LT3791
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For more information www.linear.com/LT3791
Typical applicaTions
98% Efficient 50W (25V 2A) Buck-Boost LED Driver
R7
50Ω
C7
470nF
V
IN
4.7V TO 58V
INTV
CC
TG1
BG1
SNSP
SNSN
PGND
BST1
BST2
TEST2
BG2
SW2
TG2
RT
LT3791
SWI
R
IN
0.003Ω
SHORTLED
OPENLED
IVINN
IVINP
C3
F
V
IN
PWM
INTV
CC
IVINMON
SYNC
100Hz
300kHz
ISMON
CLKOUT
EN/UVLO
OVLO
M2
M1
M3
M4
R10
200k
V
REF
CTRL
TEST1
R8
86.6k
300kHz
V
C
SS SGND
PWMOUT
R2
121k
R9
200k
R1
332k
R3
1M
R4
54.9k
SYNC TWO
SIGNALS
R11
1M
R12
237k
C8
0.1µF
C
SS
10nF
C
C
22nF
3791 TA02a
C
IN
2.2µF
100V
×4
R
SENSE
0.004Ω
ISP
ISN
FB
R
LED
0.05Ω
25V LED
2A
C1
0.1µF
C2
0.1µF
D2D1
L1 10µH
C
VCC
4.7µF
C
OUT
4.7µF
50V
×4
R5
1M
R6
44.2k
M5
D1, D2: NXP BAT46WJ
L1: COOPER HC9-100-R 10µH
M1, M2: RENESAS RJK0651DPB 60V
DS
M3, M4: RENESAS RJK0451DPB 40V
DS
M5: VISHAY Si2318CDS 40V
DS
Efficiency vs V
IN
100Hz 1000:1 PWM Dimming
(V
IN
= 24V)
100Hz 250:1 PWM Dimming
(V
IN
= 24V)
INPUT VOLTAGE (V)
0
80
EFFICIENCY (%)
84
88
92
10
20
30 40
3791 TA02b
50
96
100
82
86
90
94
98
60
BUCK
BOOST
BUCK-BOOST
5µs/DIV
I
L1
5A/DIV
I
LED
2A/DIV
ISMON
1V/DIV
3791 TA02c
PWM
5V/DIV
5µs/DIV
I
L1
5A/DIV
I
LED
2A/DIV
ISMON
1V/DIV
3791 TA02d
PWM
5V/DIV
LT3791
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For more information www.linear.com/LT3791
FE Package
38-Lead Plastic TSSOP (4.4mm)
(Reference LTC DWG # 05-08-1772 Rev C)
Exposed Pad Variation AA
4.75
(.187)
REF
FE38 (AA) TSSOP REV C 0910
0.09 – 0.20
(.0035 – .0079)
0° – 8°
0.25
REF
0.50 – 0.75
(.020 – .030)
4.30 – 4.50*
(.169 – .177)
1
19
20
REF
9.60 – 9.80*
(.378 – .386)
38
1.20
(.047)
MAX
0.05 – 0.15
(.002 – .006)
0.50
(.0196)
BSC
0.17 – 0.27
(.0067 – .0106)
TYP
RECOMMENDED SOLDER PAD LAYOUT
0.315 ±0.05
0.50 BSC
4.50 REF
6.60 ±0.10
1.05 ±0.10
4.75 REF
2.74 REF
2.74
(.108)
MILLIMETERS
(INCHES)
*DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.150mm (.006") PER SIDE
NOTE:
1. CONTROLLING DIMENSION: MILLIMETERS
2. DIMENSIONS ARE IN
3. DRAWING NOT TO SCALE
SEE NOTE 4
4. RECOMMENDED MINIMUM PCB METAL SIZE
FOR EXPOSED PAD ATTACHMENT
6.40
(.252)
BSC
package DescripTion
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
LT3791
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For more information www.linear.com/LT3791
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
revision hisTory
REV DATE DESCRIPTION PAGE NUMBER
A 08/12 Clarified Features and Description 1
Clarified graph labels/titles 8
Clarified Pin Functions 9,10
Clarified buck-boost function 13
Clarified programming output for overvoltage or open led/overvoltage threshold 19
Clarified Typical Application 25, 28
B 12/13 Clarified TG1, TG2, t
OFF(MIN)
parameters 4

LT3791EFE#PBF

Mfr. #:
Manufacturer:
Analog Devices / Linear Technology
Description:
LED Lighting Drivers 60V 4-Switch Sync Buck-Boost LED Drvr Cn
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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