st進口，原裝現貨，日期最新september 2002 1/15
viper12adip
viper12as
low power off line smps primary switcher
?
typical power capability
c110 fixed 60 khz switching frequency
c110 9v to 38v wide range v
dd
voltage
c110 current mode control
c110 auxiliary undervoltage lockout
with hysteresis
c110 high voltage start up current
source
c110 overtemperature, overcurrent and
overvoltage protection with
autorestart
description
the viper12a combines a dedicated current mode
pwm controller with a high voltage power
mosfet on the same silicon chip. typical
applications cover off line power supplies for
battery charger adapters, standby power supplies
for tv or monitors, auxiliary supplies for motor
control, etc. the internal control circuit offers the
following benefits:
– large input voltage range on the v
dd
pin
accommodates changes in auxiliary supply
voltage. this feature is well adapted to battery
charger adapter configurations.
– automatic burst mode in low load condition.
– overvoltage protection in hiccup mode.
mains type so-8 dip8
european
(195 - 265 vac)
8 w 13 w
us / wide range
(85 - 265 vac)
5 w 8 w
order codes
package tube t&r
so-8 viper12as viper12as13tr
dip-8 viper12adip
so-8 dip-8
block diagram
on/off
0.23 v
drain
source
vdd
pwm
latch
60khz
oscillator
blanking
+
_
8/14.5v
_
+
ff
s
r1
r4
q
r3
fb
regulator
internal
supply
overvoltage
latch
overtemp.
detector
1 k?
42v
_
+
r2
ff
s
r
q
230 ?