR Flyback Topologies
August 01 2011 - 11:00AM
Business Wire
Designers of power supplies for All-In-One(AIO) applications are
faced with the challenges of limited space, the need to meet
worldwide energy regulations, as well as a solution that provides
ease of design.
In order to meet these challenges, Fairchild Semiconductor
(NYSE: FCS), a leading global supplier of high performance power
and mobile products, offers a dual switch flyback solution
incorporating mWSaver™ technology.
Traditional power topology solutions for AIO applications
include LLC and single switch Quasi-resonant (QR) flyback. When
balancing ease of design, power loss at different loading, and
efficiency, each of these topologies has advantages and
disadvantages. For AIO power range, LLC offers the best overall
efficiency, compared to dual switch QR and single switch QR flyback
converters. The LLC transformer is difficult to design and results
in the highest light load power loss among the three topologies.
Single switch QR flyback converters are the least efficient, but
they are easy to design and offer low power loss at light load.
Fairchild’s dual switch QR flyback topology and secondary
synchronous rectification is the ideal solution for AIO
applications - providing good overall efficiency, managing low
power loss at light load, while providing ease of design.
The AIO solution from Fairchild is perfectly suited for
applications from 75W~230W and consists of the FAN6920MR integrated
critical mode PFC and Quasi-resonant Current Mode PWM controller,
the FAN7382 gate driver, in tandem with the FAN6204 secondary
synchronous rectifier controller for flyback topology and forward
freewheeling rectification. Combined, these devices provide
best-in-class power consumption at no/light load, enabling designs
to meet 2013 ErP standard without the additional circuitry LLC
solutions require.
Incorporating mWSaver™ technology, these devices additionally
offer the lowest standby power input for AIO solutions.
Quasi-resonant control reduces snubber and leakage inductance
losses, while improving thermal issues. It also lowers the Vds of
the SR MOSFET to provide improved efficiency, and allows for
smaller board size. Built-in two-level PFC output improves low line
efficiency.
Adding the FAN7382, a high and low side gate drive IC, rounds
out Fairchild’s solution by providing the ability to drive
Fairchild’s High Voltage MOSFETs up to 600V. This device provides
stable operation of the high-side driver under high-dv/dt noise
circumstances.
The FAN6920MR combines a power factor correction (PFC)
controller and a quasi-resonant PWM controller for a cost effective
design that uses fewer external components. For PFC, the device
uses a controlled on-time technique to provide a regulated DC
output voltage and to perform natural power factor correction. With
an innovative total harmonic distortion (THD) optimizer, the
FAN6920MR can reduce input current distortion at zero-crossing
duration in order to improve THD performance. For PWM control, the
FAN6920MR provides several functions to enhance the power system
performance, including extended valley detect up to the 12th valley
cycle for reduced switching frequency, improved light load
efficiency, green-mode operation, an internal 10ms soft start, and
high/low line over-power compensation.
Using a proprietary linear prediction timing-control technique,
not limited to the RDS(ON) of the external Fairchild power-trench
SR MOSFET, the FAN6204 is suitable for fixed frequency or
quasi-resonant (QR) flyback converters operating in discontinuous
or continuous conduction mode (DCM and CCM) control. This technique
includes a simple control method without current-sense circuitry,
which provides better noise immunity. With PWM frequency tracking
and secondary-side winding voltage detection, the device can
operate in both fixed-and variable-frequency systems, making it
adaptable to flyback and forward free-wheeling topologies. The
FAN6204 also features an ultra-low green mode operating current
(1.1mA typical). This internal green mode provides lower no-load
power consumption and higher light-load efficiency.
The FAN7382 can drive Fairchild’s super-junction SupreMOS® and
SuperFET® MOSFETs. Fairchild's high-voltage (up to 600V) process
and common-mode noise canceling technique provides stable operation
under high dv/dt noise circumstances. An advanced level shift
circuit allows high-side gate driver operation up to VS = -9.8 V
(typ.) for VBS = 15V. The input logic level is compatible with
standard TTL-series logic gates. UVLO circuits for both channels
prevent malfunction when VCC and VBS are lower than the specified
threshold voltage.
Fairchild Semiconductor enables engineers to drive innovation in
their designs by offering smaller size and increased performance
through advanced silicon and package options. These dual flyback
solutions for AIO PC applications featuring mWSaver™ technology
allow designers to meet today’s stringent demands for power savings
and performance.
Fairchild Semiconductor: Solutions for Your Success™
Price: in 1,000 quantity pieces
FAN6920MR
US $1.20
FAN6204
US $0.57
FAN7382
US $0.83
Availability: Samples available now
Delivery: 8-10 weeks ARO
Contact Information:
To contact Fairchild Semiconductor about this product, please go
to: http://www.fairchildsemi.com/cf/sales_contacts/.
For information on other products, design tools and sales
contacts, please visit: http://www.fairchildsemi.com.
Note to Editor: For a datasheet in PDF format, please go
to:
http://www.fairchildsemi.com/ds/FA/FAN6920MR.pdf
http://www.fairchildsemi.com/ds/FA/FAN6204.pdf
http://www.fairchildsemi.com/ds/FA/FAN7382.pdf
About Fairchild Semiconductor:
Fairchild Semiconductor (NYSE: FCS) – global presence, local
support, smart ideas. Fairchild delivers energy-efficient,
easy-to-use and value-added semiconductor solutions for power and
mobile designs. We help our customers differentiate their products
and solve difficult technical challenges with our expertise in
power and signal path products. Please contact us on the web at
www.fairchildsemi.com.
Follow us on Twitter @ http://twitter.com/FairchildSemi
View product and company videos, listen to podcasts and comment
on our blog @
http://www.fairchildsemi.com/engineeringconnections
Visit us on Facebook @
http://www.facebook.com/FairchildSemiconductor
Fairchild Semiconductor (NASDAQ:FCS)
Historical Stock Chart
From May 2024 to Jun 2024
Fairchild Semiconductor (NASDAQ:FCS)
Historical Stock Chart
From Jun 2023 to Jun 2024