STAND-BY CONDI T ION ABLE TO MEET
“BLUE ANGEL” NORM (<1w TOTAL POWER
CONSUMPTION)
■ INTERNALLY TRIMMED ZENER
REFERENCE
■ UNDERVOLTAGE LOCK-OUT WITH
HYSTERESIS
■ INTEGRATED START-UP SUPPLY
■ OVER-TEMPERATURE PROTECTION
■ LOW STAND-BY CURRENT
■ ADJUSTABLE CURRENT LIMITATION
Block Diagr am
PENTAWATT HV
PENTAWATT HV (022Y)
Description
VIPer50-E, made using VIPower M0 Technology,
combines on the same si licon chip a state-of-theart PWM circuit together with a n optimized, high
voltage, Vertical Power MOSFET (620V/ 1.5A).
Typical applications cover offline power supplies
with a secondary power capability of 25W in wide
range condition and 50W in single ran ge 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 ability to operate in stand-by mode
without extra components.
Continuous Drain-Source Voltage (TJ = 25 to 125°C)–0.3 to 620V
Maximum CurrentInternally limitedA
Supply Voltage 0 to 15V
Voltage Range Input0 to V
DD
Voltage Range Input0 to 5V
Maximum Continuous Current±2mA
Electrostati c Discharge (R = 1.5kΩ; C = 100pF)4000V
Avalanche Drai n-Source Current, Repetitive or Not Repetitive
= 100°C; Pulse width limited by TJ max; δ < 1%)
(T
C
1.5 A
Power Dissipati on at TC= 25ºC60W
Junction Operat ing TemperatureInternally limited°C
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 unclamped current during its normal operation, assuring self
protection against voltage surges, PCB stray inductance, and allowing a snubberless operation
for low output power.
3.2 Source Pin:
Power MOSFET source pin. Primary side circuit common ground connection.
3.3 VDD Pin (Powe r Supply):
This pin provides two functions :
●It corresponds to the low volt age supply of t he control part of the circuit. If V
8V, the start-up current source is activated and the output power MOSFET is switched off
until the V
reduced, the V
ground. After that, the current source is shut down, and the device tries to start up by
switching again.
●This pin is also connected to the error amplifier, in order to allow primary as well as
secondary regulation configurations. In case of primary regulation, an internal 13V
trimmed reference voltage is used to maintain V
voltage between 8.5V and 12.5V will be put on V
stuck the output of the transconductance amplifier to the high state. The COMP pin
behaves as a 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
will be somewhat higher than the nominal one, but still under control.
voltage reaches 11V. During this phase, the internal current consumption is
DD
pin is sourcing a current of about 2mA and the COMP pin is shorted to
DD
at 13V. For secondary regulation, a
DD
pin by transformer design, in order to
DD
voltage, which cannot overpass 13V. The output voltage
DD
goes below
DD
3.4 Compensation 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 components value. As
stated above, secondary regulation configurations are also implemented through the
COMP pin.
●When the COMP voltage is going below 0.5V, the shut-down of the circuit occurs, with a
zero duty cycle for the power MOSFET. This feature can be used to switch off the
converter, and is automatically activated by the regulation loop (no matter what the
configuration is) to provide a burst mode operation in case of negligible output power or
open load condition.
8/29
VIPer50-E3 Pin Description
FC00020
3.5 OSC Pin (Oscillator Frequency):
An Rt-Ct network must be connected on that to define the switching frequency. Note that
despite the connection of R
from 8V to 15V. It provides also a synchronisation ca pabilit y, when connected to an external
frequency source.
Figure 1.Connection Diagrams (T o p View)
to VDD, no significant frequency change occurs for VDD varying
t
PENTAWATT HV
Figure 2.Current and Voltage Convention
DD
I
VDD
IOSC
OSC
13V
OSC
V
+
I
VCOMP
COMP SOURCE
COMP
PENTAWATT HV (022Y)
DRAINVDD
D
I
DS
V
9/29
4 T ypical CircuitVIPer50-E
4 Typical Circuit
Figure 3.Offline Power Supply With Auxiliary Supply Feedback
F1
BR1
TR1
D2
D1
C2
R1
C7
L2
+Vcc
C9
AC IN
TR2
C1
R9
D3
C4
C3
R7
R2
DRAINVDD
13V
+
C11
VIPer50
COMP SOURCE
C6
OSC
C5
R3
Figure 4.Offline Power Supply With Optocoupler Feedback
F1
BR1
TR1
D1
C2
C4
R1
D3
C3
R7
AC IN
TR2
C1
R9
GND
C10
FC00301
D2
C10
L2
+Vcc
C9C7
GND
R2
13V
+
C11
COMP SOURCE
C6
R3
OSC
C5
10/29
DRAINVDD
U1
VIPer100
R6
ISO1
R4
U2
C8
R5
FC00091
VIPer50-E5 Operation Description
5 Operation Description
5.1 Current Mode Topology:
The current mode control method, like the one integrated in the VIPer50-E, 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
(the amplified output voltage error) the power switch is
COMP
switched off. Thus, the outer voltage control loop defines the level at which the inner loop
regulates peak current through the power switch and the primary winding of 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 improved line
regulation, instantaneous correction to line changes, and better stability for the voltage
regulation loop.
Current mode topology also ensures good limitation in case there is a short circuit. During the
first phase the output current increases slowly following the dynamic of the regulation loop.
Then it reaches the maximum limitation current internally set and finally stops because the
powe r supply on V
is no longer correct. For specific applications the maximum peak current
DD
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 case there are current spikes caused by primary side
capacitance or secondary side rectifier reverse recovery time.
proportional to this
S
5.2 Stand-by Mode
Stand-by operation in nearly open load conditions 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
Where:
L
is the primary inductance of the transformer. FSW is the normal switching frequency.
P
I
STBY
P
STBY
is the minimum controllable current, corresponding to the minimum on time that the
device is able to provide in normal operation. This current can be computed as :
I
STBY
t
+ td is the sum of the blanking time and of the propagation time of the internal current sense
b
and comparator, and represents roughly the minimum on time of the device. Note: that PSTBY
may be affected by the efficiency of the converter at low load, and must include the power
drawn on the primary auxiliary voltage.
1
-- -L
2
tbtd+()V
-----------------------------=
given by :
STBY
I2STBYFSW=
P
IN
L
p
11/29
5 Operation DescriptionVIPer50-E
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
COMPth
). This situation leads to 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
gets back to the regulation level and the V
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 main supply lines. This mode of operation allows the VIPer50-E to
meet the new German "Blue Angel" Norm with less than 1W total power consumption for the
system when working in stand-by mode. 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 low output current drawn in such
conditions.The normal operation resumes automat ically when the power gets back to higher
levels than P
STBY
.
5.3 High Voltage Start-up Current Suorce
An integrated high voltage current source provides a bias current from the DRAIN pin during
the start-up phase. This current is partially absorbed by internal control circuits which are
placed into a standby mode with reduced consumption and also provided to the external
capacitor connected to the V
threshold V
of the UVLO logic, the device becomes active mode and starts switching. The
DDon
start-up current generator is switched off, and the converter should normally provide the
needed current on the V
(see Figure 11).
pin. As soon as the volt age on t his pi n reaches the high voltage
DD
pin through the auxiliary winding of the transformer, as shown on
DD
In case there are abnormal conditions where the auxiliary winding is unable to provide the low
voltage supply current to the V
external capacitor discharges to the low threshold voltage V
pin (i.e. short circuit on the output of the converter), the
DD
of the UVLO logic, and the
DDoff
device goes 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 startup duty cycle defined by the ratio of charging current towards discharging when the VIPer100E tries to start. This ratio is fixed by design to 2A to 15A, which gives a 12% start-up duty cycle
while the power dissipation at start-up is approximately 0.6W, for a 230Vrms input voltage.
This low value start-up duty cycle prevents the application of stress to the output rectifiers as
well as the transformer when a short circuit occurs.
The external capacitor C
converter to start up, when the device starts switching. This time t
on the VDD pin must be sized according to the time needed by the
VDD
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
defining the minimum capacitor needed:
I
where:
I
DD
C
VDD
is the consumption current on the VDD pin when switching. Refer to specified I
DDtSS
-------------------->
V
DDhyst
and IDD2
DD1
values.
is the start up time of the converter when the device begins to switch. Worst case is
t
SS
generally at full load.
12/29
VIPer50-E5 Operation Description
V
is the voltage hysteresis of the UVLO logic (refer to the minimum specified value).
DDhyst
The soft start feature can be implemented on the COMP pin through a simple capacitor which
will be als o us e d a s the compens ation network . In this case , the regulation lo op bandw idth is
rather low, because of the large value of this capacitor. In case a large regulation loop
bandwidth is mandatory, the schematics of (see Figure 17) can be used. It mixes a high
performance compensation netw ork 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 intentionally shut down by tying the COMP pin to ground, the device is also
performing start-up cycles, and the V
voltage is oscillating between V
DD
This voltage can be used for supplying external functions, provided that their consumption does
not exceed 0.5mA. (see Figure 18) shows a typical application of this function, with a latched
shutdown. Once the "Shutdown" signal has been activated, the device remains in the Off state
until the input voltage is removed.
5.4 Transconductance Error Amplifier
The VIPer50-E includes a transconductance error amplifier. Trans conduc tance Gm is the
change in output current (I
∂l
m
COMP
-------------------=
∂V
COMP
DD
V
∂
COMP
-------------------- -
I
∂
COMP
COMP
-------G
G
The output impedance Z
Z
) versus change in input voltage (VDD). Thus:
COMP
at the output of this amplifier (COMP pin) can be defined as:
V
1
∂
COMP
------------------------ -×==∂V
m
DD
DDon
and V
DDoff
.
This last equation shows that the open loop gain A
= Gm x Z
A
VOL
COMP
can be related to Gm and Z
VOL
COMP
:
where Gm value for VIPer50-E is 1.5 mA/V typically.
is defined by specification, but Z
G
m
and therefore A
COMP
are subject to large tolerances.
VOL
An impedance Z can be connected between the CO MP pin and ground in order to define the
transfer function F of the error amplifier more accurately, 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 330KΩ. More complex impedance can be connected on the COMP
COMP
pin to achieve different compensation level. A capacitor will provide an integrator function, thus
eliminating the DC static error, and a resistance in series leads to a flat gain at hi gher
frequency, insuring a correct phase margin. Thi s configur ation is illustrated in Figure 20
As shown in Figure 19 an additional noise filtering capacitor of 2.2nF is generally needed to
avoid any high frequency interference.
Is also possible to implement a slope compensation when working in continuous mode with
duty cycle higher than 50%. Figure 21 shows such a configuration. Note: R1 and C2 build the
classical compensation network, and Q1 is injecting the slope compensation with the correct
polarity from the oscillator sawtooth.
13/29
5 Operation DescriptionVIPer50-E
5.5 External Clock Synchronization:
The OSC pin provides a synchronisation capability when connected to an external frequency
source. Figure 21 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.
5.6 Primary Peak Current Limitation
The primary I
current and, consequently, the output power can be limited using the
DPEAK
simple circuit shown in Figure 22 . The circuit based on Q1, R
the COMP pin in order to limit the primary peak current of the device to a value:
I
DPEAK
V
COMP
--------------------------------=
0.5–
H
ID
where:
V
COMP
The suggested value for R
0.6
1R2
-------------------×=
R
2
is in the range of 220KΩ.
1+R2
+
R
5.7 Over-Temperature Protection
Over-temperature protection is based on chip temperature sensing. The minimum junction
temperature at which over-temperature cut-out occurs is 140ºC, while the typical value is
170ºC. The device is automatically restarted when the junction temperature decreases to the
restart temperature threshold that is typically 40ºC below the shutdown value (see Figure 13)
Figure 7.Tr an sition TimeFigure 8.Shutdown Action
Slope =
G m i n mA/V
V
DDreg
FC00150
V
I
DD
DD0
I
DDch
VOSC
DDhyst
V
V
DDoff
VDS= 35 V
Fsw = 0
DDon
V
FC00170
V
D
ID
10% Ipeak
DS
90% V D
D
10% V
tf
t
t
tr
FC00160
VCOMP
COMPth
ID
tDISsu
ENABLE
DISABLE
t
t
t
ENABLE
FC0006
Figure 9.Breakdown Voltage vs. Temperature Figure 10. Typical Frequency Variation
1.15
BVDSS
Normalized)
1.05
0.95
1.1
1
0 20406080100120
Temperature (°C)
FC00180
1
%)
0
-1
-2
-3
-4
-5
020406080 100 120
Temperature (°C)
FC00190
15/29
5 Operation Descri ptionVIPer50-E
V
0
Figure 11. Behaviour of the high voltage current source at start-up
VDD
VDDon
DDoff
t
Auxiliary primary
Figure 12. Start-Up W aveforms
winding
2 mA
15 mA
VDD
C
VDD
15 mA1 mA
Ref.
UNDERVOLTAGE
LOCK OUT LOGIC
3 mA
VIPer50
Start up duty cycle ~ 12%
DRAIN
SOURCE
FC0032
16/29
VIPer50-E5 Operation Descri ption
0
00000000
0
0
0
00000
0
0
0
0
00
0
000000
0000
000000
0
0
000000
000
000000
0
0
0
0
0
000000
00
000000
0
000000
0000
000
000000000000
000000000000000000000000000000
000000
000000000000000000000000000000
000
00000000000000000000
0000000000
000000000000000000000000000000
000000
000000000000000000000000000000000000
000000000
00
SC 101 91
T
T
t
t
t
t
Figure 13. Over-temperature Protection
J
T
ts c
tsd-Th yst
V
dd
V
dd on
V
dd off
I
d
V
comp
17/29
5 Operation Descri ptionVIPer50-E
C
C
w
Figure 14. Oscillator
Rt
VDD
OSC
F
CLK
t
Ω
SW
2.3
-----------1
⋅=
R
tCt
550
⎛⎞
--------------------–
⎝⎠
R
150–
t
~360
FC00050
t
Forbidden area
For Rt > 1.2kΩ and Ct ≤ 40KHz
22nF
Ct(nF) =
15nF
880
Fsw(kHz)
1,000
500
300
200
100
Frequency (kHz)
Forbidden area
40kHz
Oscillator frequency vs Rt and Ct
FC00030FC00030
Ct = 1.5 nF
Ct = 2.7 nF
Ct = 4.7 nF
Ct = 10 nF
50
30
123510203050
Rt (kΩ)
Fs
18/29
VIPer50-E5 Operation Descri ption
0
0
Figure 15. Error Amplifier frequency Response
FC00200
60
RCOMP = +
RCOMP = 270k
40
RCOMP = 82k
RCOMP = 27k
RCOMP = 12k
20
Voltage Gain (dB)
0
∞
(20)
0.0010.010.11101001,00
Frequency (kHz)
Figure 16. Error Amplifier Phase Response
200
RCOMP = +
RCOMP = 270k
RCOMP = 82k
RCOMP = 27k
RCOMP = 12k
Phase (°)
150
100
50
0
(50)
0.0010.010.11101001,00
Frequenc y ( k Hz )
FC00210
∞
19/29
5 Operation Descri ptionVIPer50-E
Y
Figure 17. Mixed Soft Start and Compensation Figure 18. Latched Shut Down
D2
VIPer50
OSC
C3
+
+
13V
C4
DRAINVDD
COMP SOURCE
R1
C1
D1
D3
R3
AUXILIAR
WINDING
R2
C2
+
Shutdow n
Q2
R4
R1
OSC
13V
R2R3
Q1
D1
FC00331
Figure 19. Typical Compensation NetworkFigure 20. Slo pe Compensation
VIPer50
DRAINVDD
OSC
13V
-
+
C2
COMP SOURCE
R1
C1
R1R2
OSC
Q1
13V
+
C2
VIPer5 0
COMP SOURCE
C3
VIPer50
-
+
DRAINVDD
DRAINVDD
COMP SOURCE
FC00340
C1R3
FC00351
FC00361
Figure 21. Ex te rnal Clock Sin chronisati onFigure 22. Current Limitation Ci rc u it Example
VIPer50
DRAINVDD
13V
-
+
COMP SOURCE
R1
Q1
R2
FC003 80
10 kΩ
OSC
13V
VIPer50
+
OSC
DRAINVDD
COMP SOURCE
FC00370
20/29
VIPer50-E6 Electrical Over S tr ess
B
g
6 Electrical Over Stress
6.1 Electrical Over Stress Ruggedness
The VIPer may be submitted to electrical over-stress, caused by violent input voltage surges or
lightning. Following the Layout Considerations is sufficient to prevent catastrophic damages
most of the time. However in some cases, the voltage surges coupled through the transformer
auxiliary winding can exceed the V
may trigger the V
discharge current of the V
internal protection circuitry which could be damaged by the strong
DD
bulk capacitor. The simple RC filter shown in Figure 23 can be
DD
implemented to improve the application immunity to such surges.
Figure 23. Input Vol tage Surges Protecti on
pin absolute maximum rating voltage value. Such events
DD
C1
ulk capacitor
C2
22nF
OSC
VIPerXX0
13V
R2
39R
VDD
D1
Auxilliary windin
R1
(Optional)
DRAIN
-
+
COMP
SOURCE
21/29
7 LayoutVIPer50-E
d
d
7 Layout
7.1 Layout Considerations
Some simple rules insure a correct running of switching power supplies. They may be
classified into two categories:
–Minimizing power loops: The switched power current must be carefully analysed and
the corresponding paths must be as small an 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 secondary side.
–Using different tracks for low level and power signals: Interference due to 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 (see Figure 24).
–Loops C1-T1-U1, C5-D2-T1, and C7-D1-T1 must be minimized.
–C6 must be as close as possible to T1.
–Signal components C2, ISO1, C3, and C4 are using a dedicated track connected
directly to the power source of the device.
Figure 24. Recommended Layout
R1
C1
From input
iodes bridge
C2
OSC
U1
VIPerXX0
13V
ISO1
+
COMP SOURCE
C3
T1
D2
DRAINVDD
C5
R2
C4
D1
To s econdary
C7
filtering and loa
C6
FC00500
22/29
VIPer50-E8 Package Mechanical Data
8 Package M echanical Da ta
In order to meet environmental requirements, ST offers these devices in ECOPACK®
packages. These packages have a Lead-free second level interconnect . The category of
second Level Interconnect is marked on the package and on the inner box label, in compliance
with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also
marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are
available at: www.st.com.
Figure 25. Pentawatt HV Tube Shipment ( no suffix )
Base Q.ty50
Bulk Q.ty1000
T ube length ( ± 0.5 )532
A18
B33.1
C ( ± 0. 1)1
All dim e nsions ar e i n mm.
26/29
VIPer50-E9 Order Codes
9 Order Codes
PENT AWATT HVPENTAWATT HV (022Y)
VIPer50-EVIPer50-22-E
27/29
10 Revision historyVIPer50-E
10 Revision history
DateRevisionChanges
26-Sep-20051Initial release.
28/29
VIPer50-E10 Revision history
I
s
o
d
b
ct
t
ot
a
nformation furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequence
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o change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are n
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