User Guide for
FEBFL7730_L20L008B
Dimmable LED Bulb at Low Line
Featured Fairchild Product:
FL7730
Direct questions or comments
about this evaluation board to:
“Worldwide Direct Support”
Fairchild Semiconductor.com
© 2012 Fairchild Semiconductor Corporation
FEBFL7730_L20L008B • Rev.1.1.1
Table of Contents
1. Introduction ............................................................................................................................... 3
1.1.
1.2.
1.3.
General Description........................................................................................................ 3
Features .......................................................................................................................... 3
Internal Block Diagram .................................................................................................. 4
2. General Specifications .............................................................................................................. 5
3. Photographs............................................................................................................................... 6
4. Printed Circuit Board ................................................................................................................ 7
5. Schematic .................................................................................................................................. 8
6. Bill of Materials ........................................................................................................................ 9
7. Transformer and Winding Specifications ............................................................................... 11
8. Performance of Evaluation Board ........................................................................................... 12
8.1.
8.2.
8.3.
8.4.
8.5.
8.6.
8.7.
8.8.
8.9.
Startup .......................................................................................................................... 12
Operation Waveforms .................................................................................................. 12
Constant Current Regulation ........................................................................................ 13
Open/Short-LED Protections ....................................................................................... 14
Dimming Operation...................................................................................................... 15
System Efficiency ........................................................................................................ 18
Power Factor and Total Harmonic Distortion .............................................................. 19
Operating Temperature ................................................................................................ 21
Electromagnetic Interference (EMI) ............................................................................ 22
9. Revision History ..................................................................................................................... 23
© 2012 Fairchild Semiconductor Corporation
2
FEBFL7730_L20L008B • Rev.1.1.1
This FEBFL7730_L20L008B Evalution Board can be identified by the silkscreen
marking FL7730 Low Line on the top side of the pcb. This user guide supports the
evaluation board for the FL7730, FEBFL7730_L20L008B. This kit supersedes the
FEBFL7730_L20L008A. The revised kit incorporates the next generation FL7730, which
is redesigned for improved dimming performance. It should be used in conjunction with
the FL7730 datasheet as well as Fairchild’s application notes and technical support team.
Please visit Fairchild’s website at
www.fairchildsemi.com
or the evaluation board page
http://www.fairchildsemi.com/products/evaluationboards/.
1. Introduction
This document describes the proposed solution for low-line voltage LED ballast using the
FL7730 Primary-Side Regulator (PSR) single-stage controller. The input voltage range is
90V
RMS
– 140V
RMS
and there is one DC output with a constant current of 380mA at
22V
MAX
. This document contains general description of FL7730, the power supply
specification, schematic, bill of materials, and the typical operating characteristics.
1.1.
General Description
The FL7730 is an active Power Factor Correction (PFC) controller using single-stage
flyback topology. Dimming control with no flicker is implemented by an analog sensing
method. Primary-side regulation and single-stage topology reduce external components
such as input bulk capacitor and feedback circuitry and minimize cost. To improve good
power factor and Total Harmonic Distortion (THD), constant on-time control is utilized
with 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 higher efficiency. FL7730 provides protections such as open-LED,
short-LED, and over-temperature protection.
1.2.
Features
Compatible with Traditional TRIAC Control
Cost-Effective Solution without Input Bulk Capacitor and Feedback Circuitry
Power Factor Correction (PFC)
Accurate Constant-Current (CC) Control
Line Voltage Compensation for 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 with Auto Restart
Low Startup Current: 20μA
Low Operating Current: 5mA
V
DD
Under-Voltage Lockout (UVLO)
Gate Output Maximum Voltage Clamped at 18V
SOP-8 Package Available
3
FEBFL7730_L20L008B • Rev.1.1.1
© 2012 Fairchild Semiconductor Corporation
1.3.
Internal Block Diagram
Figure 1.
Internal Block Diagram
© 2012 Fairchild Semiconductor Corporation
4
FEBFL7730_L20L008B • Rev.1.1.1
2. General Specifications
All data in Table 1 was measured at an ambient temperature of 25°C.
Table 1.
Summary of Features and Performance for LED Lighting Bulb
Symbol
V
IN
,
MIN
Input Voltage
V
IN
,
MAX
V
IN,NOMINAL
Input Frequency
f
IN
V
OUT,MIN
V
OUT,MAX
V
OUT,NOMINAL
Output Voltage
Current
I
OUT
,
NOMINAL
I
OUT,RIPPLE
CC Deviation
Description
Value
90V
140V
110~120V
50-60Hz
10V
28V
22V
380mA
±65mA
<±3.9%
<±2.1%
Comments
Minimum Input Voltage
Maximum Input Voltage
Nominal Input Voltage
Line Frequency
Minimum Output Voltage
Maximum Output Voltage
Nominal Output Voltage
Nominal Output Current
Output Current Ripple
Line Input Voltage Change:90~140V
AC
Output Voltage Change:10~28V
Note: No Dimmer Connected
Eff
90VAC
Efficiency
Eff
110VAC
Eff
120VAC
Eff
140VAC
80.7%
82.2%
82.5%
82.9%
Efficiency at 90V
AC
Line Input Voltage
Efficiency at 110V
AC
Line Input Voltage
Efficiency at 120V
AC
Line Input Voltage
Efficiency at 140V
AC
Line Input Voltage
Note: No Dimmer Connected
PF / THD
90VAC
PF / THD
PF / THD
110VAC
PF / THD
120VAC
PF / THD
140VAC
0.98 / 7.4%
0.96 / 9.5%
PF / THD at 90V
AC
Line Input Voltage
PF / THD at 110V
AC
Line Input Voltage
0.95 / 10.4% PF / THD at 120V
AC
Line Input Voltage
0.91 / 12.4% PF / THD at 140 V
AC
Line Input Voltage
Note: Open-Frame Condition (T
A
=25°C)
T
FL7730
T
MOSFET
Temperature
T
DIODE
T
TRANSFORMER
T
DAMPER
T
STR.RESISTOR
50ºC
53ºC
47ºC
52ºC
57ºC
56ºC
FL7730 Temperature
Primary MOSFET Temperature
Secondary Diode Temperature
Transformer Temperature
Active Damper Temperature
Startup Resistor Temperature
© 2012 Fairchild Semiconductor Corporation
5
FEBFL7730_L20L008B • Rev.1.1.1