Fairchild FPS Series, Руководство по конструкции

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www.fairchildsemi.com/fps
FPS
™
Design Guide
Examples of Typical Application Circuits
85V-265VAC input
5V/2A output
Lp = 2400uH 114/9/4 EF20 (on Vogt Fi324)
fsw = 70kHz
1
2
8
6 3
4
1
2
1
2 3
4
VStr
5
Drain
7
Drain
8
GND
1
Vcc
2
VFB
3
Drain
6
Ipk
4
1
2
3
4
C101
22uF
400V +
R103
10R
0.6W
L100
C202
220uF
50V
+
T1
VOGT EF20
CONN101
B2P3-VH
R104
4.7K
0.6W
IC2
H11A817A.W
C300
Y1
R201
120R
0.6W
R102
100k
2W
D104
1N4007
D101
1N4007
D102
1N4007
L101
L201
2.7uH
D106
1N4148
FS101
230V/3A
R101
C103
2.2nF
1000V
D103
1N4007
IC1
FSDM0265RN
D202
BZX84C3V9
0.5W
C102
22uF
400V +
C201
220uF
50V
+
C105
1uF
50V
D105
UF4007
C104
100nF
50V
CONN201
B4P-VH
D201
SB540
10W Single Output Isolated Flyback Using FSDM0265RN and Zener Diode
Typical Application – Power bricks and single-phase frequency inverters
The FSDM0265RN contains a PWM controller and a MOSFET on two different chips. The 650V MOSFET is fully avalanche rated
and tested which leads to increased system reliability. This application shows a cost reduced feedback circuit using a Zener diode.
R104 is used to reduce the current limit. Higher power parts in the green FPS™ family have a higher current limit and a lower R
DS(on)
than the lower power parts. Using a lower R
DS(on)
part increases the efficiency, particularly at low input voltages. So replacing a low
power part with a high power part increases the efficiency but also the current limit. If it were not possible to reduce the current limit,
the flyback transformer would have to be rated at the higher current limit, making it more expensive.
• FSDM0265RN has a fully avalanche rated MOSFET
– Robust performance under transient conditions
• Overload protection circuit distinguishes between temporary and permanent overload
– Device does not shut down during load surge conditions
– Inherent short circuit protection
• Current limit may be lowered using an external resistor
– Increased flexibility in choice of range of FPS™ parts
Fairchild Devices Description
FSDM0265RN Fairchild Power Switch (1.5A/70kHz)
BZX84C3V9 Zener Diode (3.9V)
H11A817A Transistor Optocoupler
SB540 Schottky Diode (5A/40V)
UF4007 Fast Recovery Diode (1A/1000V)
1N4007 General Purpose Diode (1A/1000V)
1N4148 General Purpose Diode (10mA/100V)