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Fairchild Reference Design
The following user guide supports the demonstration kit for the FL7732. It should be
used in conjunction with the FL7732 datasheet as well as Fairchild’s application notes
and technical support team. Please visit Fairchild’s website at www.fairchildsemi.com
Application
Fairchild Device
Input Voltage Range
Output
Power
Output Voltage
(Rated Current)
LED Bulb
FL7732
90-265 VAC
16.8 W
24 V (0.7 A)
Key Features









Cost-Effective Solution: No Input Bulk Capacitor or Feedback Circuitry
Power Factor Correction (PFC)
Accurate Constant-Current (CC) Control
Linear Frequency Control Improves Efficiency and Simplifies Design
Constant Current Regulation vs. Output Voltage Change (11~28 V): <±2.88%
Constant Current Regulation vs. line voltage change (90~265 VAC): <±2.94%
Output-Open & Short-Circuit Protection with Auto Restart
System Efficiency Up to 89%
PF and THD at Nominal Voltages (120 ~ 230 VAC): PF (>0.95), THD (<18%)
© 2012 Fairchild Semiconductor Corporation
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RD-L026_FL7732 • Rev. 1.1.0
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1. Schematics
Figure 1.
© 2012 Fairchild Semiconductor Corporation
Schematic
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2. Bill of Material
Item
Part
No. Reference
Part number
Qty
Description
Manufacturer
1
BD1
DF06S
1
1.5 A/600V Bridge Diode
Fairchild
Semiconductor
2
CF1
MPX AC275V 104K
1
104/AC275V X-Capacitor
Carli
3
CF2
MPX AC275V 473K
1
473/AC275V X-Capacitor
Carli
4
CS1
C1206C103KDRACTU
1
103/1 kV SMD Capacitor 3216
Kemet
5
CY1
SCFz2E472M10BW
1
472/250 V Y-Capacitor
Samwha
6
Co1, Co2
KMG 470 µF/35 V
2
470 µF/35 V Electrolytic Capacitor
Samyoung
7
C1
MPE 630V104K 14S
1
104/630 V MPE Film Capacitor
Sungho
8
C2
KMG 22 µF/50 V
1
22 µF/35 V Electrolytic Capacitor
Samyoung
9
C3
C0805C104K5RACTU
1
104/50 V SMD Capacitor 2012
Kemet
10
C4
C0805C200J5GACTU
1
200/50 V SMD Capacitor 2012
Kemet
11
C5
C0805C225Z3VACTU
1
225/25 V SMD Capacitor 2012
Kemet
12
DS1
RS1M
1
1000 V/1 A Ultra-Fast Recovery Diode
Fairchild
Semiconductor
13
Do1
ES3D
1
200 V/3 A, Fast Rectifier
Fairchild
Semiconductor
14
D1
1N4003
1
200 V/1 A, General Purpose Rectifier
Fairchild
Semiconductor
15
F1
SS-5-1A
1
250 V/1 A Fuse
Bussmann
16
LF1
R10402KT00
1
4 mH Inductor, 10Ø
Bosung
17
MOV1
SVC 471 D-07A
1
Metal Oxide Varistor
Samwha
18
Q1
FDD5N60NZ
1
600 V/4 A, N-Channel MOSFET
Fairchild
Semiconductor
19
RG1, R6
RC1206JR-0710L
2
10 Ω SMD Resistor 3216
Yageo
20
RS1, RS2
RC1206JR-07100KL
2
100 kΩ SMD Resistor 3216
Yageo
21
Rcs1, Rcs2
RC1206JR-071RL
2
1 Ω SMD Resistor 3216
Yageo
22
Rcs3
RC1206JR-072R4L
1
2.4 Ω SMD Resistor 3216
Yageo
23
Ro1
RC1206JR-0720KL
1
20 KΩ SMD Resistor 3216
Yageo
24
R4
RC1206JR-07150KL
1
150 KΩ SMD Resistor 3216
Yageo
25
R1, R2, R3
RC1206JR-0768KL
3
68 KΩ SMD Resistor 3216
Yageo
26
R5
RC1206JR-0724KL
1
24 KΩ SMD Resistor 3216
Yageo
27
T1
RM8 Core
1
12-Pin, Transformer
TDK
28
U1
FL7732M_F116
1
Main PSR Controller
Fairchild
Semiconductor
© 2012 Fairchild Semiconductor Corporation
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RD-L026_FL7732 • Rev. 1.1.0
www.fairchildsemi.com
3. Transformer
Figure 2.
Transformer Bobbin Structure and Pin Configuration
Figure 3.
Transformer Winding Structure
Table 1.
Winding Specifications
No
Winding
Pin (S → F)
Wire
Turns
Winding Method
1
NP1
12  1
0.25φ
30 Ts
Solenoid Winding
2
3
Insulation : Polyester Tape t = 0.025 mm, 3-Layer
NS
4
5
NP2
20 Ts
Solenoid Winding
12
0.25φ
30 Ts
Solenoid Winding
Insulation : Polyester Tape t = 0.025 mm, 3-Layer
NA
8
Table 2.
0.5φ (TIW)
Insulation : Polyester Tape t = 0.025 mm, 3-Layer
6
7
78
65
0.25φ
15 Ts
Solenoid Winding
Insulation : Polyester Tape t = 0.025 mm, 3-Layer
Electrical Characteristics
Pin
Specification
Remark
Inductance
12–2
750 µH ±10%
60 kHz, 1 V
Leakage
12–2
6 µH
60 kHz, 1 V Short All Output Pins
© 2012 Fairchild Semiconductor Corporation
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RD-L026_FL7732 • Rev. 1.1.0
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4. Performance
Figure 4.
Table 3.
Constant Current Regulation – Measured by E-Load [CR Mode]
Constant Current Regulation by Output Voltage Change (11~28 V)
Input Voltage
Min. Current [mA]
Max. Current [mA]
Tolerance
90 VAC [60 Hz]
656
682
±1.94%
120 VAC [60 Hz]
657
696
±2.88%
140 VAC [60 Hz]
679
696
±1.24%
180 VAC [50 Hz]
685
703
±1.30%
230 VAC [50 Hz]
675
696
±1.53%
265 VAC [50 Hz]
666
681
±1.11%
Table 4.
Constant Current Regulation by Line Voltage Change (90~265 VAC)
Output
Voltage
90 VAC
[60 Hz]
120 VAC
[60 Hz]
140 VAC
[60 Hz]
180 VAC
[50 Hz]
220 VAC
[50 Hz]
265 VAC
[50 Hz]
Tolerance
26 V
678 mA
660 mA
681 mA
700 mA
690 mA
678 mA
±2.94%
24 V
676 mA
659 mA
679 mA
697 mA
684 mA
678 mA
±2.80%
22 V
673 mA
657 mA
683 mA
694 mA
692 mA
681 mA
±2.74%
© 2012 Fairchild Semiconductor Corporation
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RD-L026_FL7732 • Rev. 1.1.0
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Eff. [%]
Figure 5.
Table 5.
System Efficiency (7-LED)
System Efficiency
Input Voltage
Input
Power [W]
Output Current
[A]
Output Voltage
[V]
Output
Power [W]
Efficiency
90 VAC [60 Hz]
18.91
0.678
24.10
16.35
86.45%
120 VAC [60 Hz]
18.02
0.663
24.04
15.94
88.45%
140 VAC [60 Hz]
18.78
0.687
24.27
16.67
88.76%
180 VAC [50 Hz]
19.31
0.704
24.43
17.19
89.03%
220 VAC [50 Hz]
18.99
0.693
24.34
16.86
88.77%
265 VAC [50 Hz]
19.05
0.689
24.28
16.74
87.87%
Figure 6.
© 2012 Fairchild Semiconductor Corporation
Power Factor (PF) & Total Harmonic Distortion (THD)
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Table 6.
Power Factor (PF) & Total Harmonic Distortion (THD)
Input Voltage
Output Current
Output Voltage
Power Factor
THD
90 VAC [60 Hz]
0.678 A
24.10 V
0.98
15.29%
120 VAC [60 Hz]
0.663 A
24.04 V
0.99
14.27%
140 VAC [60 Hz]
0.687 A
24.27 V
0.98
13.61%
180 VAC [50 Hz]
0.704 A
24.43 V
0.98
14.12%
220 VAC [50 Hz]
0.693 A
24.34 V
0.96
17.69%
265 VAC [50 Hz]
0.689 A
24.28 V
0.94
19.01%
5. Related Resources
FL7732 — Single-Stage FPC Primary-Side-Regulation Offline LED Driver
http://www.fairchildsemi.com/referencedesign/
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© 2012 Fairchild Semiconductor Corporation
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RD-L026_FL7732 • Rev. 1.1.0