September 2002

1/15

VIPer12ADIP

VIPer12AS

LOW POWER OFF LINE SMPS PRIMARY SWITCHER

TYPICAL POWER CAPABILITY

FIXED 60 KHZ SWITCHING FREQUENCY

9V TO 38V WIDE RANGE V

VOLTAGE

CURRENT MODE CONTROL

AUXILIARY UNDERVOLTAGE LOCKOUT

WITH HYSTERESIS

HIGH VOLTAGE START UP CURRENT

SOURCE

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

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

13TR

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

REGULATOR

INTERNAL

SUPPLY

OVERVOLTAGE

LATCH

OVERTEMP.

DETECTOR

1 k

42V

230

VIPer12ADIP / VIPer12AS

2/15

PIN FUNCTION

CURRENT AND VOLTAGE CONVENTIONS

CONNECTION DIAGRAM

Name

Function

Power supply of the control circuits. Also provides a charging current during start up thanks to a high
voltage current source connected to the drain. For this purpose, an hysteresis comparator monitors the
V

voltage and provides two thresholds:

- V

DDon

: Voltage value (typically 14.5V) at which the device starts switching and turns off the start up

current source.
- V

DDoff

: Voltage value (typically 8V) at which the device stops switching and turns on the start up current

source.

SOURCE

Power MOSFET source and circuit ground reference.

DRAIN

Power MOSFET drain. Also used by the internal high voltage current source during start up phase for
charging the external V

capacitor.

Feedback input. The useful voltage range extends from 0V to 1V, and defines the peak drain MOSFET
current. The current limitation, which corresponds to the maximum drain current, is obtained for a FB pin
shorted to the SOURCE pin.

VDD

DRAIN

SOURCE

CONTROL

VIPer12A

DRAIN

VDD

SOURCE

VDD

SOURCE

SO-8

DIP8

VIPer12ADIP / VIPer12AS

3/15

ABSOLUTE MAXIMUM RATINGS

Note: 1. This parameter applies when the start up current source is off. This is the case when the V

voltage has reached V

DDon

and

remains above V

DDoff

2. This parameter applies when the start up current source is on. This is the case when the V

voltage has not yet reached V

DDon

or has fallen below V

DDoff

THERMAL DATA

Note: 1. When mounted on a standard single-sided FR4 board with 200 mm² of Cu (at least 35

m thick) connected to all DRAIN pins.

ELECTRICAL CHARACTERISTICS (T

=25°C, V

=18V, unless otherwise specified)

POWER SECTION

Note: 1. On clamped inductive load

Symbol

Parameter

Value

Unit

DS(sw)

Switching Drain Source Voltage (T

=25 ... 125°C)

(See note 1)

-0.3 ... 730

DS(st)

Start Up Drain Source Voltage (T

=25 ... 125°C)

(See note 2)

-0.3 ... 400

Continuous Drain Current

Internally limited

Supply Voltage

0 ... 50

Feedback Current

ESD

Electrostatic Discharge:
Machine Model (R=0

; C=200pF)

Charged Device Model

200

1.5

Junction Operating Temperature

Internally limited

Case Operating Temperature

-40 to 150

stg

Storage Temperature

-55 to 150

Symbol

Parameter

Max Value

Unit

Rthj-case

Thermal Resistance Junction-Pins for:
SO-8
DIP8

25
15

°C/W

Rthj-amb

Thermal Resistance Junction-Ambient for:
SO-8

(See note 1)

DIP8

(See note 1)

55
45

°C/W

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

DSS

Drain-Source Voltage

=1mA; V

=2V

730

DSS

Off State Drain Current

=500V; V

=2V; T

=125°C

0.1

DSon

Static Drain-Source
On State Resistance

=0.2A

=0.2A; T

=100°C

30
54

Fall Time

=0.1A; V

=300V

(See fig.1)

(See note 1)

100

Rise Time

=0.2A; V

=300V

(See fig.1)

(See note 1)

oss

Drain Capacitance

=25V

VIPer12ADIP / VIPer12AS

4/15

ELECTRICAL CHARACTERISTICS (T

=25°C, V

=18V, unless otherwise specified)

SUPPLY SECTION

Note: 1. These test conditions obtained with a resistive load are leading to the maximum conduction time of the device.

OSCILLATOR SECTION

PWM COMPARATOR SECTION

OVERTEMPERATURE SECTION

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

DDch

Start Up Charging
Current

=100V; V

=5V ...V

DDon

(See fig. 2)

-1

DDoff

Start Up Charging
Current
in Thermal Shutdown

=5V; V

=100V

> T

- T

HYST

DD0

Operating Supply Current
Not Switching

=2mA

DD1

Operating Supply Current
Switching

=0.5mA; I

=50mA

(Note 1)

4.5

RST

Restart Duty Cycle

(See fig. 3)

DDoff

Undervoltage

Shutdown Threshold

(See fig. 2 & 3)

DDon

Start Up Threshold

(See fig. 2 & 3)

14.5

DDhyst

Threshold

Hysteresis

(See fig. 2)

5.8

6.5

7.2

DDovp

Overvoltage

Threshold

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

OSC

Oscillator Frequency
Total Variation

DDoff

... 35V; T

=0 ... 100°C

kHz

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

to I

Current Gain

(See fig. 4)

320

Dlim

Peak Current Limitation

=0V

(See fig. 4)

0.32

0.4

0.48

FBsd

Shutdown Current

(See fig. 4)

0.9

FB Pin Input Impedance

=0mA

(See fig. 4)

1.2

Current Sense Delay to
Turn-Off

=0.2A

200

Blanking Time

500

ONmin

Minimum Turn On Time

700

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

Thermal Shutdown
Temperature

(See fig. 5)

140

170

°C

HYST

Thermal Shutdown
Hysteresis

(See fig. 5)

°C

VIPer12ADIP / VIPer12AS

8/15

Figure 8 : Rectangular U-I output characteristics for battery charger

RECTANGULAR U-I OUTPUT
CHARACTERISTIC
A complete regulation scheme can achieve
combined and accurate output characteristics.
Figure 8 presents a secondary feedback through
an optocoupler driven by a TSM101. This device
offers two operational amplifiers and a voltage
reference, thus allowing the regulation of both
output voltage and current. An integrated OR
function performs the combination of the two
resulting error signals, leading to a dual voltage
and current limitation, known as a rectangular
output characteristic.
This type of power supply is especially useful for
battery chargers where the output is mainly used in
current mode, in order to deliver a defined charging
rate. The accurate voltage regulation is also
convenient for Li-ion batteries which require both
modes of operation.

WIDE RANGE OF V

VOLTAGE

The V

pin voltage range extends from 9V to 38V.

This feature offers a great flexibility in design to
achieve various behaviors. In figure 8 a forward
configuration has been chosen to supply the
device with two benefits:
as soon as the device starts switching, it

immediately receives some energy from the
auxiliary winding. C5 can be therefore reduced
and a small ceramic chip (100 nF) is sufficient to
insure the filtering function. The total start up
time from the switch on of input voltage to output
voltage presence is dramatically decreased.

the output current characteristic can be

maintained even with very low or zero output
voltage. Since the TSM101 is also supplied in
forward mode, it keeps the current regulation up
whatever the output voltage is.The V

voltage may vary as much as the input voltage,
that is to say with a ratio of about 4 for a wide
range application.

C10

Vref

Vcc

GND

TSM101

R10

ISO1

VDD

DRAIN

SOURCE

CONTROL

VIPerX2A

AC IN

DCOUT

GND

VIPer12ADIP / VIPer12AS

9/15

FEEDBACK PIN PRINCIPLE OF OPERATION
A feedback pin controls the operation of the
device. Unlike conventional PWM control circuits
which use a voltage input (the inverted input of an
operational amplifier), the FB pin is sensitive to
current. Figure 9 presents the internal current
mode structure.
The Power MOSFET delivers a sense current I

which is proportional to the main current Id. R2
receives this current and the current coming from
the FB pin. The voltage across R2 is then
compared to a fixed reference voltage of about
0.23 V. The MOSFET is switched off when the
following equation is reached:

By extracting I

Using the current sense ratio of the MOSFET G

The current limitation is obtained with the FB pin
shorted to ground (V

= 0 V). This leads to a

negative current sourced by this pin, and
expressed by:

By reporting this expression in the previous one, it
is possible to obtain the drain current limitation
I

Dlim

In a real application, the FB pin is driven with an
optocoupler as shown on figure 9 which acts as a
pull up. So, it is not possible to really short this pin
to ground and the above drain current value is not
achievable. Nevertheless, the capacitor C is
averaging the voltage on the FB pin, and when the
optocoupler is off (start up or short circuit), it can be
assumed that the corresponding voltage is very
close to 0 V.
For low drain currents, the formula (1) is valid as
long as IFB satisfies I

< I

FBsd

, where I

FBsd

is an

internal threshold of the VIPer12A. If I

exceeds

this threshold the device will stop switching. This is
represented on figure 4, and I

FBsd

value is

specified in the PWM COMPARATOR SECTION.
Actually, as soon as the drain current is about 12%
of Idlim, that is to say 50 mA, the device will enter
a burst mode operation by missing switching
cycles. This is especially important when the
converter is lightly loaded.
It is then possible to build the total DC transfer
function between I

and I

as shown on figure 10.

This figure also takes into account the internal
blanking time and its associated minimum turn on
time. This imposes a minimum drain current under
which the device is no more able to control it in a
linear way. This drain current depends on the
primary inductance value of the transformer and
the input voltage. Two cases may occur,
depending on the value of this current versus the
fixed 50 mA value, as described above.

START UP SEQUENCE
This device includes a high voltage start up current
source connected on the drain of the device. As
soon as a voltage is applied on the input of the
converter, this start up current source is activated
as long as V

is lower than V

DDon

. When

reaching V

DDon

, the start up current source is

switched off and the device begins to operate by
turning on and off its main power MOSFET. As the
FB pin does not receive any current from the
optocoupler, the device operates at full current
capacity and the output voltage rises until reaching

Figure 9 : Internal Current Control Structure

60kHz

OSCILLATOR

PWM

LATCH

0.23V

DRAIN

SOURCE

+Vdd

Secondary
feedback

1 k

230

(

)

0.23V

--------------

I D

0.23V

--------------

0.23V

--------------

Dl im

0.23V

------

Figure 10 : I

Transfer function

FBsd

Dlim

ONmin

---------------------------------------

ONmin

---------------------------------------

50mA

Dpeak

Part masked by the

FBsd

threshold

VIPer12ADIP / VIPer12AS

10/15

the regulation point where the secondary loop
begins to send a current in the optocoupler. At this
point, the converter enters a regulated operation
where the FB pin receives the amount of current
needed to deliver the right power on secondary
side.
This sequence is shown in figure 11. Note that
during the real starting phase t

, the device

consumes some energy from the V

capacitor,

waiting for the auxiliary winding to provide a
continuous supply. If the value of this capacitor is
too low, the start up phase is terminated before
receiving any energy from the auxiliary winding
and the converter never starts up. This is illustrated
also in the same figure in dashed lines.

OVERVOLTAGE THRESHOLD
An overvoltage detector on the V

pin allows the

VIPer12A to reset itself when V

exceeds

DDovp

. This is illustrated in figure 12, which shows

the whole sequence of an overvoltage event. Note
that this event is only latched for the time needed
by V

to reach V

DDoff

, and then the device

resumes normal operation automatically.

Figure 11 : Start Up Sequence

DDon

OUT

DDoff

tss

Figure 12 : Overvoltage Sequence

DDon

DDoff

DDovp

VIPer12ADIP / VIPer12AS

13/15

SO-8

TUBE SHIPMENT (no suffix)

All dimensions are in mm.

Base Q.ty

100

Bulk Q.ty

2000

Tube length (± 0.5)

532

3.2

C (± 0.1)

0.6

TAPE AND REEL SHIPMENT (suffix "13TR")

All dimensions are in mm.

Base Q.ty

2500

Bulk Q.ty

2500

A (max)

330

B (min)

1.5

C (± 0.2)

20.2

G (+ 2 / -0)

12.4

N (min)

T (max)

18.4

TAPE DIMENSIONS

According to Electronic Industries Association
(EIA) Standard 481 rev. A, Feb 1986

All dimensions are in mm.

Tape width

Tape Hole Spacing

P0 (± 0.1)

Component Spacing

Hole Diameter

D (± 0.1/-0)

1.5

Hole Diameter

D1 (min)

1.5

Hole Position

F (± 0.05)

5.5

Compartment Depth

K (max)

4.5

Hole Spacing

P1 (± 0.1)

Top

cover

tape

End

Start

No components

Components

500mm min

Empty components pockets
saled with cover tape.

User direction of feed

REEL DIMENSIONS

VIPer12ADIP / VIPer12AS

15/15

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may results from its use. No license is
granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are
subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.

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