Application Note Ultra Wide Input Range, HV-BIAS Supply for SMPS

Version 1.1, March 2008
Application Note
CoolSET™ & CoolMOS™
Ultra Wide Input Range, HV-BIAS Supply for SMPS
with ICE2B265 and SPA02N80
Author:
Bernd Ilchmann
Finepower GmbH
Published by Infineon Technologies AG
http://www.infineon.com/coolset
Power Management & Supply
N e v e r
s t o p
t h i n k i n g
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
Contents:
1 Short Description..................................................................................................................... 3
2 Features .................................................................................................................................. 3
3 General Description ................................................................................................................ 4
4 Description of Function and Components .............................................................................. 5
5 Results..................................................................................................................................... 7
5.1 Output Voltage ..............................................................................................................7
5.2 Cross Regulation ...........................................................................................................7
5.3 Protection Features....................................................................................................
........8
5.4 Efficiency ......................................................................................................................9
6 Construction .......................................................................................................................... 10
7 Bill of Materials ...................................................................................................................... 11
8 References ............................................................................................................................ 13
WARNING !
This bias power supply board works with mortally high voltage!
Furthermore, parts of the circuitry are not insulated from the line
input. The user has to make sure that no danger or risk can occur
for himself or for any other person while voltage is applied to this
board.
Dependant on the final application this converter must be protected
by a fuse or any other element which can disconnect the applied
maximum voltage of 800V DC in case of failure.
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Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
1 Short Description
This application note describes a universal ultra wide input voltage range power supply module. It is
typically used as housekeeping power supply in professional SMPS. Typically driven from the bulk
capacitor after any PFC stage or from the bulk after a three phase rectifier any DC input voltage from
120V DC to 800V DC may be applied to this board. It provides a primary (line connected) output voltage
as well as a secondary (line isolated) output voltage of 15V DC (both). The sum of the output power is
up to 12W shared to both outputs.
One typical application is shown in figure 1 below.
Figure 1: Principle application of the HV-Bias circuit
2 Features
The 12W HV -BIAS demonstration board shows a complete two-output DC to DC Flyback circuit. To
achieve an ultra wide input voltage range up to 800VDC a transistor with 1200V to 1500V breakdown
capability is necessary. This makes the design expensive and reduces the efficiency by its parasitics.
On this HV-Bias module Infineon’s 600V CoolSET™ is used together with a further 600V or 800V
CoolMOS™ transistor.
The user of this module is able to supply any primary or secondary connected circuitry (µC’s, PWM’s,
drivers, relays etc.) independent from the state (short circuit, no load, stand-by or remote-off) of the
main SMPS system.
Page 3 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
By connecting the input terminals of the CoolBIAS Module across a line filter, rectifier and a sufficient
bulk capacitor to the AC line a universal ultra wide input range AC power supply is realizable.
A very high reliability of this module due to the CoolSET’s protection features and robustness of the
integrated and external CoolMOS transistor is achieved.
Technical specification:
1)
Input Voltage Range:
120 VDC ... 800V DC
Total Output Power:
12W
Output Power Limit:
ca. 15W
Output 1 Voltage, primary:
15V DC ± 8%
Output 2 Voltage, secondary:
15V DC ± 12%
Short Circuit protection:
yes, with auto restart
Efficiency (typ.) @ rated load:
73 ...83 %
Switching Frequency:
67kHz
PWM & Power Device:
ICE2B265 & SPA02N80
2)
2)
3)
4)
1)
Start-up behavior – see text
2)
Output 1 & 2 Load Sharing: from 80% / 20% up to 20% / 80%
3)
Depending on input voltage
4)
SPA02N80 may be replaced by a (cheaper) 600V CoolMOS if input voltage
overshoot is limited to 800V.
3 General Description
The input of the HV-Bias module can be connected to any bulk (after rectification) from 115V AC single
phase up to 400V AC multi phase AC front end as well as to the bulk after any PFC stage. Due to the
very high maximum input voltage of 800V DC and the reflected output voltage of approx. 200V the
breakdown capability of the internal switch in the ICE2B265 is exceeded as well as in its high voltage
version (ICE2A280).
A series connection of a cheap 600V or 800V CoolMOS™ transistor with the internal CoolSET™
MOSFET forms a self driven cascode witch is able to handle a maximum drain voltage above 1kV.
The circuit around the CoolSET™ is very similar to the standard application and not described in this
paper therefore.
Page 4 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
Fig. 2: Principle Application of the CoolBIAS Power Supply
Figure 2 shows the complete schematic of the HV-Bias module. Beside the standard CoolSET™
periphery only few additional components are required to achieve the high voltage capability of the
power switch.
4 Description of Function and Components
The function of the self driven cascode essentially depends on the chosen zener diode D4. After
applying the high input voltage C3 is charging across R1 to R4. Furthermore, these resistors do share
the input voltage across the serial connected input electrolytic capacitors. The gate voltage of Q1
(across R7 to R10) tracks the input voltage until it is clamped by D4 to approx. 550V. Due to the
source follower circuitry of Q1 the maximum drain voltage for IC1 is limited around the voltage across
D4.
Page 5 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
When C3 is charged up to the start voltage of IC1 the internal MOSFET will switch on and forces the
source of the external MOSFET Q1 close to GND. The charge in the junction of the high voltage zener
is transferred across R11 to the gate of Q1. D6 limits its maximum gate voltage to 15V. By this way
both MOSFET’s switch on nearly simultaneously. The transformers primary winding is applied to the
input voltage now.
When the PWM controller of IC1 switches off - the internal MOSFET disconnects the transformer’s
primary winding from the input. So the voltage across the opened CoolSET™ switch rises (driven by
the stored inductive energy) until it is clamped by the source follower Q1. Because the source of Q1
was held down by IC1 before, the gate voltage of Q1 was approx. 15V. So the fast rising drain voltage
of IC1 switches off Q1 nearly in the same time (when the voltage is higher than approx. 12V). The
increasing voltage charges the junction of D4 across D6, R11 until it is clamping. From now the
voltage follower Q1 starts working and stops further increasing of the voltage across IC1. So any
additional voltage increases across Q1 until its maximum value.
VIN = 280V DC
VIN = 400V DC
VIN = 600V DC
VIN = 800V DC
Figure 3: From top to bottom: VD-GND (Q1), VD-S (Q1), VD-GND (CoolSET™)
Page 6 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
5 Results
5.1 Output Voltage
The nominal Output voltage on the primary as well as on the secondary side is 15V DC. By a 2% zener
diode and a resistive divider this value is realized in a sufficient accuracy. Due to the primary located
regulation loop the primary output voltage is quite exact and no dependant from line and load changes
on the secondary side. So no clamping zener diode is required to protect the IC from over voltage. If in
any application only one (primary) output voltage is required, the user may connect the secondary
output parallel to the primary. Figure 4 shows the primary and secondary output voltage versus VIN .
Vo = f(Vin); param. Load
16
15,8
15,6
Vo / Vdc
15,4
15,2
15
UO(P,S) @ full load
UO(P,S) @ half load
14,8
14,6
14,4
14,2
14
100
200
300
400
500
600
700
800
Vin / Vdc
Figure 4: Line Regulation at half and full load
5.2 Cross Regulation
The inductive coupled secondary output voltage follows the regulated voltage with a tolerance caused
by the leakage inductance between the primary bias and the secondary winding. Additionally, some
tolerances in the rectifier diode (forward voltage or temperature) may cause deviation. However, the
secondary unregulated output voltage under balanced load sharing tracks the primary voltage very
excellent due to the optimized transformer design. Under cross load condition (20%/80% up to
80%20%) the secondary output voltage stays within the designated tolerances. Figure 5 shows the
cross load behavior of the secondary output voltage.
Page 7 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
Cross Regulation @ Vin = 400V20
Output Voltage
18
16
VO(P) / V
14
VO(S) / V
12
10
8
0%
20%
40%
60%
80%
100%
Primary Load Ratio
Fig. 5: Cross Regulation while secondary side is shunted with 1k?
5.3 Protection Features
Shorted output on the primary side as well as on the secondary side cause the hiccup mode of the
controller with no rising of any output voltage. After removing the output short the converter starts
automatically.
The output power limit, adjusted by the value of the current sense resistor is set to approx. 15W. By
exceeding the output power above this limit the converter goes into the hiccup mode with auto restart
as well as under short condition. This avoids excessive stress from any device. By removing R5 from
the board the primary regulation loop is cut off. Usually, the output voltage of any flyback converter is
rising up to the energy limit, destroying the connected circuitry and the converter. In the described
HV-BIAS module a self protection against this failure is introduced in the controller circuit. The PWM
controller is detecting the loss of the regulation loop and switches to the hiccup mode.
Figure 6 demonstrates that the overload shutdown which is relatively constant over the ultra wide input
voltage range due to the adaptive overload threshold in the CoolSET™-PWM.
Page 8 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
Over Load Shutdown vs. Input Voltage
20
Overload Power
15
10
5
0
100
200
300
400
500
600
700
800
Input Voltage
Fig. 6: Overload Shutdown versus Input Voltage
In the given design there may be some start-up problems with high external output capacitance at
rated power when starting at low line (120V DC ). Due to the interaction between soft-start capacitance,
current sense resistor and start up current a tuning of these components may be necessary if starting
is required at very low line. After the converter is started, it works down to approx. 100V DC without any
problems.
5.4 Efficiency
The efficiency of the HV-Bias module is not the main criterion for the design due to its low power
consumption. Especially in high voltage or in three phase designs the total transferred power is much
more than the rated power level of this bias module. Furthermore, the efficiency depends on the
increasing switching losses going square with the input voltage. Nevertheless, the overall efficiency of
the converter is sufficient high.
Figure 7 shows the efficieny of the converter versus input voltage at rated output power and half of the
rated output power.
Page 9 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
Efficiency vs. Input Voltage
100%
90%
Effcy. / %
80%
PO(tot) = 12W
70%
PO(tot) = 6W
60%
50%
40%
100
200
300
400
500
600
700
800
Input Voltage / Vdc
Figure 7: Efficiency of the HV-Bias Module versus Input Voltage
6 Construction
The converter is designed on a small double sided PCB. So trough hole devices (transformer, IC1,
Q1, electrolytic capacitors etc.) can be placed on the opposite side from the SMD’s. Figure 8: shows
the PCB layout for the top and bottom side layer.
Figure 8: The HV-Bias Module – nearly original size
Page 10 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
Figure 9: Layout TOP - left and BOTTOM (mirrored) – right
Figure 10: Components placement on the top (left) and the bottom (right) side
7 Bill of Materials (part list)
Part
Value 1
Value 2
Ordering Code
Supplier or
Manufacturer
BR1
Wire bridge 0.6mm
C1
10µF / 450V
electrolytic cap, grid: 5mm
various
C2
10µF / 450V
electrolytic cap, grid: 5mm
various
C3
47µF / 50V
electrolytic cap, grid: 2,5mm
various
C4
470µ / 25V-
Low ESR electrolytic, grid: 5mm
various
C5
330p / 1kV
NP0, grid. 5.08mm
various
Page 11 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
C6
0µ1 / 50V
X7R, SMD1206
various
C7
1µ0 / 25V
X7R, SMD1206
various
C8
2n2 / 50V
NP0, SMD1206
various
C9
1000µ / 25V -
Low ESR electrolytic, grid: 5mm
various
D1
ES3D
Ultra Fast Diode, SMC
Vishay - GS
D2
LL4148
Diode SMD
various
D3
ZMM12
Zener diode 12V, SMD
various
D4
P4KE550
HV-Zener, 550V
Vishay - GS
D5
US1M
Ultra Fast Diode , SMA
Vishay - GS
D6
ZMM15
Zener diode 15V, SMD
various
D7
ES3D
Ultra Fast Diode, SMC
Vishay - GS
IC1
ICE2B265
CoolSET™ PWM + Mosfet
Infineon
Q1
SPA02N60-C3
CoolMOS™ 600V / 2A
Infineon
Q2
MMBT2222
NPN transistor, SOT23
ON Semiconductor
R1
330k / 0,2W
SMD1206
various
R2
330k / 0,2W
SMD1206
various
R3
330k / 0,2W
SMD1206
various
R4
330k / 0,2W
SMD1206
various
R5
3k6 / 0,2W
SMD1206
various
R6
4k7 / 0,2W
SMD1206
various
R7
1M0 / 0,2W
SMD1206
various
R8
1M0 / 0,2W
SMD1206
various
R9
1M0 / 0,2W
SMD1206
various
R10
1M0 / 0,2W
SMD1206
various
R11
10R / 0,2W
SMD1206
various
R12
22R / 0,2W
SMD1206
various
R13
120k / 1W
Metal film, grid 10,16
various
R14
1R8 / 0,2W
SMD1206
various
TF1
UEI18.0
Flyback Transformer
Fa. Lasslop
Page 12 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
8 References
[1]
Infineon Technologies AG: “CoolSET™- F2 Offline SMPS Current Mode Controller with
integrated 650V/800V CoolMOS ” Datasheet; Munich; Germany; 08/2002
http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/prod_ov.jsp?oid=26910&cat_oid=-8179
[2]
Infineon Technologies AG: “SPP02N80C3” 800V CoolMOS™ Transistor; Datasheet;
Munich; Germany; 07/2003
http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/prod_ov.jsp?oid=25591&cat_oid=-8176
[3]
Infineon Technologies AG: (H. Zöllinger, R. Kling) “AN-SMPS-ICE2xXXX-1 – Application
Note: CoolSET ICE2xXXX for OFF-Line Switch Mode Power Supply (SMPS)
Munich; Germany; 02/2002
http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/prod_ov.jsp?oid=26910&cat_oid=-8179
[4]
Infineon Technologies AG: (B. Ilchmann) “6W Bias Supply for SMPS with ICE2A0565Z”;
Application Note: AN-EvalMF2-ICE2A0565Z-1; Munich; Germany; 09/02
http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/prod_ov.jsp?oid=26910&cat_oid=-8179
Page 13 of 14
Ultra Wide Input Range, HV-Bias Supply
for SMPS with ICE1B265 & SPA02N80
Revision History
Application Note AN-EvalMF2-ICE2A0565Z-1
Actual Release: V1.1 Date:11.03.2008
Page of
Page of
actual
prev. Rel.
Previous Release: V1.0
Subjects changed since last release
Rel.
2 of 14
----------
„WARNING“ (Safety Issue regarding fuse protection)
5 of 14
Schematic (Fig. 2) modified
10 of 14
Photo (Fig. 8) updated
11 of 14
Fig. 10: Placement for top side modified
11 of 14
Bill of Material modified (ex F1, add BR1)
For questions on technology, delivery and prices please contact the Infineon Technologies Offices in
Germany or the Infineon Technologies Companies and Representatives worldwide: see the address
list on the last page or our webpage at
http://www.infineon.com
CoolMOS and CoolSET are trademarks of Infineon Technologies AG.
We listen to Your Comments
Any information within this document that you feel is wrong, unclear or missing at all?
Your feedback will help us to continuously improve the quality of this document.
Please send your proposal (including a reference to this document) to:
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Edition 2008-03-11
Published by Infineon Technologies AG,
Am Campeon 1-12
D-81726 München
© Infineon Technologies AG 2000.
All Rights Reserved.
Attention please!
The information herein is given to describe certain components and shall not be considered as warranted characteristics.
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We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts
stated herein.
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For further information on technology, delivery terms and conditions and prices please contact y our nearest Infineon Technologies Office in
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Page 14 of 14
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