VIPER12A-E
Low power offline switched-mode power supply primary switcher
Features
■ Fixed 60 kHz switching frequency ■ ...
VIPER12A-E
Low power offline switched-mode power supply primary switcher
Features
■ Fixed 60 kHz switching frequency ■ 9 V to 38 V wide range VDD
voltage ■ Current mode control ■ Auxiliary under
voltage lockout with hysteresis ■ High
voltage start-up current source ■ Overtemperature, overcurrent and over
voltage
protection with auto-restart ■ Typical power capability
– European (195 - 265 Vac) 8 W for SO-8, 13 W for DIP-8
– European (85 - 265 Vac) 5 W for SO-8, 8 W for DIP-8
Description
The VIPER12A combines a dedicated current mode PWM controller with a high
voltage power
MOSFET on the same silicon chip.
Figure 1. Block diagram
SO-8
DIP-8
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 VDD pin accommodates changes in auxiliary supply
voltage (This feature is well adapted to battery charger adapter configurations), automatic burst mode in low load condition and over
voltage protection in HICCUP mode.
DRAIN
REGULATOR
INTERNAL SUPPLY
VDD FB
_ 8/14.5V +
+ 42V _
ON/OFF
60kHz OSCILLATOR
OVERTEMP. DETECTOR
S R1 FF Q R2 R3 R4
PWM LATCH
OVER
VOLTAGE
R
LATCH
S FF Q
BLANKING
+ _ 0.23 V
1 kΩ
230 Ω SOURCE
December 2010
Doc ID 11977 Rev 2
1/21
www.st.com
21
Contents
Contents
VIPER12A-E
1
Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . ....