Fairchild FPS Series, Design Manual

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www.fairchildsemi.com/fps
FPS
™
Design Guide
Examples of Typical Application Circuits
85V-265VAC input
16W output
Lp = 1000uH EF25 (on Vogt Fi324 core)
Primary 80 turns
Vcc 14 turns
5V 6 turns
3.3V 4 turns
6.6V 8 turns
12V 14 turns
1
6
7
8
9
10
5
3
4
VIN
3
GND
1
VOUT
2
- ~
~
+
VStr
5
Drain
7
Drain
8
GND
1
Vcc
2
VFB
3
Drain
6
ILim
4
1 2
VIN
3
GND
1
VOUT
2
1
2 3
4
2
3
1
C11
220uF
16V +
R201
220R
0.6W
T1
C7
1000uF
16V
+
D103
1N4148
R110
D12
SB360
L3
56uH
D14
SB360
IC4
FAN1112D
DF10M
BR101
R205
5.6K
0.6W
R103
22R
0.6W
C14
220uF
16V +
C9
100nF
63V
R202
1K
0.6W
IC1
FSDM0265RN
C103
10uF
50V +
FS1
230V/3A
C102
10nF
1000V
R102
10k
2W
C15
47uF
25V
+
CONN1
B2P3-VH
D15
SB180
C110
275V
C2
100nF
63V
C12
2200uF
16V +
C10
100nF
63V
R203
2.2K
0.6W
L4
56uH
C104
33uF
50V
C206
100nF
100V
IC5
FAN1616AS25
T3
C101
47uF
400V
+
IC2
H11A817A
R105
2.2k
0.6W
C5
100nF
63V
C16
2200uF
16V +
IC3
KA431LZ
C300
250V
R204
1.2K
0.6W
D13
SB330
D102
UF4007
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V 0V
0V
12V/100mA
6.6V/0.7A
5V/1.2A
(incl 2.5V load)
2.5V
3.3V/1.2A
(incl 1.2V load)
1.2V
The isolated, multiple output application shown is suited to applications requiring all of the common logic supply voltages: 5V, 3.3V,
2.5V and 1.2V. The flyback architecture is easily expandable: two additional outputs at 12V and 6.6V are shown in this application.
The design is scalable to higher power levels by changing the size of the FPS™ device and the transformer. The FSDM0265RN uses
current mode control which provides excellent response to line and load transient conditions. The flexible overload protection can
distinguish between a temporary current surge and a longer term overload condition. The over current latch is a current limit which
is active even during the blanking time. This provides additional system robustness against a secondary diode short circuit condition.
• FSDM0265RN has a fully avalanche rated MOSFET with overcurrent latch
– Robust performance under transient conditions
– Device switches off if there is a secondary diode short
• 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)
FAN1112D Voltage Regulator (1.2V/1A)
FAN1616AS25 Voltage Regulator (2.5A/0.5A)
H11A817A Transistor Optocoupler
KA431 2.5V Reference (2.5V)
DF10M Bridge Rectifier
16W Multiple Output Isolated Flyback Converter Using FSDM0265RN
Typical Application – Set top boxes, decoders, and small DVD players
Industrial and communications applications using FPGAs and complex logic chips
Fairchild Devices Description
SB180 Schottky Diode (1A/80V)
SB330 Schottky Diode (3A/30V)
SB360 Schottky Diode (3A/60V)
UF4007 Fast Recovery Diode (1A/1000V)
1N4148 General Purpose Diode (10mA/100V)