AN1246
Application note
VIPower: auxiliary BIAS power supply using VIPer20A-E
Introduction
This application note describes a bias power supply to meet the needs of powering up Power MOSFETs as well as providing standby power when the main unit is off.
The VIPer20ADIP-E, a part of STMicroelectronics proprietary VIPower (Vertical Intelligent Power), is a current mode PWM with a 700 V avalanche rugged Power MOSFET. It uses a fabrication process which allows the integration of analog control circuits with a vertical power device on the same chip. It can provide an output of 10 W power capability for wide range input, or 20 W for single input voltage range.
October 2007 |
Rev 4 |
1/8 |
www.st.com
Contents |
AN1246 |
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Contents
1 |
Key features of the VIPer20ADIP-E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
3 |
2 |
General circuit description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
3 |
3 |
Connecting the demoboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
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4 |
Layout considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
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5 |
Burst mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
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Performance and cost consideration . . . . . . . . . . . . . . . . . . . . . . . . . . . |
7 |
7 |
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
7 |
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AN1246 |
Key features of the VIPer20ADIP-E |
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1Key features of the VIPer20ADIP-E
■Adjustable switching frequency up to 200 kHz
■Current mode control
■Burst mode operation in standby mode, meets “Blue Angel” standards
■Undervoltage lock-out with hysteresis
■Integrated start-up supply
■Avalanche rugged
■Overtemperature protection
■Primary or secondary regulation general circuit description
This demo board (see schematic in Figure 1) is a 110 to 375 VDC input discontinuous flyback, working at 100 kHz. The output can deliver 12 V at 0.5 A continuous. This circuit can be powered from the main bulk capacitors of an off-line power supply, power factor correction output stage, or the AC line with the addition of a low current bridge rectifier. It benefits from the EMI filter present in a typical power supply. The output uses a Schottky diode for better efficiency. C7 is a low ESR capacitor which manages the ripple current. IC2 provides the reference and the feedback to tightly regulate the output. CS5, CS6, and RS3 form the feedback loop compensation to optimize stability during transients. The demoboard can be tested with convection air. Depending on the final application, air flow might be needed to keep the VIPer20ADIP-E under the thermal shutdown limit.
Figure 1. |
Schematic |
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J1 |
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R9 |
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F1 |
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2 |
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3.9 |
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1 |
0.5 A Pico Fuse |
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D1 |
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T1 |
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CON |
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BYT11-600 |
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Cramer Coil CSM 1608-027 |
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C12 |
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4 |
6 |
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220pF |
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RS14 |
C10 |
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1KV |
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82K |
220pF |
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128T |
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1KV |
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16T |
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3 |
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2 |
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RS4 |
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DS3 |
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14T |
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1.6 |
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LL4148 |
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7 |
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1 |
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C2 |
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4.7uF |
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400V |
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c9 |
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2.2n |
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Y cap |
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C3 |
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120uF |
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RS2 |
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16V |
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4.99K |
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8 |
IC1 |
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1 |
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RS10 |
drain |
osc |
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nu |
7 |
drain |
vdd |
2 |
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6 |
drain |
source |
3 |
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5 |
drain |
comp |
4 |
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VIPer20ADIP-E |
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CS5 |
CS6 |
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CS4 |
33n |
.47u |
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3.9nF |
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D4 |
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NU |
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RS3 |
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5.1k |
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DS2
STPS1H100A
C7
680uF
16V
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R6 |
R8 |
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150 |
1.2k |
4 |
1 |
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IC3 |
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H11A817A |
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3 |
2 |
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C |
IC2 |
CS11 |
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TL431 |
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R |
47n |
A
L2 |
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10uH |
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J2 |
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1 |
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2 |
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C8 |
R11 |
CON |
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330uF |
2.7k |
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16V |
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R7
5.23k
RS5
1.37k
3/8