Datasheet VIPER20SP, VIPER20DIP, VIPER20ASP, VIPER20ADIP, VIPER20A Datasheet (SGS Thomson Microelectronics)

VIPer20/SP/DIP



TYPE V

DSS

I

R

n

DS(on)

VI Per 2 0/ SP/DI P 620V 0.5 A 16 Ω
VIPer20A/A SP/ AD IP 700V 0.5 A 18 Ω

FEATURE

■ ADJUSTABLESWITCHINGFREQUENCYUP

TO200KHZ

■ CURRENT MODE CONTROL

■ SOFTSTART AND SHUT DOWN CONTROL

■ AUTOMATIC BURST MODE OPERATION IN

STAND-BY CONDITIONABLE TO MEET
”BLUE ANGEL” NORM (<1W TOTAL POWER
CONSUMPTION)

■ INTERNALLY TRIMMEDZENER

REFERENCE

■ UNDERVOLTAGE LOCK-OUT WITH

HYSTERESIS

■ INTEGRATED START-UPSUPPLY

■ AVALANCHERUGGED

■ OVERTEMPERATURE PROTECTION

■ LOW STAND-BYCURRENT

■ ADJUSTABLECURRENTLIMITATION

DESCRIPTION

VIPer20/20A, made using VIPower M0

VIPer20A/ASP/ADIP

SMPS PRIMARY I.C.

PENTAWATTHV

10

1

PowerSO-10

Technology, combines on the same silicon chip a
state-of-the-art PWM circuit together with an
optimized high voltage avalanche rugged Vertical
Power MOSFET (620Vor 700V / 0.5A).

Typical applications cover off line power supplies
with a secondary power capability of 10W in wide
range condition and 20W in single range or with
doubler configuration. It is compatible from both
primary or secondary regulation loop despite
using around 50% less components when
compared with a discrete solution. Burst mode
operation is an additional feature of this device,
offering the possibility to operate in stand-by
mode without extra components.

PENTAWATT HV (022Y)

DIP-8

BLOCK DIAGRAM

November 1999

VDD

13 V

_

+

ERROR

AMPLIFIER

UVLO

LOGIC

0.5V +

ON/OFF

_

4.5V

SECURITY

LATCH

R/SSQSR1

OVERTEMP.

DETECTOR

1.7

µ

s

delay

OSCILLATOR

PWM

LATCH

R2 R3

COMP

OSC

DRAIN

FFFF

Q

0.5V
_

+

+

250ns

Blanking

6 V/A

_

CURRENT

AMPLIFIER

FC00491

SOURCE

1/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

ABSOLUTEMAXIMUM RATING

Symb o l Para met er Val u e Uni t

V

I

V

V

OSC

V

COMP

I

COMP

V

I

D(AR)

P

T

T

THERMALDATA

R

thj-pin

R

thj-case

R

thj-a mb.

(*) When mounted using the minimum recommended pad size on FR-4 board.
# On multylayer PCB

Continuous Drain-Sour ce Voltage (Tj = 25 to 125oC)

DS

for VIPer20/ SP/DI P
for VIPer20A/ASP/ A DI P

Maximum Current Inte rnally Limited A

D

Supply Volt age 0 to 15 V

DD

Volt age Range Input 0 to V

-0.3 to 620

-0.3 to 700

DD

Volt age Range Input 0 to 5 V
Maximum Continuous Curre nt ±2mA
Elect r o st at ic discharge (R = 1. 5 K Ω C = 100pF)

esd

Avalanche Drain-Sour ce Curr e nt , Repetitive or Not-Repetit ive
(T C = 100

o

C, Pulse Width Limited by TJmax, δ <1%)
for VIPer20/ SP
for VIPer20A/ASP/ A DI P
Power Dissipation at Tc = 25oC57W

tot

Junction Operating Tempe r at ure Int ernally Limited

j

St orage T emperature -65 to 150

stg

4000 V

0.5

0.4

PENTAW ATT Po w erS O -10 DIP-8

20
Ther mal Res istance Junc ti on-case Max 2.0 2.0
Ther mal Res istance Ambient-case Max 70 60 35 #

o
o

o

C/W

o

C/W

o

C/W

V
V

V

A
A

C
C

CONNECTION DIAGRAMS(Top View)

PENTAWATT HV PENTAWATT HV (022Y) PowerSO-10 DIP-8

OS C

Vdd

SOURC E

COMP

CURRENT AND VOLTAGECONVENTIONS

IDD ID

OSC

I

OSC

DD

V

OSC

V

13V

­+

ICOMP

VCOMP

DRAINVDD

COMP SOURCE

VDS

FC00020

1

4

8

5

SC105 40

DRAIN

DRAIN

DRAIN

DRAIN

2/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

ORDERING NUMBERS

PENT AWATT HV PENT AWATT HV (022Y) Powe rSO-10 DIP -8

VIPer20

VIPer20A

VIP er 20 (022Y)

VIPer20A (0 22Y)

VIPer20SP

VIPer20ASP

VIPer20DIP

VIPer20ADIP

PINSFUNCTIONAL DESCRIPTION
DRAINPIN:

Integrated power MOSFET drain pin. It provides
internal bias current during start-up via an
integrated high voltage current source which is
switched off during normal operation.The device
is able to handle an unclampedcurrent during its
normal operation, assuring self protection against
voltage surges, PCB stray inductance, and
allowing a snubberless operation for low output
power.

SOURCEPIN:

Power MOSFET source pin. Primary side circuit
commonground connection.

VDD PIN :

This pin providestwo functions:

- It corresponds to the low voltage supply of the

controlpart of the circuit. If V
the start-up current source is activated and the
output power MOSFET is switched off until the
V

voltage reaches 11V. During this phase,

DD

the internal current consumption is reduced,
the V

pin is sourcing a currentof about 2mA

DD

and the COMP pin is shorted to ground. After
that, the current source is shut down, and the
devicetries to start upby switching again.

goes below 8V,

DD

- This pin is also connected to the error

amplifier, in order to allow primary as well as
secondary regulation configurations. In caseof
primary regulation, an internal 13V trimmed
reference voltage is used to maintain V
13V. For secondary regulation, a voltage
between 8.5V and 12.5V will be put on V
by transformer design, in order to stuck the
output of the transconductanceamplifier to the
high state. The COMP pin behaves as a

DD

DD

at

pin

constant current source, and can easily be
connected to the output of an optocoupler.
Note that any overvoltage due to regulation
loop failure is still detected by the error
amplifier through the V

voltage, which

DD

cannot overpass 13V. The output voltage will
be somewhathigher thanthe nominalone, but
still under control.

COMP PIN :

This pin provides two functions:

- It is the output of the error transconductance

amplifier, and allows for the connection of a
compensation network to provide the desired
transfer function of the regulation loop. Its
bandwidth can be easily adjusted to the
needed value with usual componentsvalue. As
stated above, secondary regulation
configurations are also implemented through
the COMPpin.

- When the COMP voltage is going below 0.5V,

the shut-downof the circuit occurs, with a zero
duty cycle for thepower MOSFET. This feature
can be used to switch off the converter, and is
automatically activated by the regulation loop
(whatever is the configuration) to provide a
burst mode operation in case of negligible
output power or openload condition.

OSC PIN :

An R
to define the switching frequency. Note that
despite the connection of R
significant frequency change occurs for V
varying from 8V to 15V. It provides also a
synchronisationcapability, when connected to an
external frequencysource.

network must be connectedon that pin

T-CT

to VDD,no

T

DD

3/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

AVALANCHE CHARACTERISTICS

Symb o l Para met er Max Valu e Uni t

I

D(ar)

E

ELECTRICAL CHARACTERISTICS (TJ=25oC, VDD=13 V, unless otherwisespecified)
POWERSECTION

Symb o l Parameter Test Con d it i ons Mi n . Typ . Ma x. Unit

BV

I

DSS

R

DS(on)

C

OSS

(1) On Inductive Load, Clamped.

Avalanche Current , Repetit ive or Not-Repet it ive
(pulse widt h limited by T
for VIPer20/ SP/DI P
for VIPer20A/ASPA/DIP (see fig. 12)

Single Pulse Avalanche Ener g y

(ar)

(starti ng T

Drain-Source Voltage ID=1mA V

DSS

=25oC, ID=I

j

Of f - State Drain Current V

max, δ <1%)

j

) (see fig.12)

D(ar)

COMP

for VIPer20/SP/D IP
for VIPer20A/ASP/ DIP (see fig.5)

=0V TJ=125oC

COMP

= 620 V

V

DS

0.5

0.4
10 mJ

=0V

620
700

for VIPer20/SP/D IP

= 700 V

V

DS

for VIPer20A/ASP/ ADIP

St at ic Drain Source on
Resistance

ID=0.4A
for VIPer20/SP/D IP
for VIPer20A/ASP/ ADIP

=0.4A TJ=100oC

I

D

13.5

15.5

for VIPer20/SP/D IP
for VIPer20A/ASP/ ADIP

t

Fall T ime ID = 0.2 A Vin=300V(1)

f

100 ns

(see fig. 3)

Rise Time ID=0.4A Vin= 300 V (1)

t

r

50 ns

(see fig. 3)

Out put Capacitance VDS=25V 90 pF

1.0

1.0

16
18

29
32

A
A

V
V

mA
mA

Ω
Ω

Ω
Ω

SUPPLY SECTION

Symb o l Parameter Test Con d it i ons Mi n . Typ . Ma x. Unit

4/21

I

DDch

I

DD0

I

DD1

I

DD2

V

DDo f f

V

DDo n

V

DDhyst

St art - u p Charging
Current

Oper at i ng Supply Current VDD=12V, FSW=0KHz

VDD=5V VDS=70V
(see fig. 2 and fig. 15)

-2 mA

12 16 mA

(see fig. 2)

Oper at i ng Supply Current VDD=12V, FSW=100KHz 13 mA
Oper at i ng Supply Current VDD=12V, FSW=200KHz 14 mA
Undervoltage Shutdown (see fig. 2) 7.5 8 V
Undervoltage Reset (see fig. 2) 11 12 V
Hysteresis Start-up (see fig. 2) 2.4 3 V

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

ELECTRICAL CHARACTERISTICS (continued)

OSCILLATORSECTION

Symb o l Parameter Test Con d it i ons Mi n . Typ . Ma x. Unit

F

V

OSCih

V

OSCil

ERRORAMPLIFIERSECTION

Symbol Parameter Test C ondition s Min. Typ . Max. Un it

V

DDreg

∆V

DDreg

G

A

VOL

G

V

COMPLO

V

COMPHI

I

COMPLO

I

COMPHI

Os cillator Frequency

SW

Total Variation

= 8.2 K

R

T

= 9 t o15 V

V

DD

with R

Ω

CT=2.4 nF

± 1% CT ± 5%

T

90 100 110 KHz

(see fig. 6 and fig. 9)

Os cillator Peak Voltage 7.1 V
Os cillator Valley V o lt age 3.7 V

VDD Regulat ion Point I

= 0 m A (see fig.1) 12.6 13 13. 4 V

COMP

Total Variation TJ= 0 to 100oC2%
Unity Gain Bandwidt h Fr om Input = VDDto Output = V

BW

COMP

150 KHz

COM P pin is open (see fig. 10 )

Open Loop V o lt age

COM P pin is open (see fig. 10 ) 45 52 dB

Gain
DC Transconduc tance V

m

Out put Low Level
Out put High L evel
Out put Low Current

= 2.5 V (see fig. 1) 1.1 1.5 1.9 mA/V

COMP

=-400µAVDD=14V

I

COMP

= 400 µ AVDD=12V

I

COMP

V

=2.5V VDD= 14 V -600 µ A

COMP

0.2 V

4.5 V

Capability
Out put High C urr ent

V

=2.5V VDD= 12 V 600 µA

COMP

Capability

PWM COMPARATORSECTION

Symbol Parameter Test C ondition s Min. Typ . Max. Un it

H

V

COMPoffVCOMP

I

Dpeak

t

∆V

ID

Peak Current Limitation VDD= 12 V COMP pin open 0.5 0.67 0.9 A
Current Sense Delay

d

/∆I

COMP

Dpeak

off s et I

V

= 1 to 3 V 4.2 6 7.8 V/A

COMP

=10mA 0.5 V

Dpeak

ID= 1 A 250 ns

to turn-off

t

t

on(min)

Blanking T ime 250 3 60 ns

b

Minimum on T ime 350 ns

SHUTDOWNAND OVERTEMPERATURESECTION

Symbol Parameter Test C ondition s Min. Typ . Max. Un it

V

COMPth

t

DISsu

T

T

hyst

Restart threshold (see fig. 4) 0.5 V
Disable Set Up Time (see f ig. 4 ) 1.7 5 µs
Ther mal Shut down

tsd

(see fig. 8 ) 140 170 190

Tem perature
Ther mal Shut down

(see fig. 8 ) 40

Hyst eresis

o

o

C

C

5/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

Figure1:VDDRegulationPoint

COMP

I

ICOMPHI

0

ICOMPLO

VDDreg

Figure3: TransitionTime

ID

10%Ipeak

Slope =

Gm in mA/V

FC00150

Figure2: UndervoltageLockout

IDD

IDD0

DD

V

VDDhyst

V

DDoff

IDDch

Figure4: ShutDown Action

VOSC

VCOMP

t

tDISsu

VDS=70V

Fsw = 0

V

DDon

FC00170

VDD

t

VDS

VCOMPth

90%VD

ID

10%V

D

t

tf tr

FC00160

ENABLE

DISABLE

Figure5: BreakdownVoltage vs Temperature Figure6: Typical FrequencyVariation

1.15

BV

DS S

(Nor malize d)

1.1

1.05

0.95

1

0 20406080100120

Temperature ( C)

FC00180

1

(%)

0

-1

-2

-3

-4

-5
0 20 40 60 80 100 120 140

Temperature ( C)

t

t

ENABLE

FC00060

FC00190

6/21

Figure7: Start-upWaveforms

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

Figure8: OvertemperatureProtection

Ttsd

Tts d-Thys t

Vddon
Vddoff

Tj

t

Vdd

t

Id

t

Vco mp

t

SC1 019 1

7/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

Figure9: Oscillator

Ct

Rt

OSC

~360Ω

VDD

Dmax

0.9

0.8

0.7

For RT> 1.2 KΩ:

SW

MAX

=

= 1 −

R

2.3

TCT

D

MAX

550

RT− 150

MAX

values:

F

CLK

D
RecommendedD

100KHz: > 80%
200KHz: > 70%

FC00050

Maximum duty cycle vs Rt

1

FC00040

Frequency (kHz)

0.6

0.5
1 2 3 5 10 20 30 50

Rt (kΩ)

Oscillatorfrequency vs Rtand Ct

1,000

Ct = 1.5 nF

500

Ct = 2.7nF

300

Ct = 4.7nF

200

Ct = 10nF

100

50

30

1 2 3 5 10 20 30 50

Rt (kΩ)

FC00030FC00030

8/21

Figure10: ErrorAmplifierFrequencyResponse

60

RCOMP= +∞
RCOMP= 270k

40

RCOMP= 82k

RCOMP= 27k

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

FC00200

20

VoltageGain (dB)

RCOMP= 12k

0

(20)

0.001 0.01 0.1 1 10 100 1,000

Figure11: ErrorAmplifierPhase Response

200

150

Frequency (kHz)

FC00210

RCOMP= +∞
RCOMP= 270k

RCOMP= 82k

RCOMP= 27k

Phase (°)

100

50

RCOMP= 12k

0

(50)

0.001 0.01 0.1 1 10 100 1,000

Frequency (kHz)

9/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

Figure12: AvalanceTest Circuit

L1
1mH

BT2
12V

C1
47uF
16V

1

U1
VIPer20

R2
1k

OSC

23

DRAINVDD

-

13V

+

COMP SOURCE

54

R3
100

Q1
2 x STHV102FIin parallel

R1

47

GENERATORINPUT

500us PULSE

FC00196

BT1
0 to 20V

10/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

Figure13: OffLine Power SupplyWith Auxliary Supply Feedback

F1

13V

BR1

­+

C2

D3

C4

COMP SOURCE

C11

D1

R1

C3

R7

DRAINVDD

VIPer20

C6

R3

AC IN

TR2

C1

R9

R2

OSC

C5

TR1

D2

C10

L2

C9C7

+Vcc

GND

FC00401

Figure14: OffLine Power SupplyWith OptocouplerFeedback

F1

13V

BR1

­+

C2

D3

C4

COMP SOURCE

C11

D1

R1

C3

R7

DRAINVDD

VIPer20

C6

R3

AC IN

TR2

C1

R9

R2

OSC

C5

TR1

D2

C10

R6

ISO1

U2

C8

L2

C9C7

R4

R5

+Vcc

GND

FC00411

11/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

OPERATIONDESCRIPTION:
CURRENT MODE TOPOLOGY:

The current mode control method, like the one
integrated in the VIPer20/20A uses two control
loops - an inner current control loop and an outer
loop for voltage control. When the Power
MOSFET output transistor is on, the inductor
current (primary side of the transformer) is
monitored with a SenseFET technique and
converted into a voltage V
current. When V

reaches V

S

proportional to this

S

(the amplified

COMP

output voltage error) the powerswitch is switched
off. Thus, the outer voltage control loop defines
the level at which the inner loop regulates peak
current through the powerswitch and the primary
windingof the transformer.

Excellent open loop D.C. and dynamic line
regulation is ensured due to the inherent input
voltage feedforward characteristic of the current
mode control. This results in an improved line
regulation, instantaneous correction to line
changes and better stability for the voltage
regulationloop.

Current mode topology also ensures good
limitation in the caseof short circuit. During a first
phase the output current increases slowly
followingthe dynamic of the regulationloop. Then
it reaches the maximum limitation current
internally set and finallystops because the power
supply on V

is no longer correct. For specific

DD

applications the maximum peak current internally
set can be overridden by externally limiting the
voltage excursion on the COMP pin. An
integrated blanking filter inhibits the PWM
comparator output for a short time after the
integrated Power MOSFET is switched on. This
function prevents anomalous or premature
termination of the switching pulse in the case of
current spikes caused by primary side
capacitance or secondary side rectifier reverse
recovery time.

STAND-BY MODE

Stand-by operation in nearly open load condition
automatically leads to a burst mode operation
allowing voltage regulation on the secondary
side. The transition from normal operation to
burst mode operation happens for a power P

STBY

given by :

1

2

P

STBY

L

=

PISTBY

2

F

SW

Where:
L

isthe primaryinductance of the transformer.

P

F

is the normal switching frequency.

SW

I

is the minimum controllable current,

STBY

corresponding to the minimum on time that the
deviceis able to provide in normal operation.This
current can be computed as :

I

STBY

b

=

IN

L

P

+ td) V

(t

tb+tdis the sum of the blanking time and of the
propagation time of the internal current sense
and comparator, and represents roughly the
minimum on time of the device. Note that P

STBY

may be affectedby the efficiency of the converter
at low load, and must include the power drawn on
the primaryauxiliary voltage.

As soon as the power goes below this limit, the
auxiliary secondary voltage starts to increase
above the 13V regulation level forcing the output
voltage of the transconductance amplifier to low
state (V

COMP

<V

). This situation leads to

COMPth

the shutdown mode where the power switch is
maintained in the off state, resulting in missing
cycles and zero duty cycle. As soon as V
back to the regulation level and the V

gets

DD

COMPth

threshold is reached, the device operates again.
The above cycle repeats indefinitely, providing a
burst mode of which the effective duty cycle is
much lower than the minimum one when in
normal operation. The equivalent switching
frequency is also lower than the normal one,
leading to a reduced consumption on the input
mains lines. This mode of operation allows the
VIPer20/20A to meet the new German ”Blue
Angel” Norm with less than 1W total power
consumption for the system when working in
stand-by. The output voltage remains regulated
around the normal level, with a low frequency
ripple corresponding to the burst mode. The
amplitude of this ripple is low, because of the
output capacitors and of the low output current
drawn in such conditions.The normal operation
resumes automatically when the power get back
to higherlevels than P

STBY

.

HIGH VOLTAGE START-UP CURRENT
SOURCE

An integrated high voltage current source
provides a bias current from the DRAIN pin
during the start-up phase. This current ispartially
absorbed by internal control circuits which are

12/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

placed into a standby mode with reduced
consumption and also provided to the external
capacitor connected to the V

pin. As soon as

DD

the voltage on this pin reaches the high voltage
threshold V

of the UVLO logic, the device

DDon

turns into active mode and starts switching. The
start up current generator is switched off, and the
converter should normally provide the needed
current on the V

pin through the auxiliary

DD

winding of the transformer, as shown on figure

15.
In case of abnormal condition where the auxiliary

winding is unable to provide the low voltage
supply current to the V

pin (i.e. short circuit on

DD

the output of the converter), the external
capacitor discharges itself down to the low
threshold voltage V

of the UVLO logic, and

DDoff

the device get back to the inactive state where
the internal circuits are in standby mode and the
start up current source is activated. The converter
enters a endless start up cycle, with a start-up
duty cycle defined by the ratio of charging current
towards discharging when the VIPer20/20A tries
to start. This ratio is fixed by design to 2 to 15,
which gives a 12% start up duty cycle while the
power dissipation at start up is approximately 0.6
W, for a 230Vrms input voltage. Thislow value of
start-up duty cycle prevents the stress of the
output rectifiers and of the transformer when in

short circuit.
The external capacitor C

on the VDDpin must

VDD

be sized according to the time needed by the
converter to start up, when the device starts
switching. This time t

depends on many

SS

parameters, among which transformer design,
output capacitors, soft start feature and
compensation network implemented on the
COMP pin. The following formula can be used for
definingthe minimum capacitor needed:

I

DDtSS

>

C

VDD

V

DDhyst

where:
I

is the consumption current on the VDDpin

DD

when switching. Refer to specified I

DD1

and I

DD2

values.
t

is the start up time of the converter when the

SS

device begins to switch. Worst case is generally
at fullload.

V

DDhyst

is the voltage hysteresis of the UVLO

logic. Refer to the minimumspecifiedvalue.
Soft start feature can be implemented on the

COMP pin through a simple capacitor which will
be also used as the compensation network. In
this case, the regulation loop bandwidth is rather
low, because of the large value of this capacitor.
In case a large regulation loop bandwidth is
mandatory, the schematics of figure 16 can be

Figure15: Behaviourof the high voltage current source at start-up

VDD

VDDon

VDDoff

t

Auxiliary pr imary

win ding

2mA

15 mA

CVDD

VDD

15 mA1mA

Ref.

UNDERVOLTAGE
LOCK OUT LOGIC

VIPer 20

Startupdutycycle~12%

3mA

DRAIN

SOURCE

FC00101A

13/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

used. It mixes a high performance compensation
network together with a separate high value soft
start capacitor. Both soft start time and regulation
loop bandwidth can be adjusted separately.

If the device is intentionallyshut down by putting
the COMP pin to ground, the device is also
performingstart-up cycles, and theV
oscillatingbetween V

DDon

and V

DDoff

voltage is

DD

. This voltage
can be used for supplying external functions,
provided that their consumption doesn’t exceed

0.5mA. Figure 17 shows a typical application of
this function, with a latchedshut down. Once the
”Shutdown” signal has been activated, the device
remains in the off state until the input voltage is
removed.

TRANSCONDUCTANCE ERROR AMPLIFIER

The VIPer20/20A includes a transconductance
error amplifier. Transconductance Gm is the
change in output current (I
in input voltage (V

I

∂

COMP

=

G

m

∂ V

DD

The output impedanceZ

). Thus:

DD

COMP

) versus change

COMP

at the output of this

amplifier (COMPpin) can be defined as:
Z

COMP

∂V

COMP

=

∂ I

=

COMP

G

∂ V

1

m

COMP

x

∂ V

DD

This last equation shows that the open loop gain
A

canbe related to GmandZ

VOL

A

VOL=GmxZCOMP

COMP

:

where Gmvalue for VIPer20/20A is 1.5 mA/V
typically.

is well defined by specification, but Z

G

m

and therefore A

are subject to large

VOL

COMP

tolerances. An impedance Z can be connected
between the COMP pin and ground in order to
define more accurately the transfer function F of
the error amplifier, according to the following
equation,very similar to the one above:

F

=Gm x Z(S)

(S)

The error amplifier frequency response is
reported in figure 10 for different values of a
simple resistance connected on the COMP pin.
The unloaded transconductance error amplifier
shows an internal Z

of about 330 KΩ. More

COMP

complex impedance can be connected on the
COMP pin to achieve different compensation
laws. A capacitor will provide an integrator
function, thus eliminating the DC static error, and
a resistance in seriesleads to a flat gain at higher
frequency, insuring a correct phase margin. This
configurationis illustrated on figure18.

As shown in figure 18 an additional noise filtering
capacitor of 2.2 nF is generally needed to avoid
any highfrequency interference.

It can be also interesting to implement a slope
compensation when working in continuous mode
with duty cycle higherthan 50%. Figure 19 shows
such a configuration. Note that R1 and C2 build
the classical compensation network, and Q1 is
injecting the slope compensation with the correct
polarity from the oscillatorsawtooth.

EXTERNALCLOCK SYNCHRONIZATION:

The OSC pin provides a synchronisation
capability, when connected to an external

Figure16: MixedSoft Start and Compensation

D2

+

14/21

VIPer20

OSC

C3

-

13V

+

C4

DRAINVDD

COMP SOURCE

R1

C1

D1

C2

+

D3

R3

R2

FC00431

AUXILIARY
WINDING

Figure17: Latched Shut Down

R1

Shutdown

Q2

R4

OSC

R2R3

Q1

VIPer20

-

13V

+

D1

DRAINVDD

COMP SOURCE

FC00440

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

frequency source. Figure 20 shows one possible
schematic to be adapted depending the specific
needs. If the proposed schematic is used, the
pulse duration must be kept at a low value (500ns
is sufficient) for minimizing consumption. The
optocoupler must be able to provide 20mA
through the optotransistor.

PRIMARY PEAK CURRENT LIMITATION

The primary I

DPEAK

current and, as resulting
effect, the output power can be limited using the
simple circuit shown in figure 21. The circuit
based on Q1, R

and R2clamps the voltage on

1

the COMP pin in order to limit the primary peak
current of the device to a value:

Figure18: TypicalCompensation Network

VIPer20

DRAINVDD

COMP SOURCE

R1

C1

OSC

13V

-

+

C2

I

DPEAK

V

=

COMP

H

− 0.5

ID

where:

R

+ R

1

V

COMP

= 0.6 x

2

R

2

The suggestedvalue for R1+R2is in the range of
220KΩ.

OVER-TEMPERATUREPROTECTION:

Over-temperature protection is based on chip
temperature sensing. The minimum junction
temperature at which over-temperature cut-out
occurs is 140

o

C while the typical value is 170oC.
The device is automatically restarted when the
junction temperature decreases to the restart
temperaturethreshold that is typically40

o

C below

Figure19: Slope Compensation

R1R2

OSC

Q1

VIPer20

-

13V

+

C2

DRAINVDD

COMP SOURCE

C3

C1 R3

FC00451

FC00461

Figure20:ExternalClock Synchronization Figure 21:CurrentLimitationCircuitExample

VIPer20

DRAINVDD

COMP SOURCE

Q1

FC00480

10 kΩ

OSC

13V

VIPer20

­+

DRAINVDD

COMP SOURCE

FC00470

OSC

13V

­+

R1

R2

15/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

Figure22: Recommendedlayout

T1

D1

Tosecondary

D2

C7

filtering and load

From input

diodesbridge

R1

C1

C2

1

U1
VIPerXX0

OSC

2

-

+

13V

ISO1

COMP SOURCE

R2

C3

C4

LAYOUTCONSIDERATIONS

Some simple rules insure a correct running of
switching power supplies. They may be classified
into two categories:

- To minimisepower loops: the waythe switched

power current must be carefully analysed and
the corresponding paths must present the
smallest inner loop area as possible. This
avoids radiated EMC noises, conducted EMC
noises by magnetic coupling, and provides a
better efficiency by eliminating parasitic
inductances,especially on secondaryside.

- To usedifferent tracks for low level signals and

3

DRAINVDD

C5

5

4

C6

FC00500

power ones. The interferencesdue to a mixing
of signal and power may result in instabilities
and/or anomalous behaviour of the device in
case of violent power surge (Input
overvoltages,output short circuits...).

In case of VIPer, these rules apply as shown on
figure 22. The loops C1-T1-U1, C5-D2-T1,
C7-D1-T1 must be minimised. C6 must be as
close as possible from T1. The signal
components C2, ISO1, C3 and C4 are using a
dedicated track to be connected directly to the
sourceof the device.

16/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

PENTAWATT HV (VERTICAL) MECHANICAL DATA

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

mm inch

A 4.30 4.80 0.169 0.189
C 1.17 1.37 0.046 0.054
D 2.40 2.80 0.094 0.110
E 0.35 0.55 0.014 0.022
F 0.60 0.80 0.024 0.031

G1 4.90 5.28 0.193 0.208
G2 7.42 7.82 0.292 0.308
H1 9.30 9.70 0.366 0.382
H2 10.40 0.409
H3 10.05 10.40 0.396 0.409

L 16.60 17.30 0.653 0.681

L1 14.60 15.22 0.575 0.599
L2 21.20 21.85 0.835 0.860
L3 22.20 22.82 0.874 0.898
L5 2.60 3.00 0.102 0.118
L6 15.10 15.80 0.594 0.622
L7 6.00 6.60 0.236 0.260

M 2.50 3.10 0.098 0.122

M1 7.56 8.16 0.298 0.321

R 0.50 0.020

V4 90

o

90

Diam. 3.70 3.90 0.146 0.154

G2

G1

M1

M

leads

E

Resin

between

V4

F

L

L1

A

L5

H1

C

H3

H2

Diam

P023H3

R

D

L6

L7

L2

L3

17/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

PENTAWATT HV 022Y(VERTICAL HIGH PITCH) MECHANICAL DATA

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

mm inch

A 4.30 4.80 0.169 0.189
C 1.17 1.37 0.046 0.054
D 2.40 2.80 0.094 0.110
E 0.35 0.55 0.014 0.022

F 0.60 0.80 0.024 0.031
G1 4.90 5.28 0.193 0.208
G2 7.42 7.82 0.292 0.308
H1 9.30 9.70 0.366 0.382
H2 10.40 0.409
H3 10.05 10.40 0.396 0.409

L 16.42 17.42 0.646 0.686
L1 14.60 15.22 0.575 0.599
L3 20.52 21.52 0.808 0.847
L5 2.60 3.00 0.102 0.118
L6 15.10 15.80 0.594 0.622
L7 6.00 6.60 0.236 0.260

M 2.50 3.10 0.098 0.122

M1 5.00 5.70 0.197 0.224

R 0.50 0.020

V4 90

o

90

o

Diam. 3.70 3.90 0.146 0.154

G2

M1

G1

M

leads

E

Resin

between

F

L

L1

A

R

V4

D

L6

L7

L3

L5

H1

C

H3

H2

Diam

P023H2

18/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

PowerSO-10 MECHANICAL DATA

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

mm inch

A 3.35 3.65 0.132 0.144

A1 0.00 0.10 0.000 0.004

B 0.40 0.60 0.016 0.024
C 0.35 0.55 0.013 0.022
D 9.40 9.60 0.370 0.378

D1 7.40 7.60 0.291 0.300

e 1.27 0.050

E 9.30 9.50 0.366 0.374

E1 7.20 7.40 0.283 0.291
E2 7.20 7.60 0.283 0.300
E3 6.10 6.35 0.240 0.250
E4 5.90 6.10 0.232 0.240

F 1.25 1.35 0.049 0.053

h 0.50 0.002
H 13.80 14.40 0.543 0.567

L 1.20 1.80 0.047 0.071

q 1.70 0.067

α 0

o

o

8

==

==

HE

h

A

F

A1

610

51

eB

M

0.25

D

==

D1

==

E2

==

DETAIL”A”

DETAIL”A”

Q

B

0.10 A

E1E3

==

SEATING
PLANE

A

C

α

B

E4

==

SEATING

PLANE

A1

L

==

0068039-C

19/21

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

Plastic DIP8 MECHANICAL DATA

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 3.3 0.130

a1 0.7 0.028

B 1.39 1.65 0.055 0.065

B1 0.91 1.04 0.036 0.041

b 0.5 0.020

b1 0.38 0.5 0.015 0.020

D 9.8 0.386

E 8.8 0.346

e 2.54 0.100

e3 7.62 0.300
e4 7.62 0.300

F 7.1 0.280

I 4.8 0.189
L 3.3 0.130
Z 0.44 1.6 0.017 0.063

mm inch

20/21

P001F

VIPer20/SP/DIP- VIPer20A/ASP/ADIP

Information furnished isbelieved 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 result from its use. No license is
granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are
subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
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21/21