features
  internal avalanche rugged 700v sensefet
  consumes only 0.8w at 230 vac & 0.5w load with
burst-mode operation
  precision fixed operating frequency, 100khz
  internal start-up circuit and built-in soft-start
  pulse-by-pulse current limiting and auto-restart
mode
  over-voltage protection (ovp), overload protection
(olp), internal thermal shutdown function (tsd)
  under-voltage lockout (uvlo)
  low operating current (3ma)
  adjustable peak current limit
applications
  auxiliary power supply for pc and server
  smps for vcr, svr, stb, dvd & dvcd player,
printer, facsimile & scanner
  adapter for camcorder
related application notes
  an-4134: design guidelines for off-line forward
converters using fairchild power switch (fps™)
  an-4137: design guidelines for off-line flyback
converters using fairchild power switch (fps™)
  an-4141: troubleshooting and design tips for
fairchild power switch (fps™) flyback applications
  an-4147: design guidelines for rcd snubber of
flyback
  an-4148: audible noise reduction techniques for
fps™ applications
description
the fsq0170rna, fsq0270rna, fsq0370rna
consists of an integrated current mode pulse width
modulator (pwm) and an avalanche-rugged 700v sense
fet. it is specifically designed for high-performance offline
switch mode power supplies (smps) with minimal
external components. the integrated pwm controller
features include: a fixed-frequency generating oscillator,
under-voltage lockout (uvlo) protection, leading
edge blanking (leb), an optimized gate turn-on/ turn-off
driver, thermal shutdown (tsd) protection, and
temperature compensated precision current sources for
loop compensation and fault protection circuitry.
compared to a discrete mosfet and controller or rcc
switching converter solution, the fsq0170rna,
fsq0270rna, fsq0370rna reduces total component
count, design size, and weight while increasing
efficiency, productivity, and system reliability. these
devices provide a basic platform that is well suited for the
design of cost-effective flyback converters, as in pc
auxiliary power supplies.
ordering information
8-dip
product number package marking code bvdss fosc rds(on) (max.)
fsq0170rna 8dip q0170r 700v 100khz 11ω
fsq0270rna 8dip q0270r 700v 100khz 7.2ω
fsq0370rna 8dip q0370r 700v 100khz 4.75ω