Document
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 undervoltage lockout with hysteresis ■ High voltage start-up current source ■ Overtemperature, overcurrent and overvoltage
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 overvoltage 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
OVERVOLTAGE
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3
Pin connections and function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4
Rectangular U-I output characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5
Wide range of VDD voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6
Feedback pin principle of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7
Startup sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8
Overvoltage threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
9
Operation pictures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
10
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
11
Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
12
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
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Doc ID 11977 Rev 2
VIPER12A-E
1
Electrical data
Electrical data
1.1 1.2
Maximum rating
Stressing the device above the rating listed in the “absolute maximum ratings” table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Table 1. Absolute maximum rating
Symbol
Parameter
Value
Unit
VDS(sw) VDS(st)
ID VDD IFB
VESD
Switching drain source voltage (TJ = 25 ... 125 °C) (1) Start-up drain source voltage (TJ = 25 ... 125 °C) (2) Continuous drain current
Supply voltage
Feedback current
Electrostatic discharge: Machine model (R = 0 Ω; C = 200 pF) Charged device model
-0.3 ... 730
V
-0.3 ... 400
V
Internally limited
A
0 ... 50
V
3
mA
200
V
1.5
kV
TJ Junction operating temperature
Internally limited
°C
TC Case operating temperature
-40 to 150
°C
Tstg Storage temperature
-55 to 150
°C
1. This parameter applies when the start-up current source is OFF. This is the case when the VDD voltage has reached VDDon and remains above VDDoff.
2. This parameter applies when the start up current source is ON. This is the case when the VDD voltage has not yet reached VDDon or has fallen below VDDoff.
Thermal data
Table 2. Thermal data
Symbol
Parameter
SO-8
DIP-8
Unit
RthJC Thermal resistance junction-case
Max
25
15
°C/W
RthJA Thermal resistance ambient-case (1)
Max
55
45
°C/W
1. When mounted on a standard single-sided FR4 board with 200 mm2 of Cu (at least 35 µm thick) connected to all DRAIN pins.
Doc ID 11977 Rev 2
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Electrical characteristics
2
Electrical characteristics
VIPER12A-E
TJ = 25 °C, VDD = 18 V, unless otherwise specified
Table 3. Power section
Symbol
Parameter
Test conditions
Min Typ Max Unit
BVDSS Drain-source voltage ID = 1 mA; VFB = 2 V
730
V
IDSS
OFF State drain current
VDS .