User Guide for
FEB-L027
Evaluation Board
Reference Design Report for a 17.5W T8
LED Lamp Using FL7732
Featured Fairchild Product:
FL7732
Direct questions or comments
about this evaluation board to:
“Worldwide Direct Support”
Fairchild Semiconductor.com
© 2012 Fairchild Semiconductor Corporation 1 FEB-L027_FL7732 • Rev. 1.0.0
Table of Contents
1. Introduction ............................................................................................................................... 3
1.1. General Description ........................................................................................................... 3
1.2. Features ............................................................................................................................. 3
1.3. Internal Block Diagram ..................................................................................................... 4
2. General Specifications for Evaluation Board ........................................................................... 5
3. Evaluation Board ...................................................................................................................... 6
4. Schematic .................................................................................................................................. 7
5. Bill of Materials ........................................................................................................................ 8
6. Transformer Design ................................................................................................................ 10
7. Electromagnetic Interference (EMI) Inductor (L1 & L2) Design .......................................... 11
8. Performance of Evaluation Board ........................................................................................... 12
8.1. Test Condition & Equipments ......................................................................................... 12
8.2. Startup ............................................................................................................................. 13
8.3. Operation Waveforms ..................................................................................................... 14
8.4. Constant-Current Regulation ........................................................................................... 15
8.5. Short-LED/ Open-LED Protections ................................................................................ 16
8.6. System Efficiency ............................................................................................................ 17
8.7. Power Factor & Total Harmonic Distortion .................................................................... 18
8.8. Operating Temperature .................................................................................................... 19
8.9. Electromagnetic Interference (EMI) ............................................................................... 20
9. Revision History ..................................................................................................................... 21
© 2012 Fairchild Semiconductor Corporation 2 FEB-L027_FL7732 • Rev. 1.0.0
The following user guide supports the evaluation 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
1. Introduction
This document describes the proposed solution for a universal line voltage T8 LED lamp
using the FL7732 Primary Side Regulator (PSR) single-stage controller. The input
voltage range is 90V
500mA at 35V
supply specification, schematic, bill of materials, and the typical operating characteristics.
1.1. General Description
The FL7732 is an active Power Factor Correction (PFC) controller using single-stage
flyback topology. Primary-side regulation and single-stage topology reduce external
components, such as input bulk capacitor and feedback circuitry, and minimize cost. To
improve power factor and Total Harmonic Discharge (THD), constant on-time control is
utilized with an internal error amplifier and a low-bandwidth compensator. Precise
constant-current control regulates accurate output current, independent of input voltage
and output voltage. Operating frequency is proportionally changed by output voltage to
guarantee DCM operation with high efficiency and simple design. FL7732 provides
open-LED, short-LED, and over-temperature protections.
– 265V
RMS
. This document contains general description of FL7732, the power
MAX
. There is one DC output with a constant current of
RMS
.
1.2. Features
Cost-Effective Solution: No Input Bulk Capacitor and Feedback Circuitry
Power Factor Correction (PFC)
Accurate Constant-Current (CC) Control
Linear Frequency Control for Better Efficiency and Simpler Design
Open-LED Protection
Short-LED Protection
Cycle-by-Cycle Current Limiting
Over-Temperature Protection (OTP) with Auto Restart
Low Startup Current: 20 μA
Low Operating Current: 5mA
V
Under-Voltage Lockout (UVLO)
DD
Gate Output Maximum Voltage Clamped at 18V
SOP-8 Package
© 2012 Fairchild Semiconductor Corporation 3 FEB-L027_FL7732 • Rev. 1.0.0
1.3. Internal Block Diagram
Figure 1. Block Diagram of FL7732
© 2012 Fairchild Semiconductor Corporation 4 FEB-L027_FL7732 • Rev. 1.0.0
2. General Specifications for Evaluation Board
Table 1. Evaluation Board Specifications for LED Lighting Lamp
Description Symbol Value Comments
V
90V Minimum Input Voltage
IN.MIN
V
Input
Output
Efficiency
PF/THD
Temperature
Voltage
Frequency
Voltage
Current
FL7732
Primary
MOSFET
Secondary
Diode
V
V
V
OUT.NOMINAL
I
OUT.NOMINAL
CC Deviation
Eff
Eff
Eff
Eff
Eff
PF / THD
PF / THD
PF / THD
PF / THD
PF / THD
PF / THD
265V Maximum Input Voltage
IN.MAX
IN.NOMINAL
110V / 220V Nominal Input Voltage
fIN 60Hz / 50Hz Line Frequency
V
17.5V Minimum Output Voltage
OUT.MIN
37V Maximum Output Voltage
OUT.MAX
35V Nominal Output Voltage
500mA Nominal Output Current
< ±2.59% Line Input Voltage Change: 90~265V
< ±1.82% Output Voltage Change: 17.5~35V
Eff
90VAC
120VAC
140VAC
180VAC
220VAC
89.14% Efficiency at 265VAC Line Input Voltage
265VAC
90VAC
120VAC
140VAC
180VAC
220VAC
265VAC
T
44.8ºC
FL7732
T
59.6ºC Primary MOSFET Temperature
MOSFET
T
66.6ºC Secondary Diode Temperature
DIODE
87.02% Efficiency at 90VAC Line Input Voltage
88.67% Efficiency at 120VAC Line Input Voltage
89.22% Efficiency at 140VAC Line Input Voltage
89.60% Efficiency at 180VAC Line Input Voltage
89.54% Efficiency at 220VAC Line Input Voltage
0.999 / 7.38% PF / THD at 90VAC Line Input Voltage
0.997 / 8.98% PF / THD at 120VAC Line Input Voltage
0.995 / 11.02% PF / THD at 140VAC Line Input Voltage
0.990 / 13.87% PF / THD at 180VAC Line Input Voltage
0.978 / 16.63% PF / THD at 220VAC Line Input Voltage
0.959 / 18.75% PF / THD at 265VAC Line Input Voltage
Open-Frame Condition
(T
= 25ºC) Temperature
A
AC
Transformer
T
TRANSFORMER
64.5ºC Transformer Temperature
All data was measured with the board enclosed in a case and external temperature around
25C°.
© 2012 Fairchild Semiconductor Corporation 5 FEB-L027_FL7732 • Rev. 1.0.0
3. Evaluation Board
Dimensions: 297.81 (L) × 17.14 (W) × 11.00 (H) [mm]
Figure 2. Top / Bottom of Evaluation Board Figure 3. PCB Pattern Top / Bottom of
Evaluation Board
© 2012 Fairchild Semiconductor Corporation 6 FEB-L027_FL7732 • Rev. 1.0.0
4. Schematic
250V/1A
LN
F
1
10D471
RV
1
20mH
R
1
L
1MΩ R
CX
1
1
47nF/450V
2
1MΩ
1N4007
40mH
1N4007
L
2
D
2
1N4007
D
3
D
1
1N4007
D
4
100pF
1.5Ω
1.5Ω
1Ω
UF4007
R
4
100K
47nF/450V
C
1
47nF/450V
100KΩ
D
3.3nF
5
1mH
L
C
2
R
3
750KΩ
C
3
3
R
5
750KΩ
R
6
750KΩ
R
7
N1
2.2uF
C
8
8
GND
VS
R
11
10Ω
R
13
NC
GATE
2
150kΩ
R
9
765
COMI
VDD
4
D
7
1N4148
FL7732
U1
C
5
104
22µF/35V
FDPF5N60NZ
Q
1
UF4007
C
4
4.7Ω
D
6
R
8
N2
3
GND
CS
1
C
10
R
0
12
R
14
10KΩ
R
15
R
16
18kΩ
R
10
T1
10pF
C
7
2.2nF
C
Y1
470µF/50V
470µF/50V
N3
D
9
UF4007
D
8
C
12
C
13
470µF/50V
47kΩ
R
19
UF4007
5µH/jump
L
C
14
4
40V/0.5A
V
O
C
11
100pF
R
R
17
18
20Ω
20Ω
Figure 4. Evaluation Board Schematic
© 2012 Fairchild Semiconductor Corporation 7 FEB-L027_FL7732 • Rev. 1.0.0