2024年3月23日发(作者：公良文静)
LT3799-1
Offline Isolated Flyback
LED Controller with Active PFC
FEATURES
Isolated PFC LED Driver with Minimum Number of
External Components
n
V and V
INOUT
Limited Only by External Components
n
Active Power Factor Correction (Typical PFC > 0.97)
n
Low Harmonic Content
n
No Opto-Coupler Required
n
Accurate Regulated LED Current (±5% Typical)
n
Open LED and Shorted LED Protection
n
Thermally Enhanced 16-Lead MSOP Package
n
DESCRIPTION
The LT
®
3799-1 is an isolated flyback controller with power
factor correction specifically designed for driving LEDs.
The controller operates using critical conduction mode
allowing the use of a small transformer. Using a novel
current sensing scheme, the controller is able to deliver a
well regulated current to the secondary side without using
an opto-coupler. A strong gate driver is included to drive
an external high voltage MOSFET. Utilizing an onboard
multiplier, the LT3799-1 typically achieves power factors
of 0.97. The FAULT pin provides notification of open and
short LED conditions. The LT3799-1 offers improved line
regulation over the LT3799, but is not designed for use
with a TRIAC dimmer.
The LT3799-1 uses a micropower hysteretic start-up to
efficiently operate at offline input voltages, with a third
winding to provide power to the part. An internal LDO
provides a well regulated supply for the part’s internal
circuitry and gate driver.
APPLICATIONS
Offline 4W to 100W+ LED Applications
n
High DC V LED Applications
IN
n
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Patents pending.
TYPICAL APPLICATION
20W LED Driver
1.20
1.15
LED Current vs Input Voltage
90V
TO 150V
AC
100k
0.22μF
499k
499k
V
IN
V
IN_SENSE
6.34k
V
REF
100k
32.4k
40.2k
CTRL3
CTRL2
100k
NTC
15.8k
FAULT
CTRL1
LT3799-1
100k
20Ω
4:1:1
I
L
E
D
(
A
)
1.10
1.05
4.7pF
10μ
F
2k
DCM
FB
4.99k
100k
170V
560μ
F
×
2
1.00
0.95
0.90
0.85
0.80
1A
GATE
SENSE
INTV
CC
20Ω
33V
20W
LED
POWER
90
1
V
IN
(V
AC
)
140
150
37991 TA01b
0.05Ω
4.7μF
GND
FAULT
CT
COMP
+
0.1μF
COMP
–
2.2nF
37991 TA01a
0.1μF
37991f
/
1
LT3799-1
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
CTRL1
CTRL2
CTRL3
V
REF
FAULT
CT
COMP
+
COMP
–
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
IN_SENSE
SENSE
GATE
INTV
CC
NC
V
IN
DCM
FB
V
IN
, .32V
GATE, INTV
CC
...........................................................12V
CTRL1, CTRL2, CTRL3, V
IN_SENSE
, COMP
–
................4V
FB, CT, V
REF,
COMP
+
, ...................................................3V
SENSE ......................................................................0.4V
DCM .......................................................................±3mA
Maximum Junction Temperature ..........................125°C
Operating Temperature Range (Note 2)
LT3799-1E ..........................................–40°C to 125°C
LT3799-1I ...........................................–40°C to 125°C
Storage Temperature Range ..................–65°C to 150°C
17
GND
MSE PACKAGE
16-LEAD PLASTIC MSOP
θ
JA
= 50°C/W, θ
JC
= 10°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT3799EMSE-1#PBF
LT3799IMSE-1#PBF
TAPE AND REEL
LT3799EMSE-1#TRPBF
LT3799IMSE-1#TRPBF
PART MARKING*
37991
37991
PACKAGE DESCRIPTION
16-Lead Plastic MSOPE
16-Lead Plastic MSOPE
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: /leadfree/
For more information on tape and reel specifications, go to: /tapeandreel/
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 18V, INTV
CC
= 11V, unless otherwise noted.
PARAMETER
V
IN
Turn-On Voltage
V
IN
Turn-Off Voltage
V
IN
Hysteresis
V
IN
Shunt Regulator Voltage
V
IN
Shunt Regulator Current Limit
V
IN
Quiescent Current
INTV
CC
Quiescent Current
V
IN_SENSE
Linear Range
V
REF
Voltage
Error Amplifier Voltage Gain
Error Amplifier Transconductance
0μA Load
200μA Load
ΔV
COMP
+
/ΔV
COMP
–
, CTRL1 = 1V, CTRL2 = 2V, CTRL3 = 2V
ΔI = 5μA
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONSMIN
22.2
11.8
TYP
23
12.3
10.7
25.0
MAX
24.2
13.0
UNITS
V
V
V
V
mA
V
TURNON
– V
TURNOFF
I = 1mA
15
Before Turn-On
After Turn-On
Before Turn-On
After Turn-On
55
12
1.5
0
1.97
1.95
65
70
16
2.1
2
1.98
100
50
75
20
2.6
1.3
2.03
2.03
μA
μA
μA
mA
V
V
V
V/V
μmhos
37991f
/
2
2024年3月23日发(作者：公良文静)
LT3799-1
Offline Isolated Flyback
LED Controller with Active PFC
FEATURES
Isolated PFC LED Driver with Minimum Number of
External Components
n
V and V
INOUT
Limited Only by External Components
n
Active Power Factor Correction (Typical PFC > 0.97)
n
Low Harmonic Content
n
No Opto-Coupler Required
n
Accurate Regulated LED Current (±5% Typical)
n
Open LED and Shorted LED Protection
n
Thermally Enhanced 16-Lead MSOP Package
n
DESCRIPTION
The LT
®
3799-1 is an isolated flyback controller with power
factor correction specifically designed for driving LEDs.
The controller operates using critical conduction mode
allowing the use of a small transformer. Using a novel
current sensing scheme, the controller is able to deliver a
well regulated current to the secondary side without using
an opto-coupler. A strong gate driver is included to drive
an external high voltage MOSFET. Utilizing an onboard
multiplier, the LT3799-1 typically achieves power factors
of 0.97. The FAULT pin provides notification of open and
short LED conditions. The LT3799-1 offers improved line
regulation over the LT3799, but is not designed for use
with a TRIAC dimmer.
The LT3799-1 uses a micropower hysteretic start-up to
efficiently operate at offline input voltages, with a third
winding to provide power to the part. An internal LDO
provides a well regulated supply for the part’s internal
circuitry and gate driver.
APPLICATIONS
Offline 4W to 100W+ LED Applications
n
High DC V LED Applications
IN
n
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Patents pending.
TYPICAL APPLICATION
20W LED Driver
1.20
1.15
LED Current vs Input Voltage
90V
TO 150V
AC
100k
0.22μF
499k
499k
V
IN
V
IN_SENSE
6.34k
V
REF
100k
32.4k
40.2k
CTRL3
CTRL2
100k
NTC
15.8k
FAULT
CTRL1
LT3799-1
100k
20Ω
4:1:1
I
L
E
D
(
A
)
1.10
1.05
4.7pF
10μ
F
2k
DCM
FB
4.99k
100k
170V
560μ
F
×
2
1.00
0.95
0.90
0.85
0.80
1A
GATE
SENSE
INTV
CC
20Ω
33V
20W
LED
POWER
90
1
V
IN
(V
AC
)
140
150
37991 TA01b
0.05Ω
4.7μF
GND
FAULT
CT
COMP
+
0.1μF
COMP
–
2.2nF
37991 TA01a
0.1μF
37991f
/
1
LT3799-1
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
CTRL1
CTRL2
CTRL3
V
REF
FAULT
CT
COMP
+
COMP
–
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
IN_SENSE
SENSE
GATE
INTV
CC
NC
V
IN
DCM
FB
V
IN
, .32V
GATE, INTV
CC
...........................................................12V
CTRL1, CTRL2, CTRL3, V
IN_SENSE
, COMP
–
................4V
FB, CT, V
REF,
COMP
+
, ...................................................3V
SENSE ......................................................................0.4V
DCM .......................................................................±3mA
Maximum Junction Temperature ..........................125°C
Operating Temperature Range (Note 2)
LT3799-1E ..........................................–40°C to 125°C
LT3799-1I ...........................................–40°C to 125°C
Storage Temperature Range ..................–65°C to 150°C
17
GND
MSE PACKAGE
16-LEAD PLASTIC MSOP
θ
JA
= 50°C/W, θ
JC
= 10°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT3799EMSE-1#PBF
LT3799IMSE-1#PBF
TAPE AND REEL
LT3799EMSE-1#TRPBF
LT3799IMSE-1#TRPBF
PART MARKING*
37991
37991
PACKAGE DESCRIPTION
16-Lead Plastic MSOPE
16-Lead Plastic MSOPE
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: /leadfree/
For more information on tape and reel specifications, go to: /tapeandreel/
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 18V, INTV
CC
= 11V, unless otherwise noted.
PARAMETER
V
IN
Turn-On Voltage
V
IN
Turn-Off Voltage
V
IN
Hysteresis
V
IN
Shunt Regulator Voltage
V
IN
Shunt Regulator Current Limit
V
IN
Quiescent Current
INTV
CC
Quiescent Current
V
IN_SENSE
Linear Range
V
REF
Voltage
Error Amplifier Voltage Gain
Error Amplifier Transconductance
0μA Load
200μA Load
ΔV
COMP
+
/ΔV
COMP
–
, CTRL1 = 1V, CTRL2 = 2V, CTRL3 = 2V
ΔI = 5μA
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONSMIN
22.2
11.8
TYP
23
12.3
10.7
25.0
MAX
24.2
13.0
UNITS
V
V
V
V
mA
V
TURNON
– V
TURNOFF
I = 1mA
15
Before Turn-On
After Turn-On
Before Turn-On
After Turn-On
55
12
1.5
0
1.97
1.95
65
70
16
2.1
2
1.98
100
50
75
20
2.6
1.3
2.03
2.03
μA
μA
μA
mA
V
V
V
V/V
μmhos
37991f
/
2