FL7732 — Single-Stage PFC Primary-Side-Regulation Offline LED Driver
October 2012
FL7732
Single-Stage PFC Primary-Side-Regulation Offline
LED Driver
Features
Cost-Effective Solution: No Input Bulk Capacitor or
Feedback Circuitry
Power Factor Correction
Accurate Constant-Current (CC) Control,
Independent Online Voltage, Output Voltage,
and Magnetizing Inductance Variation
Linear Frequency Control Improves Efficiency and
Simplifies Design
Open-LED Protection
Short-LED Protection
Cycle-by-Cycle Current Limiting
Over-Temperature Protection with Auto Restart
Low Startup Current: 20
μA
Low Operating Current: 5 mA
V
DD
Under-Voltage Lockout (UVLO)
Gate Output Maximum Voltage Clamped at 18 V
SOP-8 Package
Application Voltage Range: 80 V
AC
~ 308 V
AC
Description
This highly integrated PWM controller provides several
features to enhance the performance of low-power
flyback
converters.
The
proprietary
topology,
®
TRUECURRENT enables simplified circuit design for
LED lighting applications.
By using single-stage topology with primary-side
regulation, a LED lighting board can be implemented
with few external components and minimized cost. No
input bulk capacitor or feedback circuitry is required. To
implement good power factor and low THD, constant
on-time control is utilized with an external capacitor
connected to the COMI pin.
Precise constant-current control regulates accurate
output current versus changes in input voltage and
output voltage. The operating frequency is proportionally
adjusted by the output voltage to guarantee DCM
operation with higher efficiency and simpler design.
FL7732 provides open-LED, short-LED, and over-
temperature protection features. The current limit level
is automatically reduced to minimize output current and
protect external components in a short-LED condition.
The FL7732 controller is available in an 8-pin Small-
Outline Package (SOP).
Applications
LED Lighting System
Ordering Information
Part Number
FL7732M_F116
Operating
Temperature Range
-40°C to +125°C
Package
8-Lead, Small Outline Integrated Circuit Package (SOIC)
Packing
Method
Tape & Reel
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
FL7732 — Single-Stage PFC Primary-Side-Regulation Offline LED Driver
Application Diagram
Figure 1.
Typical Application
Internal Block Diagram
Figure 2.
Functional Block Diagram
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
2
FL7732 — Single-Stage PFC Primary-Side-Regulation Offline LED Driver
Marking Information
F:
Fairchild Logo
Z: Plant Code
X: 1-Digit Year Code
Y: 1-Digit Week Code
TT: 2-Digit Die Run Code
T: Package Type (M=SOP)
M: Manufacture Flow Code
Figure 3.
Top Mark
Pin Configuration
Figure 4.
Pin Configuration
Pin Definitions
Pin #
1
2
3
4
5
6
7
8
Name
CS
GATE
GND
VDD
NC
VS
COMI
GND
Description
Current Sense.
This pin connects a current-sense resistor to detect the MOSFET current for
the output-current regulation in constant-current regulation.
PWM Signal Output.
This pin uses the internal totem-pole output driver to drive the power
MOSFET.
Ground
Power Supply.
IC operating current and MOSFET driving current are supplied using this pin.
No Connect
Voltage Sense.
This pin detects the output voltage information and discharge time for
maximum frequency control and constant current regulation. This pin is connected to an
auxiliary winding of the transformer via resistors of the divider.
Constant Current Loop Compensation.
This pin is connected to a capacitor between the
COMI and GND pin for compensation current loop gain.
Ground
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
3
FL7732 — Single-Stage PFC Primary-Side-Regulation Offline LED Driver
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.
The absolute maximum ratings are stress ratings only.
Symbol
V
VDD
V
VS
V
CS
V
COMI
V
GATE
P
D
Θ
JA
Θ
JC
T
J
T
STG
T
L
DC Supply Voltage
(1,2)
VS Pin Voltage
CS Pin Input Voltage
COMI Pin Input Voltage
GATE Pin Input Voltage
Power Dissipation (T
A
<50°C)
Parameter
Min.
-0.3
-0.3
-0.3
-0.3
Max.
30
7
7
7
30
633
158
39
150
Unit
V
V
V
V
V
mW
°C /W
°C /W
°C
°C
°C
Thermal Resistance (Junction-to-Air)
Thermal Resistance (Junction-to-Case)
Maximum Junction Temperature
Storage Temperature Range
Lead Temperature (Soldering 10 s)
-55
150
260
Notes:
1. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device.
2. All voltage values, except differential voltages, are given with respect to the GND pin.
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
4
FL7732 — Single-Stage PFC Primary-Side-Regulation Offline LED Driver
Electrical Characteristics
V
DD
=15 V and T
A
=25°C, unless otherwise specified.
Symbol
V
DD
Section
V
DD-ON
V
DD-OFF
I
DD-OP
I
DD-ST
V
OVP
Gate Section
V
OL
V
OH
I
source
I
sink
t
r
t
f
V
CLAMP
f
MAX-CC
f
MIN-CC
VS
MAX-CC
VS
MIN-CC
t
ON(MAX)
V
RV
V
CCR
t
LEB
t
MIN
t
PD
t
DIS-BNK
I
VS-BNK
Gm
I
COMI-SINK
I
COMI-SOURCE
V
COMI-HGH
V
COMI-LOW
Parameter
Turn-On Threshold Voltage
Turn-Off Threshold Voltage
Operating Current
Startup Current
V
DD
Over-Voltage-Protection Level
Output Voltage Low
Output Voltage High
Peak Sourcing Current
Peak Sinking Current
Rising Time
Falling Time
Output Clamp Voltage
Maximum Frequency in CC
Minimum Frequency in CC
V
S
for Maximum Frequency in CC
V
S
for Minimum Frequency in CC
Maximum Turn-On Time
Reference Voltage
EAI Voltage for CC Regulation
Leading-Edge Blanking Time
Minimum On Time in CC
Propagation Delay to GATE
t
DIS
Blanking Time of VS
VS Current for VS Blanking
Transconductance
COMI Sink Current
COMI Source Current
COMI High Voltage
COMI Low Voltage
Condition
Min.
14.5
6.75
Typ.
16.0
7.75
4
2
Max.
17.5
8.75
5
20
25.0
1.5
Unit
V
V
mA
μA
V
V
V
mA
mA
At Maximum Frequency
C
L
=1 nF
V
DD
=V
DD-ON
– 0.16 V
3
22.0
V
DD
=20 V, I
GATE
=-1 mA
V
DD
=10 V, I
GATE
=+1 mA
V
DD
=10 ~ 20 V
V
DD
=10 ~ 20 V
C
L
=1 nF
C
L
=1 nF
100
20
12
V
DD
=10 V, 20 V
V
DD
=10 V, 20 V
f=f
MAX
-2 kHz
f=f
MIN
+2 kHz
60
21.0
2.25
0.55
12
2.475
V
CS
=0.44 V
V
COMI
=0 V
50
2.38
5
23.5
60
180
150
60
15
65
23.5
2.35
0.85
14
2.500
2.43
300
600
100
1.5
100
85
150
200
100
18
70
26.0
2.45
1.15
16
2.525
2.48
ns
ns
V
kHz
kHz
V
V
μs
V
V
ns
ns
ns
μs
μA
μmho
Oscillator Section
Current-Sense Section
Current-Error-Amplifier Section
V
EAI
=3 V, V
COMI
=5 V
V
EAI
=2 V, V
COMI
=0 V
V
EAI
=2 V
V
EAI
=3 V
25
25
4.9
0.1
38
38
μA
μA
V
V
Continued on the following page…
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
5