AN-9741
APPLICATION NOTE
Design Example Using FL103M
Table 1.
Cable Compensation
Device
FL103M
Application
LED Bulb
Input
85V
AC
~ 265V
AC
(50Hz/60Hz)
Output
8.4W (24V/0.36A)
Description
System Specifications
Minimum Line Input Voltage
Maximum Line Input Voltage
Line Frequency
Setting Output Voltage
Input
Output Voltage at Point B
Minimum Output Voltage
Normal Output Current
Second Diode Voltage Drop
Normal Switching Frequency
Switching Frequency between Point B and Point C
Estimated Efficiency
Input
Efficiency
Secondary-Side Efficiency
Input Power
Input Power of Transformer
Overall Efficiency at Point B
Secondary-Side Efficiency at Point B
Output
Input Power at Point B
Input Power of Transformer at Point B
Overall Efficiency at Point C
Secondary Side Efficiency at Point C
Input Power at Point C
Input Power of Transformer at Point C
Determine DC Link Capacitor & DC Link Voltage Range
Input
DC Link Capacitor
Minimum DC Link Voltage
Output
Maximum DC Link Voltage
Minimum DC Link Voltage at Point B
Minimum DC Link Voltage at Point C
Determine the Transformer Turn Ratio
Maximum V
DD
Minimum V
DD
Input
V
DD
Ripple in Burst Mode
V
DD
Diode Drop Voltage
Determine N
P
/N
S
Ratio
Determine N
A
/N
S
Ratio
Symbol
V
LINE
V
LINE
f
L
V
O
V
O
N
min
Value
85
265
60
24
12
10
0.35
1.1
50
33
0.80
0.93
10.50
9.05
0.77
0.89
5.48
4.72
0.75
0.87
4.64
4.00
20
86
375
104
107
24.0
8.0
3.8
0.7
3.20
0.68
Unit
V
AC
V
AC
Hz
V
V
V
A
V
kHz
kHz
max
V
O@B
min
N
I
O
V
F
f
S
f
SR
η
η
S
P
IN
P
IN_T
η
@B
η
S@B
P
IN@B
P
IN_T@B
η
@C
η
S@C
P
IN@C
P
IN_T@C
C
DL
V
DL
V
DL
min
max
min
min
W
F
V
DL@B
V
V
DL@C
V
DD
V
DD
max
min
V
DD
V
V
P-P
V
ripple
V
FA
N
P
/N
S
N
A
/N
s
Continued on the following page…
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.0 • 6/27/11
www.fairchildsemi.com
8
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