FL7732MF116 [FAIRCHILD]
Single-Stage PFC Primary-Side-Regulation Offline LED Driver; 单级PFC的初级侧调节离线LED驱动器
| 型号： | FL7732MF116 |
| 厂家： | 
FAIRCHILD SEMICONDUCTOR |
| 描述： | Single-Stage PFC Primary-Side-Regulation Offline LED Driver |
| 文件： | 总13页 (文件大小：1519K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
October 2012
FL7732
Single-Stage PFC Primary-Side-Regulation Offline
LED Driver
Description
Features
This highly integrated PWM controller provides several
features to enhance the performance of low-power
.
Cost-Effective Solution: No Input Bulk Capacitor or
Feedback Circuitry
flyback
converters.
The
proprietary
topology,
TRUECURRENT® enables simplified circuit design for
LED lighting applications.
.
.
Power Factor Correction
Accurate Constant-Current (CC) Control,
Independent Online Voltage, Output Voltage,
and Magnetizing Inductance Variation
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.
.
Linear Frequency Control Improves Efficiency and
Simplifies Design
.
.
.
.
.
.
.
.
.
.
Open-LED Protection
Short-LED Protection
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.
Cycle-by-Cycle Current Limiting
Over-Temperature Protection with Auto Restart
Low Startup Current: 20 μA
Low Operating Current: 5 mA
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.
VDD Under-Voltage Lockout (UVLO)
Gate Output Maximum Voltage Clamped at 18 V
SOP-8 Package
The FL7732 controller is available in an 8-pin Small-
Outline Package (SOP).
Application Voltage Range: 80 VAC ~ 308 VAC
Applications
.
LED Lighting System
Ordering Information
Operating
Temperature Range
Packing
Part Number
Package
Method
FL7732M_F116
-40°C to +125°C
8-Lead, Small Outline Integrated Circuit Package (SOIC) Tape & Reel
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
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
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
Description
Pin Definitions
Pin #
Name
Current Sense. This pin connects a current-sense resistor to detect the MOSFET current for
the output-current regulation in constant-current regulation.
1
CS
PWM Signal Output. This pin uses the internal totem-pole output driver to drive the power
MOSFET.
2
GATE
3
4
5
GND
VDD
NC
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.
6
VS
Constant Current Loop Compensation. This pin is connected to a capacitor between the
COMI and GND pin for compensation current loop gain.
7
8
COMI
GND
Ground
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
3
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
VVDD
VVS
Parameter
Min.
Max.
30
Unit
V
DC Supply Voltage(1,2)
VS Pin Voltage
-0.3
-0.3
-0.3
-0.3
7
V
VCS
CS Pin Input Voltage
COMI Pin Input Voltage
GATE Pin Input Voltage
Power Dissipation (TA＜50°C)
7
V
VCOMI
VGATE
PD
7
V
30
V
633
158
39
mW
°C /W
°C /W
°C
Thermal Resistance (Junction-to-Air)
Thermal Resistance (Junction-to-Case)
Maximum Junction Temperature
Storage Temperature Range
ΘJA
ΘJC
TJ
150
150
260
TSTG
TL
-55
°C
Lead Temperature (Soldering 10 s)
°C
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
Electrical Characteristics
VDD=15 V and TA=25°C, unless otherwise specified.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
VDD Section
VDD-ON
Turn-On Threshold Voltage
Turn-Off Threshold Voltage
14.5
6.75
16.0
7.75
17.5
8.75
V
V
VDD-OFF
At Maximum Frequency
CL=1 nF
IDD-OP
Operating Current
3
4
5
mA
IDD-ST
Startup Current
VDD=VDD-ON – 0.16 V
2
20
μA
VOVP
VDD Over-Voltage-Protection Level
22.0
23.5
25.0
V
Gate Section
VOL
VOH
Isource
Isink
Output Voltage Low
Output Voltage High
Peak Sourcing Current
Peak Sinking Current
Rising Time
VDD=20 V, IGATE=-1 mA
VDD=10 V, IGATE=+1 mA
VDD=10 ~ 20 V
VDD=10 ~ 20 V
CL=1 nF
1.5
V
V
5
60
180
150
60
mA
mA
ns
ns
V
tr
100
20
200
100
18
tf
Falling Time
CL=1 nF
VCLAMP
Output Clamp Voltage
12
15
Oscillator Section
fMAX-CC Maximum Frequency in CC
fMIN-CC
VDD=10 V, 20 V
VDD=10 V, 20 V
f=fMAX-2 kHz
60
65
70
kHz
kHz
V
Minimum Frequency in CC
21.0
2.25
0.55
12
23.5
2.35
0.85
14
26.0
2.45
1.15
16
VSMAX-CC
VSMIN-CC
tON(MAX)
VS for Maximum Frequency in CC
VS for Minimum Frequency in CC
Maximum Turn-On Time
f=fMIN +2 kHz
V
μs
Current-Sense Section
VRV
VCCR
tLEB
Reference Voltage
2.475
2.38
2.500
2.43
300
600
100
1.5
2.525
2.48
V
V
EAI Voltage for CC Regulation
Leading-Edge Blanking Time
Minimum On Time in CC
VCS=0.44 V
ns
ns
ns
μs
μA
tMIN
VCOMI=0 V
tPD
Propagation Delay to GATE
tDIS Blanking Time of VS
50
150
tDIS-BNK
IVS-BNK
VS Current for VS Blanking
100
Current-Error-Amplifier Section
Gm
Transconductance
COMI Sink Current
85
μmho
μA
μA
V
ICOMI-SINK
25
25
38
38
VEAI=3 V, VCOMI=5 V
VEAI=2 V, VCOMI=0 V
VEAI=2 V
ICOMI-SOURCE COMI Source Current
VCOMI-HGH COMI High Voltage
VCOMI-LOW COMI Low Voltage
4.9
VEAI=3 V
0.1
V
Continued on the following page…
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
5
Electrical Characteristics (Continued)
VDD=15 V and TA=25°C, unless otherwise specified.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
Over-Current Protection Section
VOCP
VCS Threshold Voltage for OCP
0.60
0.13
0.67
0.18
0.74
0.23
V
V
VLowOCP
VCS Threshold Voltage for Low OCP
VS Threshold Voltage to Enable Low
OCP Level
VLowOCP-EN
VLowOCP-DIS
0.4
0.6
V
V
VS Threshold Voltage to Disable Low
OCP Level
Over-Temperature Protection Section
TOTP
Threshold Temperature for OTP(3)
140
150
10
160
oC
oC
Restart Junction Temperature
Hysteresis
TOTP-HYS
Note:
3. If over-temperature protection is activated, the power system enters Auto-Recovery Mode and output is disabled.
Device operation above the maximum junction temperature is NOT guaranteed. OTP is guaranteed by design.
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
6
Typical Performance Characteristics
1.5
1.3
1.1
0.9
0.7
0.5
1.5
1.3
1.1
0.9
0.7
0.5
-40
-40
-40
-30
-15
0
0
0
25
50
75
85
100 125
-40
-40
-40
-30
-15
0
0
0
25
50
75
85
100 125
Temp [°C]
Temp [°C]
Figure 5.
VDD-ON vs. Temperature
Figure 6.
VDD-OFF vs. Temperature
1.5
1.3
1.1
0.9
0.7
0.5
1.5
1.3
1.1
0.9
0.7
0.5
-30
-15
25
50
75
85
100 125
-30
-15
25
50
75
85
100 125
Temp [°C]
Temp [°C]
Figure 7.
IDD-OP vs. Temperature
Figure 8.
VOVP vs. Temperature
1.5
1.3
1.1
0.9
0.7
0.5
1.5
1.3
1.1
0.9
0.7
0.5
-30
-15
25
50
75
85
100 125
-30
-15
25
50
75
85
100 125
Temp [°C]
Temp [°C]
Figure 9.
fMAX_CC vs. Temperature
Figure 10. fMIN_CC vs. Temperature
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
7
Typical Performance Characteristics (Continued)
1.5
1.3
1.1
0.9
0.7
0.5
1.5
1.3
1.1
0.9
0.7
0.5
-40
-30
-15
0
25
50
75
85
100 125
-40
-30
-15
0
25
50
75
85
100 125
Temp [°C]
Temp [°C]
Figure 11. VCCR vs. Temperature
Figure 12. VVVR vs. Temperature
1.5
1.3
1.1
0.9
0.7
0.5
1.5
1.3
1.1
0.9
0.7
0.5
-40
-30
-15
0
25
50
75
85
100 125
-40
-30
-15
0
25
50
75
85
100 125
Temp [°C]
Temp [°C]
Figure 13. VOCP vs. Temperature
Figure 14. VOCP_Low vs. Temperature
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
8
Functional Description
FL7732 is AC-DC PWM controller for LED lighting
applications. TRUECURRENT® techniques regulate
accurate LED current independent or input voltage,
output voltage, and magnetizing inductance variations.
The linear frequency control in the oscillator reduces
conduction loss and maintains DCM operation in the
wide range of output voltage, which implements high
TRUECURRENT® technique, constant-current output
can be precisely controlled.
PFC and THD
In a conventional boost converter, Boundary Conduction
Mode (BCM) is generally used to keep input current in-
phase with input voltage for PF and THD. In
flyback/buck boost topology, constant turn-on time and
constant frequency in Discontinuous Conduction Mode
(DCM) can implement high PF and low THD, as shown
in Figure 16. Constant turn-on time is maintained by
the internal error amplifier and a large external
capacitor (typically over 1 µF) at the COMI pin.
Constant frequency and DCM operation are managed
by linear frequency control.
power factor correction in
a single-stage flyback
topology. A variety of protections, such as short/open-
LED protection, over-temperature protection, and cycle-
by-cycle current limitation stabilize system operation
and protect external components.
Startup
Powering at startup is slow due to the low feedback loop
bandwidth in PFC converter. To boost powering during
startup, an internal oscillator counts 12 ms to define
Startup Mode. During Startup Mode, turn-on time is
determined by Current-Mode control with a 0.2 VCS
voltage limit and transconductance becomes 14 times
larger, as shown in Figure 15. After startup, turn-on time
is controlled by Voltage Mode using COMI voltage and
error amplifier transconductance is reduced to 85 μmho.
Figure 16. Input Current and Switching
Linear Frequency Control
As mentioned above, DCM should be guaranteed for
high power factor in flyback topology. To maintain DCM
across the wide range of output voltage, frequency is
linearly adjusted by output voltage in linear frequency
control. Output voltage is detected by the auxiliary
winding and the resistive divider connected to the VS
pin, as shown in Figure 17.
Figure 15. Startup Sequence
Constant-Current Regulation
The output current can be estimated using the peak
drain current and inductor current discharge time since
output current is same as the average of the diode
current in steady state. The peak value of the drain
current is determined by the CS pin and the inductor
discharge time (tDIS) is sensed by tDIS detector. By using
three points of information (peak drain current, inductor
discharging time, and operating switching period);
TRUECURRENT® calculation block estimates output
current. The output of the calculation is compared with
an internal precise reference to generate an error
voltage (VCOMI), which determines turn-on time in
Voltage-Mode control. With Fairchild’s innovative
Figure 17. Linear Frequency Control
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
9
When output voltage decreases, secondary diode
conduction time is increased and the linear frequency
control lengthens the switching period, which retains
DCM operation in the wide output voltage range, as
shown in Figure 18. The frequency control lowers the
primary rms current with better power efficiency in the
full-load condition.
Figure 20 shows operational waveforms in short-LED
condition. Output voltage is quickly lowered to 0V right
after a short-LED event. Then the reflected auxiliary
voltage is also 0 V, making VS less than 0.4 V. 0.2 V
OCP level limits primary-side current and VDD hiccups
up and down between UVLO hysteresis.
m
t
t
DIS
3
4
m
n
VO
L
4
3
4
3
t
t
DIS
3
5
L
n
V
O
m
5
3
5
3
t
t
DIS
Figure 20. Waveforms in Short-LED Condition
Figure 18. Primary and Secondary Current
Open-LED Protection
BCM Control
FL7732 protects external components, such as diode
and capacitor, at secondary side in open-LED condition.
During switch-off, the VDD capacitor is charged up to the
auxiliary winding voltage, which is applied as the
reflected output voltage. Because the VDD voltage has
output voltage information, the internal voltage
comparator on the VDD pin can trigger output Over-
Voltage Protection (OVP), as shown in Figure 21. When
at least one LED is open-circuited, output load
impedance becomes very high and output capacitor is
quickly charged up to VOVP x NS / NA Then switching is
shut down and the VDD block goes into Hiccup Mode
until the open-LED condition is removed, as shown
in Figure 22.
The end of secondary diode conduction time is possibly
over a switching period set by linear frequency control.
In this case, FL7732 doesn’t allow CCM and the
operation mode changes from DCM to BCM. Therefore,
magnetizing inductance can be largely designed to add
BCM for better efficiency if PF and THD meet
specification with enough margin.
Short-LED Protection
In case of
a short-LED condition, the switching
MOSFET and secondary diode are stressed by the high
powering current. However, FL7732 changes the OCP
level in a short-LED condition. When VS voltage is lower
than 0.4 V, OCP level becomes 0.2 V from 0.7 V, as
shown in Figure 19, so powering is limited and external
components current stress is reduced.
Figure 19. Internal OCP Block
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
10
Under-Voltage Lockout (UVLO)
The turn-on and turn-off thresholds are fixed internally at
16 V and 7.5 V, respectively. During startup, the VDD
capacitor must be charged to 16 V through the startup
resistor to enable the FL7732. The VDD capacitor
continues to supply VDD until power can be delivered
from the auxiliary winding of the main transformer.
VDD must not drop below 7.5 V during this startup
process. This UVLO hysteresis window ensures that the
VDD capacitor is adequate to supply VDD during startup.
Over-Temperature Protection (OTP)
The FL7732 has a built-in temperature-sensing circuit to
shut down PWM output if the junction temperature
exceeds 150°C. While PWM output is shut down, the
VDD voltage gradually drops to the UVLO voltage. Some
of the internal circuits are shut down and VDD gradually
starts increasing again. When VDD reaches 16 V, all the
internal circuits start operating. If the junction
temperature is still higher than 140°C, the PWM
controller is shut down immediately.
Figure 21. Internal OVP Block
Figure 22. Waveforms in Open-LED Condition
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
11
Physical Dimensions
5.00
4.80
A
0.65
3.81
8
5
B
1.75
6.20
5.80
4.00
3.80
5.60
1
4
PIN ONE
INDICATOR
1.27
1.27
(0.33)
0.25
C B A
LAND PATTERN RECOMMENDATION
SEE DETAIL A
0.25
0.10
0.25
0.19
C
1.75 MAX
0.51
0.33
0.10 C
x 45°
OPTION A - BEVEL EDGE
0.50
0.25
R0.10
R0.10
GAGE PLANE
OPTION B - NO BEVEL EDGE
0.36
NOTES: UNLESS OTHERWISE SPECIFIED
8°
0°
0.90
0.40
A) THIS PACKAGE CONFORMS TO JEDEC
MS-012, VARIATION AA, ISSUE C,
B) ALL DIMENSIONS ARE IN MILLIMETERS.
C) DIMENSIONS DO NOT INCLUDE MOLD
FLASH OR BURRS.
SEATING PLANE
(1.04)
D) LANDPATTERN STANDARD: SOIC127P600X175-8M.
E) DRAWING FILENAME: M08AREV13
DETAIL A
SCALE: 2:1
Figure 23. 8-Lead, Small Outline Integrated Circuit Package (SOIC)
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner
without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or
obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the
warranty therein, which covers Fairchild products.
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:
http://www.fairchildsemi.com/packaging/.
© 2012 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
11
© 2011 Fairchild Semiconductor Corporation
FL7732 • Rev. 1.0.6
www.fairchildsemi.com
13
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