LTM8042_15 [Linear]
Module Boost LED Driver and Current Source;
| 型号： | LTM8042_15 |
| 厂家： | 
Linear |
| 描述： | Module Boost LED Driver and Current Source |
| 文件： | 总32页 (文件大小：301K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LTM8042/LTM8042-1
µModule Boost LED Driver
and Current Source
FEATURES
DESCRIPTION
n
True Color PWM™ with 3000:1 Dimming Ratio
The LTM®8042 is a complete µModule® Boost LED Driver
specifically designed to drive LEDs up to 1A, while the
LTM8042-1 drives up to 350mA. It combines a boost
power topology with a unique current loop to operate as
a constant-current source. The PWM input provides as
muchas3000:1LEDdimming,while10:1analogdimming
canbeaccomplishedbyasingleresistororanalogvoltage
applied to the CTL pin. As with any boost topology, the
LTM8042/LTM8042-1 has an uninterrupted current path
between its input and output and is thus intolerant to a
short-circuit or overload from the output to ground.
n
Operates in Boost, Buck Mode or Buck-Boost Mode
Wide Input Voltage Range:
n
Operation from 3V to 30V
Transient Protection to 40V
n
Gate Driver for Optional PWM Dimming with
P-channel MOSFET
Adjustable Frequency: 250kHz to 2MHz
n
n
Constant-Current and Constant-Voltage Regulation
n
Low Shutdown Current: <1μA
n
RoHS Compliant Package with Gold Pad Finish
n
Tiny, Low Profile (9mm × 15mm × 2.82mm)
# WHITE LEDS LED CURRENT
12V
24V
IN
IN
Surface Mount LGA Package
6
7
8
9
1A
LTM8042
350mA
1A
LTM8042-1
APPLICATIONS
LTM8042
350mA
LTM8042-1
n
Display Backlighting
n
Automotive and Avionic Lighting
The LTM8042/LTM8042-1 is packaged in a thermally
enhanced, compact overmolded land grid array (LGA)
package. The LTM8042/LTM8042-1 is Pb-free and a
RoHS compliant.
n
Illumination
Scanners
n
L, LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks
and True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are
the property of their respective owners.
TYPICAL APPLICATION
µModule Boost LED Driver, Driving 8 White LEDs at 1A
Efficiency vs VIN
97
96
95
94
93
92
91
90
89
88
UP TO 26.8V
V
IN
V
CC
LTM8042
–
16V TO 26V
+
LED
RUN
TG
BSTIN/BKLED
BSTOUT/BKIN
PWM
SYNC
TGEN
1A
SS
RT
4.7µF
GND CTL
4.7µF
33.2k
= 550kHz
87
f
16 17 18 19 20 21 22 23 24 25 26
SW
V
(V)
IN
80421 TA01b
80421 TA01a
80421fb
1
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(Note 1)
–
BSTIN/BKLED
–
V , RUN, PWM, TGEN, BSTIN/BKLED ...................40V
CC
TG
+
7
BSTOUT/BKIN, LED ................................................43V
V
BANK 2
BANK 3
BANK 4
BSTOUT/BKIN
BANK 5
CC
CTL, SYNC..................................................................6V
Internal Operating Temperature
(Notes 3, 4) ........................................... –40°C to 125°C
Maximum Reflow Body Temperature .................. 245°C
Storage Temperature ............................. –55°C to 125°C
6
5
4
3
2
1
+
LED
BANK 1
GND
TGEN
CTL
A
B
C
D
E
F
G
H
J
K
L
RUN SYNC RT SS PWM
LGA PACKAGE
77-LEAD (15mm × 9mm × 2.82mm)
= 125°C, θ = 15.7°C/W, θ = 13.6°C/W,
T
JMAX
JA
JCtop
θ
= 4.5°C/W, θ = 9.4°C/W
JCbottom
JB
θ VALUES DETERMINED PER JESD 51-12
WEIGHT = 1.1g
ORDER INFORMATION
PART MARKING*
TEMPERATURE RANGE
MSL RATING (Note 4)
PART NUMBER
PAD OR BALL FINISH
Au (RoHS)
DEVICE
FINISH CODE
PACKAGE TYPE
LTM8042EV#PBF
LTM8042IV#PBF
LTM8042EV-1#PBF
LTM8042IV-1#PBF
LTM8042V
LTM8042V
LTM8042V-1
LTM8042V-1
e4
e4
e4
e4
LGA
LGA
LGA
LGA
3
3
3
3
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
Au (RoHS)
Au (RoHS)
Au (RoHS)
Consult Marketing for parts specified with wider operating temperature
ranges. *Device temperature grade is indicated by a label on the shipping
container. Pad or ball finish code is per IPC/JEDEC J-STD-609.
• Recommended LGA and BGA PCB Assembly and Manufacturing
Procedures:
www.linear.com/umodule/pcbassembly
• LGA and BGA Package and Tray Drawings:
www.linear.com/packaging
• Terminal Finish Part Marking:
www.linear.com/leadfree
80421fb
2
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, buck mode with 4Ω load.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
l
V
Minimum Input DC Voltage
LTM8042 LED Current
3
V
CC(MIN)
LED
I
CTL Open
CTL
0.9
1.05
0.55
0.39
0.20
A
A
A
A
R
= 6.81k
0.45
0.34
0.17
0.5
36
LTM8042-1 LED Current
CTL Open
= 6.81k
R
CTL
+
V
Open LED Clamp Voltage
Boost Mode, LED Open
V
CLAMP
∆I /I
OUT OUT
Output Current Line Regulation
LTM8042, 6V < BSTOUT/BKIN < 30V
LTM8042-1, 6V < BSTOUT/BKIN < 30V
0.5
0.5
%
%
I
f
V
Supply Current
CC
PWM = 0V
RUN = 0V
4.2
0.1
mA
µA
QVCC
SW
1
Switching Frequency
RT = 90.9k
RT = 22.1k
RT = 6.04k
0.22
0.68
1.7
0.25
0.8
2
0.27
0.92
2.3
MHz
MHz
MHz
I
f
I
Soft-Start Pin Current
SS = 0.5V, Out of Pin
6
9
12
µA
MHz
µA
V
SS
Synchronization Frequency Range
SYNC Pull-Down Current (Into the Pin)
SYNC Input Low
0.3
2.5
SYNC
SYNC
V
= 2V
60
SYNC
V
V
0.4
SYNC(IL)
SYNC(IH)
CTL
SYNC Input High
1.5
1.5
V
I
CTL Input Bias Current
RUN Input Voltage High
RUN Input Voltage Low
RUN Pin Bias Current
CTL = 0V, Flows Out of Pin
100
60
µA
V
V
V
RUN(IH)
RUN(IL)
RUN
0.4
V
I
100
µA
V
V
V
PWM Input Voltage High
PWM Input Voltage Low
PWM Pin Bias Current
TG Output High Voltage
TG Output Low Voltage
TGEN Input Voltage High
TGEN Input Voltage Low
TGEN Pin Bias Current
1.5
1.5
PWM(IH)
PWM(IL)
PWM
0.4
V
I
60
0
120
µA
V
+
+
V
V
V
V
Relative to LED , 100k from LED to TG
TG(OH)
TG(OL)
+
+
Relative to LED , 100k from LED to TG
PWM = 0V
–7
V
V
TGEN(IH)
TGEN(IL)
TGEN
0.4
V
I
100
200
µA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
The LTM8042I/LTM8042I-1 are guaranteed to meet specifications over
the full –40°C to 125°C internal operating temperature range. Note that
the maximum internal temperature is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
resistance and other environmental factors.
Note 4: This device includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed the maximum internal operating temperature
when overtemperature protection is active. Continuous operation above
the specified maximum operating junction temperature may impair device
reliability.
Note 2: Absolute maximum voltage at V , RUN, PWM, TGEN, BSTIN/
CC
–
BKLED pins is 40V for non-repetitive one second transients and 30V for
continuous operation.
Note 3: The LTM8042E/LTM8042E-1 are guaranteed to meet performance
specifications from 0°C to 125°C ambient. Specifications over the full
–40°C to 125°C internal operating temperature range are assured by
design, characterization and correlation with statistical process controls.
80421fb
3
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042
Efficiency vs VIN, Boost Operation,
6.8V at 1A LED String
Efficiency vs VIN, Boost Operation,
10.1V at 1A LED String
Efficiency vs VIN, Boost Operation,
13.4V at 1A LED String
90
89
88
87
86
85
84
83
82
81
80
95
94
93
92
91
90
89
88
87
86
85
94
92
90
88
86
84
82
80
5
6
7
8
9
10
4
5
6
7
8
9
10
(V)
11
12
13
V
(V)
V
(V)
V
IN
IN
IN
80421 G02
80421 G01
80421 G03
Efficiency vs VIN, Boost Operation,
16.7V at 1A LED String
Efficiency vs VIN, Boost Operation,
20.1V at 1A LED String
Efficiency vs VIN, Boost Operation,
23.4V at 1A LED String
97
95
93
91
89
87
85
83
97
95
93
91
89
87
85
83
94
92
90
88
86
84
82
80
11 12 13 14 15 16 17 18 19
(V)
12 13 14 15 16 17 18 19 20 21 22
8
9
10 11 12 13 14 15 16
(V)
V
V
(V)
V
IN
IN
IN
80421 G05
80421 G06
80421 G04
Efficiency vs VIN, Buck Mode,
3.5V at 1A LED String
Efficiency vs VIN, Buck Mode,
6.8V at 1A LED String
Efficiency vs VIN, Boost Operation,
26.8V at 1A LED String
97
96
95
94
93
92
91
90
89
88
87
89
87
85
83
81
79
77
75
94
92
90
88
86
84
82
80
16 17 18 19 20 21 22 23 24 25 26
4
6
8 10 12 14 16 18 20 22 24 26 28 30 32 34
(V)
8
10 12 14 16 18 20 22 24 26 28 30 32 34
(V)
V
(V)
V
V
IN
IN
IN
80421 G07
80421 G08
80421 G09
80421fb
4
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042
Efficiency vs VIN, Buck Mode,
Efficiency vs VIN, Buck Mode,
13.4V at 1A LED String
Efficiency vs VIN, Buck Mode,
10.1V at 1A LED String
16.7V at 1A LED String
95
94
93
92
91
90
89
88
87
86
85
97
96
95
94
93
92
91
90
89
88
87
97
96
95
94
93
92
91
90
89
88
87
12 14 16 18 20 22 24 26 28 30 32 34
15 17 19 21 23 25 27 29 31 33
(V)
19
21
23
25
27
29
31
33
V
(V)
V
V
(V)
IN
IN
IN
80421 G10
80421 G11
80421 G12
Efficiency vs VIN, Buck-Boost
Mode, 3.6V at 1A LED String
Efficiency vs VIN, Buck-Boost
Mode, 6.8V at 1A LED String
Efficiency vs VIN, Buck-Boost
Mode, 10.1V at 1A LED String
90
85
80
75
70
85
80
75
70
65
60
55
87
86
85
84
83
82
81
80
8
10 12 14 16 18 20 22 24 26
(V)
4
6
8
10 12 14 16 18 20 22 24 26 28 30
(V)
12 13 14 15 16 17 18 19 20 21 22 23 24
V
V
V
(V)
IN
IN
IN
80421 G14
80421 G13
80421 G15
Maximum LED Current
vs Input Voltage, Boost Operation
Efficiency vs VIN, Buck-Boost
Mode, 13.4V at 1A LED String
90
89
88
87
86
85
84
83
82
81
80
1200
1000
800
600
400
200
0
7.4V AT 1A
10.9V AT 1A
14.5V AT 1A
18.1V AT 1A
21.4V AT 1A
24.8V AT 1A
28.2V AT 1A
15
16
17
18
19
20
0
5
10
15
20
25
30
V
(V)
INPUT VOLTAGE (V)
IN
80421 G16
80421 G17
80421fb
5
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042
Maximum LED Current
vs VIN, Buck Mode
Maximum LED Current vs Input
Voltage, Buck-Boost Mode
1000
900
800
700
600
500
400
300
200
100
0
1200
1000
800
600
400
200
0
3.8V AT 1A
7.4V AT 1A
10.9V AT 1A
14.5V AT 1A
18.1V AT 1A
21.4V AT 1A
24.8V AT 1A
7.4V AT 1A
10.9V AT 1A
14.5V AT 1A
18.1V AT 1A
21.4V AT 1A
24.8V AT 1A
28.2V AT 1A
0
5
10
15
(N)
20
25
30
0
10
20
30
40
V
INPUT VOLTAGE (V)
IN
80421 G18
80421 G19
Junction Temperature Rise
vs Load, Boost Operation,
8.3V at 1A LED String
Quiescent Current
vs Input Voltage, Open LED
LED Current vs CTL Voltage
40
25
20
15
10
5
100
80
60
40
20
0
35
30
25
20
15
10
5
5V
IN
0
0
0
200
400
600
800 1000 1200
0
5
10
15
20
25
30
0
200
400
600
800
1000
ADJUST VOLTAGE (mV)
INPUT VOLTAGE (V)
LED CURRENT (mA)
80421 G20
80421 G21
80421 G22
Junction Temperature Rise
vs Load, Boost Operation,
10.9V at 1A LED String
Junction Temperature Rise
vs Load, Boost Operation,
13.6V at 1A LED String
Junction Temperature Rise
vs Load, Boost Operation,
18.1V at 1A LED String
20
18
16
14
12
10
8
35
30
25
20
15
10
5
25
20
15
10
5
8V
IN
9V
IN
7V
IN
6
4
2
0
0
0
0
200
400
600
800
1000
0
200
400
600
800
1000
0
200
400
600
800
1000
LED CURRENT (mA)
LED CURRENT (mA)
LED CURRENT (mA)
80421 G23
80421 G25
80421 G24
80421fb
6
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042
Junction Temperature Rise vs Load,
Buck Mode, 2.9V at 1A LED String
Junction Temperature Rise vs Load,
Buck Mode, 3.8V at 1A LED String
Junction Temperature Rise vs Load,
Buck Mode, 8.3V at 1A LED String
18
16
14
12
10
8
25
20
15
10
5
18
16
14
12
10
8
24V
IN
24V
IN
24V
IN
12V
IN
12V
IN
12V
IN
6
6
4
4
2
2
0
0
0
0
200
400
600
800
1000
0
200
400
600
800
1000
0
200
400
600
800
1000
LED CURRENT (mA)
LED CURRENT (mA)
LED CURRENT (mA)
80421 G26
80421 G28
80421 G27
Junction Temperature Rise vs Load,
Buck Mode, 18.1V at 1A LED String
Junction Temperature Rise vs Load,
Buck Mode, 10.9V at 1A LED String
Junction Temperature Rise vs Load,
Buck Mode, 13.6V at 1A LED String
25
20
15
10
5
25
20
15
10
5
30
25
20
15
10
5
24V
IN
24V
IN
24V
IN
0
0
0
0
200
400
600
800
1000
0
200
400
600
800
1000
0
200
400
600
800
1000
LED CURRENT (mA)
LED CURRENT (mA)
LED CURRENT (mA)
80421 G29
80421 G31
80421 G30
Junction Temperature Rise
vs Load, Buck-Boost Mode,
3.8V at 1A LED String
Junction Temperature Rise
vs Load, Buck-Boost Mode,
8.3V at 1A LED String
Junction Temperature Rise
vs Load, Buck-Boost Mode,
2.9V at 1A LED String
40
35
30
25
20
15
10
5
30
25
20
15
10
5
25
20
15
10
5
5V
IN
24V
IN
12V
IN
24V
IN
5V
12V
IN
IN
12V
IN
0
0
0
0
200
400
600
800
1000
0
200
400
600
800
1000
0
200
400
600
800
1000
LED CURRENT (mA)
LED CURRENT (mA)
LED CURRENT (mA)
80421 G34
80421 G33
80421 G32
80421fb
7
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042
Junction Temperature Rise
vs Load, Buck-Boost Mode,
10.9V at 1A LED String
Junction Temperature Rise
vs Load, Buck-Boost Mode,
13.6V at 1A LED String
Junction Temperature Rise
vs Load, Buck-Boost Mode,
15.5V at 350mA LED String
50
45
40
35
30
25
20
15
10
5
60
50
40
30
20
10
0
25
20
15
10
5
12V
IN
12V
IN
16V
IN
12V
IN
0
0
0
200
400
600
800
1000
0
200
400
600
800
1000
0
50 100 150 200 250 300 350
LED CURRENT (mA)
LED CURRENT (mA)
LED CURRENT (mA)
80421 G35
80421 G36
80421 G37
LTM8042/LTM8042-1
RUN Pin Current vs Voltage
160
140
120
100
80
60
40
20
0
0
10
20
30
40
RUN VOLTAGE (V)
80421 G38
LTM8042-1
Efficiency vs VIN, Boost Operation,
6.7V at 350mA LED String
Efficiency vs VIN, Boost Operation,
9.7V at 350mA LED String
Efficiency vs VIN, Boost Operation,
12.6V at 350mA LED String
95
95
90
85
80
75
70
65
95
90
85
80
75
70
65
90
85
80
75
70
65
2.5
4.5
6.5
8.5
2
3
4
5
6
3
5
7
9
11
V
(V)
V
(V)
V
(V)
IN
IN
IN
80421 G40
80421 G39
80421 G41
80421fb
8
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042-1
Efficiency vs VIN, Boost Operation,
15.6V at 350mA LED String
Efficiency vs VIN, Boost Operation,
18.6V at 350mA LED String
Efficiency vs VIN, Boost Operation,
21.6V at 350mA LED String
95
90
85
80
75
70
65
95
90
85
80
75
70
65
95
90
85
80
75
70
65
4
5
6
7
8
9
10 11 12 13 14 15
(V)
5
6
7
8
9
10 11 12 13 14 15 16 17 18
(V)
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18
(V)
V
V
V
IN
IN
IN
80421 G42
80421 G44
80421 G43
Efficiency vs VIN, Boost Operation,
24.8V at 350mA LED String
Efficiency vs VIN, Buck Mode,
3.7V at 350mA LED String
Efficiency vs VIN, Buck Mode,
6.7V at 350mA LED String
93
91
89
87
85
83
81
79
77
75
96
94
92
90
88
86
84
82
80
93
91
89
87
85
83
81
79
77
75
4
6
8 10 12 14 16 18 20 22 24 26 28 30 32
(V)
8
10 12 14 16 18 20 22 24 26 28 30 32 34
(V)
6
8
10 12 14 16 18 20 22 24
(V)
V
V
V
IN
IN
IN
80421 G46
80421 G47
80421 G45
Efficiency vs VIN, Buck Mode,
9.7V at 350mA LED String
Efficiency vs VIN, Buck Mode,
12.6V at 350mA LED String
Efficiency vs VIN, Buck Mode,
15.6V at 350mA LED String
97
95
93
91
89
87
85
98
96
94
92
90
88
86
84
82
80
97
95
93
91
89
87
85
14 16 18 20 22 24 26 28 30 32
(V)
11 13 15 17 19 21 23 25 27 29 31 33
(V)
17 19 21 23 25 27 29 31 33
(V)
V
V
V
IN
IN
IN
80421 G49
80421 G48
80421 G50
80421fb
9
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042-1
Efficiency vs VIN, Buck Mode,
18.6V at 350mA LED String
Efficiency vs VIN, Buck-Boost
Mode, 3.7V at 350mA LED String
Efficiency vs VIN, Buck-Boost
Mode, 6.7V at 350mA LED String
97
95
93
91
89
87
85
90
85
80
75
70
65
60
55
50
45
40
90
80
70
60
50
40
30
20
10
0
21
23
25
27
29
31
33
0
5
10
15
(V)
20
25
30
0
10
20
(V)
30
40
V
(V)
V
V
IN
IN
IN
80421 G51
80421 G53
80421 G52
Efficiency vs VIN, Buck-Boost
Mode, 9.7V at 350mA LED String
Efficiency vs VIN, Buck-Boost
Mode, 12.6V at 350mA LED String
Efficiency vs VIN, Buck-Boost
Mode, 15.6V at 350mA LED String
88
86
84
82
80
78
76
74
72
70
90
85
80
75
70
65
60
55
50
90
85
80
75
70
65
60
0
10
15
20
0
5
10
15
(V)
20
25
30
0
5
10
15
20
25
V
(V)
V
V
(V)
IN
IN
IN
80421 G56
80421 G54
80421 G55
Efficiency vs VIN, Buck-Boost
Mode, 18.6V at 350mA LED String
Maximum LED Current vs Input
Voltage, Boost Operation
Maximum LED Current vs Input
Voltage, Buck Mode
87
85
83
81
79
77
75
400
350
300
250
200
150
100
50
400
350
300
250
200
150
100
50
3.2V AT 350mA
6.3V AT 350mA
9.4V AT 350mA
12.4V AT 350mA
15.5V AT 350mA
18.6V AT 350mA
6.3V AT 350mA
15.5V AT 350mA
18.6V AT 350mA
21.7V AT 350mA
24.8V AT 350mA
0
0
5
7
9
11
13
15
0
5
10
15
20
25
0
10
20
30
40
V
(V)
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
IN
80421 G57
80421 G58
80421 G59
80421fb
10
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042-1
Quiescent Current vs Input
Maximum LED Current vs Input
LED Current vs CTL Voltage
Voltage, Open LED
Voltage, Buck-Boost Mode
400
350
300
250
200
150
100
50
120
100
80
60
40
20
0
80
70
60
50
40
30
20
10
0
3.2V AT 350mA
6.3V AT 350mA
9.4V AT 350mA
12.4V AT 350mA
15.5V AT 350mA
18.6V AT 350mA
0
0
10
20
30
40
0
200
400
600
800 1000 1200
0
5
10
15
20
25
30
35
INPUT VOLTAGE (V)
CTL VOLTAGE (mV)
INPUT VOLTAGE (V)
80421 G60
80421 G61
80421 G62
Junction Temperature Rise
vs Load, Boost Operation,
6.8V at 350mA LED String
Junction Temperature Rise
vs Load, Boost Operation,
9.4V at 350mA LED String
Junction Temperature Rise
vs Load, Boost Operation,
11.2V at 350mA LED String
5
4
3
2
1
0
8
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
5V
IN
5V
IN
5V
IN
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
80421 G63
80421 G65
80421 G64
Junction Temperature Rise
vs Load, Boost Operation,
15.5V at 350mA LED String
Junction Temperature Rise
vs Load, Buck Mode,
Junction Temperature Rise
vs Load, Buck Mode,
2.3V at 350mA LED String
3.2V at 350mA LED String
10
9
8
7
6
5
4
3
2
1
0
6
5
4
3
2
1
0
14
12
10
8
24V
IN
5V
IN
12V
IN
6
12V
IN
4
5V
IN
2
0
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
80421 G67
80421 G68
80421 G66
80421fb
11
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042-1
Junction Temperature Rise
vs Load, Buck Mode,
6.8V at 350mA LED String
Junction Temperature Rise
vs Load, Buck Mode,
Junction Temperature Rise
vs Load, Buck Mode,
9.4V at 350mA LED String
11.2V at 350mA LED String
14
12
10
8
14
12
10
8
12
10
8
24V
IN
24V
IN
24V
IN
6
6
6
12V
IN
4
4
4
2
2
2
0
0
0
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
80421 G71
80421 G70
80421 G69
Junction Temperature Rise
vs Load, Buck-Boost Mode,
2.3V at 350mA LED String
Junction Temperature Rise
vs Load, Buck-Boost Mode,
3.2V at 350mA LED String
Junction Temperature Rise
vs Load, Buck Mode,
15.5V at 350mA LED String
10
8
12
10
8
14
12
10
8
24V
IN
24V
IN
24V
IN
12V
IN
6
12V
IN
6
6
4
4
4
2
5V
IN
5V
IN
IN
2
2
3.3V
3.3V
IN
0
0
0
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
80421 G73
80421 G74
80421 G72
Junction Temperature Rise
vs Load, Buck-Boost Mode,
9.4V at 350mA LED String
Junction Temperature Rise
vs Load, Buck-Boost Mode,
6.8V at 350mA LED String
16
14
12
10
8
12
10
8
12V
IN
12V
IN
6
5V
IN
5V
IN
6
4
4
2
2
0
0
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
80421 G76
80421 G75
80421fb
12
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042-1
Junction Temperature Rise
vs Load, Buck-Boost Mode,
11.2V at 350mA LED String
Junction Temperature Rise
vs Load, Buck-Boost Mode,
15.5V at 350mA LED String
30
25
20
15
10
5
18
16
14
12
10
8
12V
IN
12V
IN
5V
IN
6
5V
IN
4
2
0
0
0
50 100 150 200 250 300 350
LED CURRENT (mA)
0
50 100 150 200 250 300 350
LED CURRENT (mA)
80421 G78
80421 G77
PIN FUNCTIONS
+
GND (Bank 1): Signal and Power Return. Tie these pads
to a local ground plane below the LTM8042/LTM8042-1
and the circuit components. In most applications, the
bulk of the heat flow out of the LTM8042/LTM8042-1 is
through these pads, so the printed circuit design has a
large impact on the thermal performance of the part. See
the PCB Layout and Thermal Considerations sections for
more details.
LED (Bank 5): Connect this to the anode of the LED
string. This can also be connected to the PWM dimming
MOSFET if used.
RUN (Pin F1): Module Enable. Tie to 1.5V or higher to
enable the LTM8042/LTM8042-1 or 0.4V or less to dis-
able device.
SYNC (Pin G1): Frequency Synchronization Pin. Tie an
external clock signal here. The RT resistor should be
chosen to program a switching frequency that is 20%
slower than SYNC pulse frequency. Tie the SYNC pin to
GND if this feature is not used.
V
(Bank 2): Internal Housekeeping Power for the
CC
LTM8042/LTM8042-1. Connect to an external power
source between 3V and 30V. The LTM8042/LTM8042-1
can withstand transients of 40V.
RT (Pin H1): Timing Resistor Pin. Used to program the
switching frequency of the LTM8042/LTM8042-1 by con-
necting a resistor from this pin to GND. The Applications
Information section of the data sheet includes a table
to determine the resistance value based on the desired
switching frequency. Minimize capacitance at this pin.
–
BSTIN/BKLED (Bank3):PowerInputforBoostOperation,
as Well as the Cathode Connection for the LED String in
Buck Mode. If the LTM8042/LTM8042-1 is used in boost
mode, these pins must be locally decoupled.
BSTOUT/BKIN (Bank 4): Output of the Boost Converter,
as Well as the Input for Buck Mode. If the LTM8042/
LTM8042-1 is used in buck mode, these pins must be
locally decoupled.
SS (Pin J1): Soft-Start Pin. Place a soft-start capacitor
here. Leave the pin open if not used.
80421fb
13
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
PIN FUNCTIONS
TG (Pin J7): Top Gate Driver Output. In response to an
active high PWM signal, this pin will drive the gate of an
external series P-channel MOSFET device low. An inter-
nal 7V clamp protects the PFET gate. This pin can also
be used to disconnect the load when RUN is pulled low.
Leave TG unconnected if not used. Do not drive this pin
with an external source.
CTL (Pin L2): LED Current Adjustment Pin. Apply a volt-
age between approximately 1V and 0V to modulate the
+
LED output current, or tie a resistor to GND to modulate
+
the LED current. CTL is internally tied to a 2V precision
reference via a 20k 1% resistor. Leave floating if unused.
TGEN (Pin L3): Top Gate (TG) Enable Input Pin. Tie to 1.5V
orhighertoenabletheP-channelMOSFETdriverfunction.
Tie the TGEN pin to ground if the TG function is not used.
There is an internal 40k resistor from TGEN to GND.
PWM (Pin K1): Pulse Width Modulation Input Pin. A low
signal turns off the LED string, disables the main switch
and pulls the TG pin high. Drive above 1.55V to deliver
current to the output. Tie the PWM pin to the RUN pin if
not used. There is an equivalent 50k resistor from PWM
pin to ground internally.
BLOCK DIAGRAM
BSTOUT/BKIN
–
4.7µH
BSTIN/BKLED
0.1µF
0.1µF
0.1µF
1M
R
SNS
0.10Ω (LTM8042)
0.27Ω (LTM8042-1)
V
+
CC
LED
OPEN LED
PROTECTION
(1V THRESHOLD)
28.0k
CURRENT
MODE LED
CONTROLLER
RUN
SS
CURRENT SENSE+
CURRENT SENSE–
TG
PWM
2V
20.0k
1%
50k
SYNC
GND
RT
TGEN
CTL
80421 BD
80421fb
14
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
OPERATION
The LTM8042/LTM8042-1 is a complete, full featured,
current mode regulator specifically designed to drive light
emitting diodes (LEDs) or other loads where a constant
current up to 1A (350mA for the LTM8042-1) is required.
The other way the LTM8042/LTM8042-1 can dim a LED
array is by pulse width modulation using the PWM pin
and an optional external P-channel MOSFET. The external
P-channel MOSFET can be conveniently operated by the
integrated gate driver at pin TG. The gate drive function
can be enabled or disabled by the TGEN pin.
TheLTM8042/LTM8042-1canoperateinanyofthreeLED
drivetopologies:boost,buckmodeandbuck-boostmode.
ThedevicefeaturesbothanalogandPWM dimming,aPWM
P-channelMOSFETdriver,andasuiteofcontrolfunctions:
RUN control, soft-start, user programmable switching
frequency, and external frequency synchronization.
IfthePWM pinispulledhigh, thepartoperatesnormally. If
the PWM pin is unconnected or pulled low, the LTM8042/
LTM8042-1 stops switching and the internal control cir-
cuitry is held in its present state. This way, the LTM8042/
LTM8042-1 “remembers” the current sourced from the
Operation can be best understood by referring to the
Block Diagram. The power stage is a boost converter that
regulates the output current by reading the voltage across
a power sense resistor that is in series with the output.
+
LED output until PWM is pulled high again. This leads to
ahighlylinearrelationshipbetweenpulsewidthandoutput
light, allowing for a large and accurate dimming range.
TheRUNpinisusedtodeactivatetheLTM8042/LTM8042-1.
When the RUN pin is pulled to a logic low state, the device
is shut down and draws typically less than 1µA of current.
As with any boost topology, there is an uninterrupted cur-
rent path between the input and output terminals. Current
between these two terminals is not limited, so the device
isintoleranttoashort-circuitoroverloadfromanyofthe
The SS pin is used to limit inrush current during start-up.
TheLTM8042/LTM8042-1integratesacurrentsourcewith
this function, so only a capacitor is necessary to establish
the soft-start characteristics of the output current.
+
output terminals (LED , BSTOUT/BKIN) to GND.
There are two ways to dim a LED with the LTM8042/
LTM8042-1. One way is to adjust the current on the LED
array by setting the analog voltage on the CTL pin. The
CTL pin is internally pulled up to a precision 2V reference
through a 1% 20k resistor. Leaving the CTL pin floating
setstheLEDpincurrentto1A. Reducingthevoltagebelow
1.1V on the CTL pin proportionally reduces the current
Theswitchingfrequencyissetbyapplyingasingleresistor
fromtheRT pintoGND,allowingoperationanywherefrom
250kHz to 2MHz, and the SYNC pin allows synchroniza-
tion to an external source between 300kHz and 2.5MHz.
+
flowing out of LED . This can be accomplished by con-
necting a resistor from the CTL pin to GND, forming a
dividernetworkwiththeinternal20kresistor, orbydriving
the CTL pin directly to a voltage source, such as a DAC.
80421fb
15
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
For most applications, the design process is straight
forward, summarized as follows:
Setting the Switching Frequency
The LTM8042/LTM8042-1 uses a constant frequency
architecture that can be programmed over a 250kHz to
2MHz range with a single external timing resistor from the
RT pin to ground. Table 7 shows suggested R selections
for a variety of switching frequencies.
1. DecidewhethertheLTM8042/LTM8042-1shouldoper-
ate in boost, buck, or buck-boost mode.
T
2. Look at Tables 1 through 6 and find the line that best
matches the input and output conditions of the system
under consideration.
Table 7. Switching Frequency vs RT
SWITCHING FREQUENCY (kHz)
R (kΩ)
T
3. Connect C , C , C
and R as indicated in the
T
IN OUT VCC
appropriate table.
250
500
86.6
37.4
21.0
15.8
9.09
6.04
4. Connect the remaining pins as needed by the system
requirements.
800
1000
1500
2000
While these component combinations have been tested
for proper operation, it is incumbent upon the user to
verify proper operation over the intended system’s line,
load and environmental conditions.
The other way to set the operating frequency of the
LTM8042/LTM8042-1 is to drive the SYNC pin with an
external signal. For proper operation, a resistor should be
connected at the RT pin and be able to generate a switch-
ing frequency 20% lower than the external clock when the
external clock is absent.
IfthedesiredLEDcurrentisnotlistedinTables1through6,
set it by applying the proper voltage the CTL pin. Graphs
of the LTM8042/LTM8042-1 LED current scaling vs CTL
voltage are given in the Typical Performance Character-
istics section. If a voltage source is not available to drive
the CTL pin, a resistor may be applied from the CTL pin
to GND. The CTL pin is internally pulled up to a 2V refer-
ence voltage through a 20k resistor (please see the Block
Diagram for details).
In general, a lower switching frequency should be used
where either very high or very low switching duty cycle
operationisrequired,orhighefficiencyisdesired.Selection
of a higher switching frequency will allow use of smaller
value external components and yield a smaller solution
size and profile.
Open LED Protection
The LTM8042/LTM8042-1 has internal open LED circuit
protection.IftheLEDisabsentorfailsopen,theLTM8042/
LTM8042-1 clamps the voltage on the LED+ and BSTOUT/
BKIN pin to protect the output against overvoltage. The
internal boost switching converter then regulates its
output to 36V. In buck mode, the full open LED voltage
is stood off by the internal power Schottky diode. At high
operating temperatures, the power Schottky reverse leak-
age current will rise. This increases the power dissipation
within the diode, which raises the junction temperature.
This temperature rise can be large, so care needs to be
taken at high operating temperatures.
Operating Modes
The LTM8042/LTM8042-1 employs a ground referred
power switch to implement a boost power switching
circuit. As such, it can be used to implement the three
most popular LED driving topologies: boost, buck mode,
and buck-boost mode. Example layouts of each operating
mode are given in Figures 2 through 4 and schematics are
shown in the Typical Applications section.
80421fb
16
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
Which mode to use depends upon the operating condi-
tions. Boost is generally selected when the voltage across
theLEDstringisalwayshigherthantheinputvoltage.Buck
mode is the dual of boost, used when the voltage across
The minimum PWM on or off-time will depend on the
choice of operating frequency through the RT input pin or
the SYNC pin. When using the SYNC function, the SYNC
and PWM signals must have the rising edges aligned to
achieve the optimized high PWM dimming ratio. For best
current accuracy, the minimum PWM low or high time
theLEDstringisalwayslowerthanV .Finally,buck-boost
IN
mode is used when the V can vary both above and below
IN
the voltage across the LED string.
should be at least six switching cycles (3μs for ƒ
=
SW
2MHz). The maximum PWM period is determined by the
ThelandgridarrayoftheLTM8042/LTM8042-1isdesigned
to conveniently accommodate all three operating modes.
Please refer to the PCB Layout section for suggested
examples of how to lay out each operating mode.
system. The maximum PWM dimming ratio (PWM
)
)
RATIO
can be calculated from the maximum PWM period (T
MAX
and the minimum PWM pulse width (T ) as follows:
MIN
TMAX
TMIN
PWMRATIO
=
(1)
Dimming Control
There are two methods to control the current source for
dimming using the LTM8042/LTM8042-1. One method
usesthePWM pintomodulatethecurrentsourcebetween
zero and full current to achieve a precisely programmed
average current. To make this method of current control
more accurate, the switch demand current is internally
storedduringthequiescentphase(PWM low).Thisfeature
minimizes recovery time when the PWM signal returns
high.WhenusingPWM dimming,useaP-channelMOSFET
disconnect switch in the LED current path (see Figure 1)
to prevent the output capacitor from discharging during
the PWM off-time. Enable this function by pulling TGEN
above 1.5V.
A set of values that give a 3000:1 dimming ratio, for ex-
ample, would be a switching frequency of ƒ = 2MHz,
SW
T
= 9ms and T
= 3μs. Equation (1) becomes:
MAX
MIN
PWM
= 9ms/3μs = 3000:1
RATIO
The second method of dimming control uses the CTL pin
to linearly adjust the current sense threshold during the
PWM high state. When the CTL pin voltage is less than
1V, the LED current is:
ILED = VCTL
WhenV ishigherthan1.1V, theLEDcurrentisclamped
CTL
to 1A.
The LED current programming feature can be used in
conjunction with the PWM to possibly increase the total
dimming range by an additional factor of ten.
LTM8042
+
V
V
LED
IN
CC
–
BSTIN/BKLED
RUN
TG
TGEN
PWM
SYNC
SS
BSTOUT/BKIN
RT GND CTL
80421 TA01a
Figure 1. The LTM8042/LTM8042-1
Can Control a P-Channel PWM Switch
80421fb
17
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
PCB Layout
Most of the headaches associated with PCB layout have
been alleviated or even eliminated by the high level of
integration of the LTM8042/LTM8042-1. The device is
nevertheless a switching power supply, and care must be
taken to minimize EMI and ensure proper operation. Even
with the high level of integration, you may fail to achieve
specified operation with a haphazard or poor layout. See
Figures 2, 3 and 4 for suggested layouts of boost, buck
and buck-boost operating modes.
4. Place the C , C
and C
capacitors such that their
OUT
IN VCC
ground current flows directly adjacent to or underneath
the LTM8042/LTM8042-1.
5. Connect all of the GND connections to as large a copper
pour or plane area as possible on the top layer. Avoid
breaking the ground connection between the external
components and the LTM8042/LTM8042-1.
Use vias to connect the GND copper area to the board’s
internalgroundplanes. LiberallydistributetheseGNDvias
to provide both a good ground connection and thermal
path to the internal planes of the printed circuit board.
Pay attention to the location and density of the thermal
vias in Figures 2 through 4. The LTM8042/LTM8042-1
can benefit from the heat sinking afforded by vias that
connect to internal GND planes at these locations, due to
their proximity to internal power handling components.
The optimum number of thermal vias depends upon the
printed circuit board design. For example, a board might
use very small via holes. It should employ more thermal
vias than a board that uses larger holes.
Ensurethatthegroundingandheatsinkingareacceptable.
A few rules to keep in mind are:
1. Place the R resistor as close as possible to its re-
T
spective pins.
2. Place the C and C
capacitor as close as possible
IN
VCC
to the V and GND connections of the LTM8042/
IN
LTM8042-1.
3. Place the C
capacitor as close as possible to the
OUT
–
BSTOUT/BKIN or BSTIN/BKLED and GND connection
of the LTM8042/LTM8042-1.
TO LED STRING
GND
C
C
OUT
+
IN
LED
LED
V
IN
–
BSTIN/BKLED
TG
+
V
CC
BSTOUT/BKIN
C
VCC
GND
TGEN
CTL
80421 F02
GND
R
T
THERMAL VIAS TO GROUND PLANE
Figure 2. Suggested Layout for Boost Operation
80421fb
18
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
TO LED STRING
C
OUT
V
V
IN
IN
+
LED
C
VCC
C
IN
–
BSTIN/BKLED
TG
+
V
LED
CC
BSTOUT/BKIN
GND
TGEN
CTL
80421 F03
GND
R
T
THERMAL VIAS TO GROUND PLANE
Figure 3. Suggested Layout for Buck Mode
TO LED STRING
TO LED STRING
C
OUT2
C
OUT1
+
LED
C
–
IN
V
IN
BSTIN/BKLED
TG
+
V
LED
CC
BSTOUT/BKIN
C
VCC
TGEN
CTL
80421 F04
GND
R
T
THERMAL VIAS TO GROUND PLANE
Figure 4. Suggested Layout for Buck-Boost Mode
80421fb
19
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
Table 1. LTM8042 Recommended Values and Configuration for Boost (TA = 25°C)
LED
V
STRING
IN
RANGE
(BSTIN/
C
C
VOLTAGE
LED
RT
f
IN
OUT
–
+
(BSTIN/BKLED
TO GND)
(BSTOUT/BKIN
TO GND)
(LED TO STRING
(OPTI- (OPTI- RT
f
–
BKLED )
V
GND)
CURRENT
35mA
35mA
35mA
35mA
35mA
35mA
35mA
100mA
100mA
100mA
100mA
100mA
100mA
100mA
350mA
350mA
350mA
350mA
350mA
350mA
350mA
500mA
500mA
500mA
500mA
500mA
500mA
500mA
700mA
700mA
700mA
700mA
700mA
700mA
700mA
1A
R
MAL) MAL) (MIN) (MAX)
86.6k 250k 37.4k 500k
76.8k 275k 37.4k 500k
69.8k 300k 37.4k 500k
48.7k 400k 30.1k 600k
37.4k 500k 27.4k 650k
33.2k 550k 24.9k 700k
30.1k 600k 24.9k 700k
CC
CTL
3V to 3.6V
3V to 5.1V
3V to 6.3V
3V to 9.3V
3V to 10V
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED– 4.7µF 1206 X7R 10V 2.2µF 1206 X7R 10V
Connect to BSTIN/BKLED– 4.7µF 1206 X7R 10V 2.2µF 1206 X7R 10V
Connect to BSTIN/BKLED– 4.7µF 1206 X7R 10V 2.2µF 1206 X7R 16V 8V to 12V
Connect to BSTIN/BKLED– 4.7µF 1206 X7R 16V 2.2µF 1206 X7R 16V 12V to 16V
Connect to BSTIN/BKLED– 4.7µF 1206 X7R 16V 2.2µF 1206 X7R 25V 15V to 21V
Connect to BSTIN/BKLED– 2.2µF 1206 X7R 16V 2.2µF 1206 X7R 25V 18V to 24V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 16V
1µF 0805 X7R 16V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 16V
1µF 0805 X7R 16V
1µF 0805 X7R 25V
1µF 0805 X7R 25V
1µF 0805 X7R 50V
4V to 6V
523
523
523
523
523
523
523
6V to 9V
8V to 12V
12V to 16V
15V to 21V
18V to 24V
24V to 32V
4V to 6V
3V to 12.6V
3.7V to 15V
3V to 3.85V
3V to 5.6V
3V to 7V
1.30k 86.6k 250k 37.4k 500k
1.30k 76.8k 275k 37.4k 500k
1.30k 69.8k 300k 37.4k 500k
1.30k 48.7k 400k 30.1k 600k
1.30k 37.4k 500k 30.1k 600k
1.30k 30.1k 600k 24.9k 700k
1.30k 24.9k 700k 21.0k 800k
4.75k 27.4k 650k 16.9k 950k
4.75k 27.4k 650k 16.9k 950k
4.75k 27.4k 650k 16.9k 950k
6V to 9V
3V to 10.2V
4V to 12.6V
4V to 14.5V
6.3V to 18.7V Connect to BSTIN/BKLED– 2.2µF 1206 X7R 25V 2.2µF 1206 X7R 50V 24V to 32V
3V to 3.8V
3V to 5.5V
3.3V to 7V
4.1V to 10V
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 1206 X7R 16V
1µF 1206 X7R 16V
2.2µF 1206 X7R 10V
2.2µF 1206 X7R 10V
4V to 6V
6V to 9V
2.2µF 1206 X7R 16V 8V to 12V
2.2µF 1206 X7R 16V 12V to 16V
2.2µF 1206 X7R 25V 15V to 21V
2.2µF 1206 X7R 25V 18V to 24V
4.75k 19.6k 850k 15.8k
1M
5.5V to 12.5V Connect to BSTIN/BKLED–
4.75k 18.2k 900k 12.4k 1.2M
4.75k 16.9k 950k 14.0k 1.1M
4.75k 16.9k 950k 14.0k 1.1M
7.32k 27.4k 650k 16.9k 950k
7.32k 24.9k 700k 16.9k 950k
7.32k 24.9k 700k 16.9k 950k
7.32k 18.2k 900k 12.4k 1.2M
7.32k 18.2k 900k 14.0k 1.1M
7.32k 18.2k 900k 14.0k 1.1M
6.4V to 15V
9V to 20.8V
3V to 3.8V
3.3V to 5.7V
4V to 7.2V
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED– 2.2µF 1206 X7R 25V 2.2µF 1206 X7R 50V 24V to 32V
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
1µF 1206 X7R 10V
1µF 1206 X7R 10V
1µF 1206 X7R 10V
2.2µF 1206 X7R 10V
2.2µF 1206 X7R 10V
4V to 6V
6V to 9V
2.2µF 1206 X7R 16V 8V to 12V
5.2V to 10.4V Connect to BSTIN/BKLED– 2.2µF 1206 X7R 16V 2.2µF 1206 X7R 16V 12V to 16V
7V to 13V
Connect to BSTIN/BKLED– 2.2µF 1206 X7R 16V 4.7µF 1206 X7R 25V 15V to 21V
8.2V to 15.5V Connect to BSTIN/BKLED– 2.2µF 1206 X7R 16V 4.7µF 1206 X7R 25V 18V to 24V
11.8V to 21.2V Connect to BSTIN/BKLED– 2.2µF 1206 X7R 25V 4.7µF 1206 X7R 50V 24V to 32V
7.32k 16.9k 950k 15.8k
1M
3.3V to 3.5V
4V to 5.8V
5V to 7.6V
7V to 11V
Connect to BSTIN/BKLED– 1µF 1206 X7R 10V4 4.7µF 1206 X7R 10V
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
4V to 6V
6V to 9V
11.8k 27.4k 650k 16.9k 950k
11.8k 24.9k 700k 21.0k 800k
11.8k 24.9k 700k 22.6k 750k
11.8k 18.2k 900k 16.9k 950k
11.8k 18.2k 900k 16.9k 950k
11.8k 18.2k 900k 16.9k 950k
1µF 1206 X7R 10V
4.7µF 1206 X7R 10V
1µF 1206 X7R 10V
4.7µF 1206 X7R 16V 8V to 12V
Connect to BSTIN/BKLED– 2.2µF 1206 X7R 16V 4.7µF 1206 X7R 16V 12V to 16V
9.5V to 13.5V Connect to BSTIN/BKLED– 2.2µF 1206 X7R 16V 4.7µF 1206 X7R 25V 15V to 21V
11V to 16V
Connect to BSTIN/BKLED– 2.2µF 1206 X7R 16V 4.7µF 1206 X7R 25V 18V to 24V
16.5V to 21V Connect to BSTIN/BKLED– 2.2µF 1206 X7R 25V 4.7µF 1206 X7R 50V 24V to 32V
11.8k 16.9k 950k 15.8k
1M
5V to 5.8V
Connect to BSTIN/BKLED–
Connect to BSTIN/BKLED–
1µF 1206 X7R 10V
4.7µF 1206 X7R 10V
6V to 9V
Open 30.1k 600k 22.6k 750k
Open 30.1k 600k 24.9k 700k
Open 24.9k 700k 22.6k 750k
Open 21.0k 800k 19.6k 850k
Open 27.4k 650k 24.9k 700k
Open 33.2k 550k 30.1k 600k
6.4V to 7.7V
1µF 1206 X7R 10V
4.7µF 1206 X7R 16V 8V to 12V
1A
8.6V to 11.3V Connect to BSTIN/BKLED– 2.2µF 1206 X7R 16V 4.7µF 1206 X7R 16V 12V to 16V
11.3V to 13.8V Connect to BSTIN/BKLED– 2.2µF 1206 X7R 16V 4.7µF 1206 X7R 25V 15V to 21V
13.4V to 16.5V Connect to BSTIN/BKLED– 4.7µF 1206 X7R 25V 4.7µF 1206 X7R 25V 18V to 24V
20.5V to 22.5V Connect to BSTIN/BKLED– 4.7µF 1206 X7R 25V 4.7µF 1206 X7R 50V 24V to 32V
1A
1A
1A
1A
80421fb
20
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
Table 2. LTM8042 Recommended Values and Configuration for Buck Mode (TA = 25°C)
LED STRING
VOLTAGE
(LED+ TO
BSTIN/
CIN
COUT
LED
RT
f
VIN RANGE
(BSTOUT/BKIN)
(BSTOUT/BKIN
TO GND)
(BSTOUT/BKIN TO
STRING
(OPTI- (OPTI- RT
f
VCC
CVCC
BSTIN/BKLED–)
BKLED–) CURRENT RCTL MAL) MAL) (MIN) (MAX)
4.4V to 5.5V
6.8V to 14V
9.6V to 26V
3V to 30V 1µF 0805 X7R 50V
3V to 30V 1µF 0805 X7R 50V
3V to 30V 1µF 0805 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
1µF 1206 X7R 50V
2.2µF 1206 X7R 10V
2.2µF 1206 X7R 10V
2.2µF 1206 X7R 16V
2V to 4V
4V to 6V
6V to 9V
35mA
35mA
35mA
35mA
35mA
35mA
35mA
523 86.6k 250k 86.6k 250k
523 86.6k 250k 86.6k 250k
523 86.6k 250k 86.6k 250k
523 86.6k 250k 86.6k 250k
523 86.6k 250k 46.4k 420k
523 86.6k 250k 33.2k 550k
523 86.6k 250k 26.1k 670k
12.5V to 33V 3V to 30V 1µF 0805 X7R 50V
16.6V to 33V 3V to 30V 1µF 0805 X7R 50V
21.8V to 33V 3V to 30V 1µF 0805 X7R 50V
24.5V to 33V 3V to 30V 1µF 0805 X7R 50V
2.2µF 1210 X7R 16V 8V to 12V
2.2µF 1210 X7R 25V 12V to 16V
2.2µF 1210 X7R 25V 15V to 21V
2.2µF 1210 X7R 25V 18V to 24V
4.5V to 21V
3V to 30V 1µF 0805 X7R 50V
4.7µF 1206 X7R 10V
4.7µF 1206 X7R 10V
4.7µF 1210 X7R 16V
2V to 4V
4V to 6V
6V to 9V
100mA 1.30k 86.6k 250k 86.6k 250k
100mA 1.30k 86.6k 250k 86.6k 250k
100mA 1.30k 76.8k 275k 69.8k 300k
100mA 1.30k 69.8k 300k 48.7k 400k
6.8V to 33.8V 3V to 30V 1µF 0805 X7R 50V
9.9V to 33.5V 3V to 30V 1µF 0805 X7R 50V
13V to 33.4V 3V to 30V 1µF 0805 X7R 50V
17.2V to 33.1V 3V to 30V 1µF 0805 X7R 50V
4.7µF 1210 X7R 16V 8V to 12V
4.7µF 1210 X7R 25V 12V to 16V 100mA 1.30k 37.4k 500k 31.6k 575k
4.7µF 1210 X7R 25V 15V to 21V 100mA 1.30k 24.9k 700k 19.1k 870k
4.7µF 1210 X7R 25V 18V to 24V 100mA 1.30k 21.0k 800k 12.4k 1.2M
23V to 33V
26V to 33V
3V to 30V 1µF 0805 X7R 50V
3V to 30V 1µF 0805 X7R 50V
5.2V to 33.6V 3V to 30V 1µF 0805 X7R 50V
7V to 33.4V 3V to 30V 1µF 0805 X7R 50V
4.7µF 1206 X7R 10V
4.7µF 1206 X7R 10V
4.7µF 1210 X7R 16V
2V to 4V
4V to 6V
6V to 9V
350mA 4.75k 61.9k 330k 54.9k 365k
350mA 4.75k 30.1k 600k 24.9k 700k
350mA 4.75k 21.0k 800k 15.8k 1M
350mA 4.75k 12.4k 1.2M 8.25k 1.6M
10.5V to 33.3V 3V to 30V 1µF 0805 X7R 50V
14.5V to 33.2V 3V to 30V 1µF 0805 X7R 50V
19.2V to 33V 3V to 30V 1µF 0805 X7R 50V
4.7µF 1210 X7R 16V 8V to 12V
4.7µF 1210 X7R 25V 12V to 16V 350mA 4.75k 11.0k 1.3M 3.74k 2.5M
4.7µF 1210 X7R 25V 15V to 21V 350mA 4.75k 11.0k 1.3M 3.74k 2.5M
25V to 33V
4.9V to 33V
3V to 30V 1µF 0805 X7R 50V
3V to 30V 1µF 0805 X7R 50V
4.7µF 1206 X7R 10V
4.7µF 1206 X7R 10V
4.7µF 1210 X7R 16V
2V to 4V
4V to 6V
6V to 9V
500mA 7.32k 37.4k 500k 33.2k 550k
500mA 7.32k 21.0k 800k 18.2k 900k
500mA 7.32k 15.8k 1M 11.0k 1.3M
500mA 7.32k 15.8k 1M 7.50k 1.7M
7.3V to 33.2V 3V to 30V 1µF 0805 X7R 50V
10.7V to 33V 3V to 30V 1µF 0805 X7R 50V
14.1V to 32.8V 3V to 30V 1µF 0805 X7R 50V
18.5V to 32.5V 3V to 30V 1µF 0805 X7R 50V
24.3V to 32.5V 3V to 30V 1µF 0805 X7R 50V
4.7µF 1210 X7R 16V 8V to 12V
4.7µF 1210 X7R 25V 12V to 16V 500mA 7.32k 15.8k 1M 3.74 2.5M
4.7µF 1210 X7R 25V 15V to 21V 500mA 7.32k 15.8k 1M 3.74k 2.5M
5V to 33.2V
3V to 30V 1µF 0805 X7R 50V
4.7µF 1206 X7R 10V
4.7µF 1206 X7R 10V
4.7µF 1210 X7R 16V
2V to 4V
4V to 6V
6V to 9V
700mA 11.8k 33.2k 550k 30.1k 600k
700mA 11.8k 21.0k 800k 18.2k 900k
700mA 11.8k 15.8k 1M 11.0k 1.3M
700mA 11.8k 15.8k 1M 7.50k 1.7M
7.3V to 32.7V 3V to 30V 1µF 0805 X7R 50V
10.8V to 32.7V 3V to 30V 1µF 0805 X7R 50V
14.4V to 32.2V 3V to 30V 1µF 0805 X7R 50V
18.8V to 31.7V 3V to 30V 1µF 0805 X7R 50V
24.3V to 31.8V 3V to 30V 1µF 0805 X7R 50V
4.7µF 1210 X7R 16V 8V to 12V
4.7µF 1210 X7R 25V 12V to 16V 700mA 11.8k 15.8k 1M 3.74k 2.5M
4.7µF 1210 X7R 25V 15V to 21V 700mA 11.8k 15.8k 1M 3.74k 2.5M
1A
1A
1A
1A
1A
1A
5V to 32V
3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 50V 4.7µF 1206 X7R 10V
3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 50V 4.7µF 1206 X7R 10V
2V to 4V
4V to 6V
6V to 9V
Open 33.2k 550k 30.1k 600k
Open 21.0k 800k 16.9k 950k
Open 15.8k 1M 11.0k 1.3M
Open 15.8k 1M 7.50k 1.7M
Open 15.8k 1M 3.74k 2.5M
Open 15.8k 1M 3.74k 2.5M
7.2V to 32V
10.8V to 31V 3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 50V 4.7µF 1210 X7R 16V
14.3V to 30.5V 3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 50V 4.7µF 1210 X7R 16V 8V to 12V
18.9V to 30.5V 3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 50V 4.7µF 1210 X7R 25V 12V to 16V
24.6V to 30.5V 3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 50V 4.7µF 1210 X7R 25V 15V to 21V
80421fb
21
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
Table 3. LTM8042 Recommended Values and Configuration for Buck-Boost Mode (TA = 25°C)
LED
STRING
VIN
COUT1
(BSTOUT/BKIN
TO BSTIN/
BKLED–)
VOLTAGE
LED
RANGE
(BSTIN/
BKLED–)
CIN
COUT2
(BSTOUT/BKIN
TO GND)
(LED+ to STRING
BSTIN/ CURR-
RT
f
CVCC
(VCC to GND)
(BSTIN/BKLED–
TO GND)
(OPTI- (OPTI- RT
f
VCC
BKLED–)
2V to 4V
4V to 6V
6V to 9V
ENT RCTL MAL) MAL) (MIN) (MAX)
3V to 6V
3V to 14V
3V to 20V
3V to 21V
3V to 17.8V
3V to 13V
3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 10V 1µF 0805 X7R 10V 1µF 0805 X7R 10V
3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 16V 1µF 0805 X7R 10V 1µF 0805 X7R 10V
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 10V 1µF 0805 X7R 10V
35mA
35mA
35mA
35mA
523 86.6k 250k 86.6k 250k
523 86.6k 250k 86.6k 250k
523 86.6k 250k 86.6k 250k
523 86.6k 250k 57.6k 350k
523 48.7k 400k 27.4k 650k
523 37.4k 500k 10.0k 1.4M
523 22.6k 750k 3.74k 2.5M
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 16V 1µF 0805 X7R 16V 8V to 12V
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 16V 1µF 1206 X7R 25V 12V to 16V 35mA
3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 16V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 15V to 21V 35mA
3.5V to 10.1V 3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 16V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 18V to 24V 35mA
3V to 21V
3V to 22.8V
3V to 23.4V
3V to 21.8V
3V to 17.9V
3V to 12.6V
3.7V to 9.7V
3V to 28V
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 10V 1µF 0805 X7R 10V
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 10V 1µF 0805 X7R 10V
2V to 4V
4V to 6V
6V to 9V
100mA 1.30k 86.6k 250k 69.8k 300k
100mA 1.30k 48.7k 400k 43.2k 450k
100mA 1.30k 37.4k 500k 30.1k 600k
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 16V 1µF 1206 X7R 25V 8V to 12V 100mA 1.30k 21.0k 800k 16.9k 950k
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 16V 1µF 1206 X7R 25V 12V to 16V 100mA 1.30k 19.6k 850k 11.0k 1.3M
3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 16V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 15V to 21V 100mA 1.30k 19.6k 850k 4.02k 2.4M
3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 10V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 18V to 24V 100mA 1.30k 19.6k 850k 3.74k 2.5M
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
2V to 4V
4V to 6V
6V to 9V
350mA 4.75k 43.2k 450k 37.4k 500k
350mA 4.75k 33.2k 550k 24.9k 700k
350mA 4.75k 24.9k 700k 10.7k 1.35M
3V to 27.5V
4.5V to 24.5V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
5.5V to 20.7V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 16V 1µF 1206 X7R 25V 8V to 12V 350mA 4.75k 15.8k
7V to 17.1V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 16V 1µF 1206 X7R 25V 12V to 16V 350mA 4.75k 15.8k
1M
1M
6.19k 1.9M
3.74k 2.5M
8.2V to 11.4V 3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 16V 4.7µF 1210 X7R 25V 1µF 1206 X7R 25V 15V to 21V 350mA 4.75k 18.2k 900k 3.74k 2.5M
3V to 23V
4.5V to 27V
6V to 24V
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
2V to 4V
4V to 6V
6V to 9V
500mA 7.32k 27.4k 650k 24.9k 700k
500mA 7.32k 21.0k 800k 19.6k 850k
500mA 7.32k 15.8k
1M
1M
1M
10.0k 1.4M
6.34k 1.85M
3.74k 2.5M
7.3V to 20.3V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 16V 1µF 1206 X7R 25V 8V to 12V 500mA 7.32k 15.8k
9.4V to 15V
3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 16V 2.2µF 1206 X7R 16V 1µF 1206 X7R 25V 12V to 16V 500mA 7.32k 15.8k
4.2V to 23.8V 3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 25V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
2V to 4V
4V to 6V
6V to 9V
700mA 11.8k 24.9k 700k 22.6k 750k
700mA 11.8k 16.9k 950k 15.8k 1M
700mA 11.8k 16.9k 950k 9.09k 1.5M
4.7V to 27V
6.1V to 23V
7.3V to 20V
3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 50V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 25V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V
3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 25V 2.2µF 1206 X7R 16V 1µF 1206 X7R 25V 8V to 12V 700mA 11.8k 16.9k 950k 6.19k 1.9M
1M 3.74k 2.5M
10.5V to 16.5V 3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 25V 4.7µF 1210 X7R 16V 1µF 1206 X7R 25V 12V to 16V 700mA 11.8k 15.8k
4.7V to 28.5V 3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 50V 4.7µF 1206 X7R 10V 1µF 0805 X7R 10V
6.7V to 26.8V 3V to 30V 1µF 0805 X7R 50V 2.2µF 1206 X7R 50V 4.7µF 1206 X7R 10V 1µF 0805 X7R 10V
2V to 4V
4V to 6V
6V to 9V
Open 24.9k 700k 22.6k 750k
Open 22.6k 750k 16.9k 950k
Open 22.6k 750k 10.0k 1.4M
1A
1A
1A
1A
9V to 23.5V
3V to 30V 1µF 0805 X7R 50V 4.7µF 1210 X7R 25V 4.7µF 1206 X7R 10V 1µF 0805 X7R 10V
13.5V to 20V
3V to 30V 1µF 0805 X7R 50V 4.7µF 1210 X7R 25V 4.7µF 1210 X7R 16V 1µF 1206 X7R 25V 8V to 12V
Open 22.6k 750k 5.76k
2M
80421fb
22
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
Table 4. LTM8042-1 Recommended Values and Configuration for Boost (TA = 25°C)
LED
V
STRING
IN
RANGE
(BSTIN/
C
C
VOLTAGE
LED
RT
(OPTI- (OPTI- RT
MAL) MAL) (MIN) (MAX)
f
IN
OUT
–
+
(BSTIN/BKLED
TO GND)
(BSTOUT/BKIN
TO GND)
(LED TO STRING
f
–
BKLED )
V
GND)
CURRENT
35mA
35mA
35mA
35mA
35mA
35mA
35mA
R
CTL
CC
1V to 3.3V
1.2V to 5V
1.6V to 6V
2.2V to 9.2V
2.7V to 10V
3V to 30V
3V to 30V
3V to 30V
3V to 30V
3V to 30V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 16V
1µF 0805 X7R 16V
1µF 0805 X7R 16V
1µF 0805 X7R 10V
1µF 0805 X7R 10V
1µF 0805 X7R 16V
4V to 6V
6V to 9V
8V to 12V
1.27k 86.6k 250k 69.8k 300k
1.27k 76.8k 275k 61.9k 330k
1.27k 69.8k 300k 57.6k 350k
1.27k 48.7k 400k 37.4k 500k
1.27k 37.4k 500k 30.1k 600k
1.27k 33.2k 550k 27.4k 650k
1.27k 33.2k 550k 27.4k 650k
1µF 0805 X7R 16V 12V to 16V
1µF 0805 X7R 25V 15V to 21V
1µF 0805 X7R 25V 18V to 24V
1µF 0805 X7R 50V 24V to 32V
–
–
3V to 12.8V Connect to BSTIN/BKLED
3.7V to 14.7V Connect to BSTIN/BKLED
1.1V to 3.8V
1.5V to 5.6V
2.4V to 7.1V
3V to 30V
3V to 30V
3V to 30V
1µF 0805 X7R 10V 2.2µF 1206 X7R 10V 4V to 6V
1µF 0805 X7R 16V 2.2µF 1206 X7R 10V 6V to 9V
2.2µF 1206 X7R 10V 2.2µF 1206 X7R 16V 8V to 12V
100mA 3.40k 86.6k 250k 37.4k 500k
100mA 3.40k 76.8k 275k 37.4k 500k
100mA 3.40k 69.8k 300k 37.4k 500k
–
3.1V to 10.4V Connect to BSTIN/BKLED 2.2µF 1206 X7R 16V 2.2µF 1206 X7R 16V 12V to 16V 100mA 3.40k 48.7k 400k 30.1k 600k
–
4V to 12V
Connect to BSTIN/BKLED 2.2µF 1206 X7R 16V 2.2µF 1206 X7R 25V 15V to 21V 100mA 3.40k 37.4k 500k 30.1k 600k
–
4.9V to 14.9V Connect to BSTIN/BKLED
6.1V to 18.8V Connect to BSTIN/BKLED
1µF 0805 X7R 16V 2.2µF 1206 X7R 25V 18V to 24V 100mA 3.40k 30.1k 600k 24.9k 700k
1µF 0805 X7R 25V 2.2µF 1206 X7R 50V 24V to 32V 100mA 3.40k 24.9k 700k 21.0k 800k
–
2.4V to 3.8V
2.8V to 5.3V
3.2V to 7V
3V to 30V
3V to 30V
1µF 0805 X7R 10V 4.7µF 0805 X7R 10V 4V to 6V
1µF 0805 X7R 10V 2.2µF 1206 X7R 10V 6V to 9V
1µF 0805 X7R 10V 2.2µF 1206 X7R 16V 8V to 12V
350mA 19.6k 27.4k 650k 16.9k 950k
350mA 19.6k 27.4k 650k 16.9k 950k
350mA 19.6k 27.4k 650k 16.9k 950k
–
–
–
–
–
Connect to BSTIN/BKLED
4.1V to 10V Connect to BSTIN/BKLED
4.8V to 12.3V Connect to BSTIN/BKLED
5.8V to 15V Connect to BSTIN/BKLED
1µF 1206 X7R 10V 2.2µF 1206 X7R 16V 12V to 16V 350mA 19.6k 19.6k 850k 15.8k 1M
1µF 1206 X7R 16V 2.2µF 1206 X7R 25V 15V to 21V 350mA 19.6k 18.2k 900k 12.4k 1.2M
1µF 1206 X7R 16V 2.2µF 1206 X7R 25V 18V to 24V 350mA 19.6k 16.9k 950k 14.0k 1.1M
8.5V to 20.8V Connect to BSTIN/BKLED 2.2µF 1206 X7R 25V 2.2µF 1206 X7R 50V 24V to 32V 350mA 19.6k 16.9k 950k 14.0k 1.1M
80421fb
23
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
Table 5. LTM8042-1 Recommended Values and Configuration for Buck Mode (TA = 25°C)
LED
STRING
VOLTAGE
+
V
RANGE
C
C
OUT
(LED TO
LED
R
f
IN
IN
(BSTOUT/
BKIN)
(BSTOUT/BKIN
TO GND)
(BSTOUT/BKIN TO
BSTIN/
STRING
(OPTI- (OPTI- RT
f
–
–
V
CV
BSTIN/BKLED )
BKLED ) CURRENT R
MAL) MAL) (MIN) (MAX)
CC
CC
CTL
4.3V to 8.3V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1206 X7R 10V 2V to 4V
6.6V to 20V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1206 X7R 10V 4V to 6V
35mA 1.27k 86.6k 250k 86.6k 250k
35mA 1.27k 86.6k 250k 86.6k 250k
35mA 1.27k 86.6k 250k 86.6k 250k
35mA 1.27k 86.6k 250k 86.6k 250k
9.5V to 31.5V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1206 X7R 16V 6V to 9V
12.5V to 33V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1210 X7R 16V 8V to 12V
16.6V to 33.2V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1210 X7R 25V 12V to 16V 35mA 1.27k 86.6k 250k 46.4k 420k
21.8V to 33.6V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1210 X7R 25V 15V to 21V 35mA 1.27k 86.6k 250k 33.2k 550k
24.4V to 33.1V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1210 X7R 25V 18V to 24V 35mA 1.27k 86.6k 250k 26.1k 670k
4.3V to 19.5V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1206 X7R 10V 2V to 4V
6.5V to 33.8V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1206 X7R 10V 4V to 6V
9.6V to 34.5V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 16V 6V to 9V
100mA 3.40k 86.6k 250k 86.6k 250k
100mA 3.40k 86.6k 250k 86.6k 250k
100mA 3.40k 76.8k 275k 57.6k 350k
12.6V to 34.4V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 16V 8V to 12V 100mA 3.40k 69.8k 300k 48.7k 400k
17V to 34.5V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 25V 12V to 16V 100mA 3.40k 37.4k 500k 31.6k 575k
22.8V to 34.5V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 25V 15V to 21V 100mA 3.40k 24.9k 700k 19.1k 870k
26.2V to 34.4V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 25V 18V to 24V 100mA 3.40k 21.0k 800k 12.4k 1.2M
4.6V to 34.3V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1206 X7R 10V 2V to 4V
6.7V to 34.3V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1206 X7R 10V 4V to 6V
10.3V to 34.3V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 16V 6V to 9V
350mA 19.6k 61.9k 330k 54.9k 365k
350mA 19.6k 30.1k 600k 24.9k 700k
350mA 19.6k 21.0k 800k 15.8k 1M
13.7V to 34.5V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 16V 8V to 12V 350mA 19.6k 19.6k 850k 8.25k 1.6M
18.6V to 34.6V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 25V 12V to 16V 350mA 19.6k 14.0k 1.1M 3.74k 2.5M
24.1V to 34.3V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 25V 15V to 21V 350mA 19.6k 15.8k 1M 3.74k 2.5M
27.3V to 32.8V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 4.7µF 1210 X7R 25V 18V to 24V 350mA 19.6k 15.8k 1M 3.74k 2.5M
80421fb
24
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
Table 6. LTM8042-1 Recommended Values and Configuration for Buck-Boost Mode (TA = 25°C)
LED
STRING
C
VOLTAGE LED
OUT1
+
V
RANGE
C
(BSTOUT/BKIN
TO BSTIN/
C
OUT2
(LED TO STRING
RT
(OPTI- (OPTI- RT
MAL) MAL) (MIN) (MAX)
f
IN
IN
–
(BSTIN/
CV
CC
(BSTIN/BKLED
TO GND)
(BSTOUT/BKIN BSTIN/
CUR-
f
CC
–
–
–
BKLED )
V
CC
(V TO GND)
BKLED )
TO GND)
BKLED ) RENT
R
CTL
1V to 9.5V 3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 10V 1µF 0805 X7R 10V 1µF 0805 X7R 10V 2V to 4V
1.1V to 21V 3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 16V 1µF 0805 X7R 10V 1µF 0805 X7R 10V 4V to 6V
1.3V to 24V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 10V 1µF 0805 X7R 10V 6V to 9V
35mA 1.27k 86.6k 250k 86.6k 250k
35mA 1.27k 86.6k 250k 86.6k 250k
35mA 1.27k 86.6k 250k 86.6k 250k
1.5V to 20.8V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 16V 1µF 0805 X7R 16V 8V to 12V 35mA 1.27k 86.6k 250k 43.2k 450k
2.2V to 16.9V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 16V 1µF 1206 X7R 25V 12V to 16V 35mA 1.27k 48.7k 400k 30.1k 600k
3V to 12V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 15V to 21V 35mA 1.27k 37.4k 500k 10.0k 1.4M
3.8V to 9V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 18V to 24V 35mA 1.27k 22.6k 750k 3.74k 2.5M
1.1V to 24V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V 2V to 4V 100mA 3.40k 86.6k 250k 69.8k 300k
1.3V to 27V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 10V 1µF 0805 X7R 10V 4V to 6V 100mA 3.40k 48.7k 400k 43.2k 450k
1.6V to 24V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 10V 1µF 0805 X7R 10V 6V to 9V 100mA 3.40k 37.4k 500k 33.2k 550k
1.9V to 21.5V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 16V 1µF 0805 X7R 16V 8V to 12V 100mA 3.40k 21.0k 800k 19.6k 850k
2.5V to 17V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 1µF 0805 X7R 16V 1µF 1206 X7R 25V 12V to 16V 100mA 3.40k 19.6k 850k 8.25k 1.6M
3V to 12V 3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 16V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 15V to 21V 100mA 3.40k 19.6k 850k 3.74k 2.5M
3.7V to 9V 3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 10V 1µF 1206 X7R 25V 1µF 1206 X7R 25V 18V to 24V 100mA 3.40k 15.8k
1M 3.74k 2.5M
2.2V to 29V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V 2V to 4V 350mA 19.6k 43.2k 450k 37.4k 500k
2.7V to 27.5V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 50V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V 4V to 6V 350mA 19.6k 27.4k 650k 18.2k 900k
3.7V to 23.8V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 10V 1µF 0805 X7R 10V 6V to 9V 350mA 19.6k 18.2k 900k 9.09k 1.5M
3.8V to 20.2V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 16V 1µF 0805 X7R 16V 8V to 12V 350mA 19.6k 14.0k 1.1M 6.19k 1.9M
5.3V to 15.2V 3V to 30V 1µF 0805 X7R 50V 1µF 1206 X7R 25V 2.2µF 1206 X7R 16V 1µF 1206 X7R 25V 12V to 16V 350mA 19.6k 14.0k 1.1M 3.74k 2.5M
7.4V to 9.3V 3V to 30V 1µF 0805 X7R 50V 1µF 0805 X7R 16V 2.2µF 1206 X7R 16V 1µF 1206 X7R 25V 15V to 21V 350mA 19.6k 18.2k 900k 3.74k 2.5M
80421fb
25
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
Thermal Considerations
Whilethemeaningofeachofthesecoefficientsmayseemto
beintuitive,JEDEChasdefinedeachtoavoidconfusionand
inconsistency. These definitions are given in JESD 51-12,
and are quoted or paraphrased in the following:
The LTM8042/LTM8042-1 output current may need to be
derated if it is required to operate in a high ambient tem-
perature or deliver a large amount of continuous power.
The amount of current derating is dependent upon the
inputvoltage,outputpowerandambienttemperature.The
temperature rise curves given in the Typical Performance
Characteristicssectioncanbeusedasaguide.Thesecurves
weregenerated by an LTM8042/LTM8042-1 mounted to a
1. θ is the natural convection junction-to-ambient air
JA
thermal resistance measured in a one cubic foot sealed
enclosure.Thisenvironmentissometimesreferredtoas
“still air” although natural convection causes the air to
move.Thisvalueisdeterminedwiththepartmountedto
a JESD 51-9 defined test board, which does not reflect
an actual application or viable operating condition.
2
51cm 4-layer FR4 printed circuit board. Boards of other
sizesandlayercountcanexhibitdifferentthermalbehavior,
soitisin-cumbentupontheusertoverifyproperoperation
over the intended system’s line, load and environmental
operating conditions.
2. θ
is the junction-to-board thermal resistance
JCBOTTOM
with all of the component power dissipation flowing
through the bottom of the package. In the typical
µModule regulator, the bulk of the heat flows out the
bottom of the package, but there is always heat flow
out into the ambient environment. As a result, this
thermal resistance value may be useful for comparing
packages but the test conditions don’t generally match
the user’s application.
ThethermalresistancenumberslistedinthePinConfigura-
tion section of the data sheet are based on modeling the
µModule package mounted on a test board specified per
JESD51-9 (“Test Boards for Area Array Surface Mount
Package Thermal Measurements”). The thermal coef-
ficients provided are based on JESD 51-12 (“Guidelines
for Reporting and Using Electronic Package Thermal
Information”).
3. θ
is determined with nearly all of the component
JCTOP
power dissipation flowing through the top of the
package. As the electrical connections of the typical
µModule regulator are on the bottom of the package,
it is rare for an application to operate such that most of
the heat flows from the junction to the top of the part.
For increased accuracy and fidelity to the actual applica-
tion, many designers use finite element analysis (FEA) to
predict thermal performance. To that end, the Pin Con-
figuration section of the data sheet typically gives four
thermal coefficients:
As in the case of θ
, this value may be useful
JCBOTTOM
for comparing packages but the test conditions don’t
generally match the user’s application.
1. θ : thermal resistance from junction to ambient.
JA
2. θ
: thermal resistance from junction to the
JCBOTTOM
bottom of the product case.
4. θ is the junction-to-board thermal resistance where
JB
almost all of the heat flows through the bottom of the
3. θ : thermal resistance from junction to top of the
µModule regulator and into the board, and is really the
JCTOP
product case.
sum of the θ
and the thermal resistance of
JCBOTTOM
the bottom of the part through the solder joints and
throughaportionoftheboard.Theboardtemperatureis
measured a specified distance from the package, using
a two sided, two layer board. This board is described
in JESD 51-9.
4. θ : thermal resistance from junction to the printed
JB
circuit board.
80421fb
26
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
APPLICATIONS INFORMATION
The most appropriate way to use the coefficients is when
running a detailed thermal analysis, such as FEA, which
considers all of the thermal resistances simultaneously.
None of them can be individually used to accurately pre-
dict the thermal performance of the product, so it would
be inappropriate to attempt to use any one coefficient to
correlate to the junction temperature versus load graphs
given in the LTM8042/LTM8042-1 data sheet.
The die temperature of the LTM8042/LTM8042-1 must be
lower than the maximum rating of 125°C, so care should
be taken in the layout of the circuit to ensure good heat
sinking of the LTM8042/LTM8042-1. The bulk of the
heat flow out of the LTM8042/LTM8042-1 is through the
bottom of the module and the LGA pads into the printed
circuit board. Consequently, a poor printed circuit board
design can cause excessive heating, resulting in impaired
performance or reliability. Please refer to the PCB Layout
section for printed circuit board design suggestions.
A graphical representation of these thermal resistances
is given in Figure 5.
The blue resistances are contained within the µModule
regulator, and the green are outside.
JUNCTION-TO-AMBIENT RESISTANCE (JESD 51-9 DEFINED BOARD)
JUNCTION-TO-CASE (TOP)
RESISTANCE
CASE (TOP)-TO-AMBIENT
RESISTANCE
JUNCTION-TO-BOARD RESISTANCE
JUNCTION
A
t
JUNCTION-TO-CASE
(BOTTOM) RESISTANCE
CASE (BOTTOM)-TO-BOARD
BOARD-TO-AMBIENT
RESISTANCE
RESISTANCE
80421 F05
µMODULE DEVICE
Figure 5
TYPICAL APPLICATIONS
Boost Operation, Driving 6 White LEDs at 1A
V
IN
+
LTM8042
V
LED
CC
UP TO 20.6V
11.6V TO 19V
RUN
TG
–
BSTIN/BKLED
PWM
SYNC
TGEN
BSTOUT/BKIN
1A
SS
RT
4.7µF
GND CTL
4.7µF
22.6k
= 750kHz
f
SW
80421 TA02
80421fb
27
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
TYPICAL APPLICATIONS
Buck-Boost Mode, Driving 5 White LEDs at 500mA with PWM Dimming
Si2319DS
LTM8042
V
IN
+
V
CC
LED
7V TO 17.5V
UP TO 16.3V
500mA
RUN
PWM
TGEN
SYNC
SS
TG
BSTOUT/BKIN
–
BSTIN/BKLED
1µF
RT
GND CTL
2.2µF
1µF
19.6k
= 850kHz
7.32k
f
SW
80421 TA03
Buck Mode, Driving 4 White LEDs at 1A
LTM8042
+
V
IN
V
LED
CC
UP TO 13.9V
19V TO 30V
RUN
PWM
SYNC
TGEN
SS
TG
BSTOUT/BKIN
–
BSTIN/BKLED
1A
2.2µF
4.7µF
1µF
RT
GND CTL
= 1MHz
15.8k
f
SW
80421 TA04
Boost Operation, Driving 9 White LEDs at 100mA
Si2319DS
UP TO 29V
V
IN
LTM8042-1
–
+
V
LED
CC
6V TO 22V
RUN
TG
BSTIN/BKLED
100mA
PWM
TGEN
SYNC
BSTOUT/BKIN
SS
RT
2.2µF
GND CTL
2.2µF
24.9k
= 700kHz
3.4k
f
SW
80421 TA05
80421fb
28
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
PACKAGE DESCRIPTION
Pin Assignment Table
(Arranged by Pin Number)
PIN
A1
A2
A3
A4
A5
A6
A7
NAME
GND
GND
GND
GND
GND
PIN
B1
B2
B3
B4
B5
B6
B7
NAME
GND
GND
GND
GND
GND
PIN
C1
C2
C3
C4
C5
C6
C7
NAME
GND
PIN
D1
D2
D3
D4
D5
D6
D7
NAME
GND
PIN
E1
E2
E3
E4
E5
E6
E7
NAME
GND
GND
GND
GND
GND
GND
GND
PIN
F1
F2
F3
F4
F5
F6
F7
NAME
RUN
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
BSTIN/BKLED–
BSTIN/BKLED–
BSTIN/BKLED–
BSTIN/BKLED–
BSTIN/BKLED–
BSTIN/BKLED–
V
CC
V
CC
V
V
CC
CC
PIN
G1
G2
G3
G4
NAME
SYNC
GND
PIN
H1
H2
H3
H4
H5
H6
H7
NAME
RT
PIN
J1
J2
J3
J4
J5
J6
J7
NAME
SS
PIN
K1
K2
K3
K4
K5
K6
K7
NAME
PWM
GND
PIN
L1
L2
L3
L4
L5
L6
L7
NAME
GND
GND
GND
CTL
GND
GND
GND
GND
TGEN
GND
GND
GND
GND
GND
G5 BSTOUT/BKIN
G6 BSTOUT/BKIN
G7 BSTOUT/BKIN
BSTOUT/BKIN
BSTOUT/BKIN
BSTOUT/BKIN
BSTOUT/BKIN
BSTOUT/BKIN
TG
LED+
LED+
LED+
LED+
LED+
LED+
PACKAGE PHOTOGRAPH
80421fb
29
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
PACKAGE DESCRIPTION
Z
/ / b b b
Z
3 . 8 1 0
2 . 5 4 0
1 . 2 7 0
0 . 0 0 0
1 . 2 7 0
2 . 5 4 0
3 . 8 1 0
1 . 5 8 7 5
0 . 9 5 2 5
80421fb
30
For more information www.linear.com/LTM8042
LTM8042/LTM8042-1
REVISION HISTORY
REV
DATE
01/11 Updated features.
Updated I conditions in the Electrical Characteristics section.
DESCRIPTION
PAGE NUMBER
A
1
3
LED
Updated text in the Operation section.
Updated text in the Setting the Switching Frequency section.
11/14 Corrected Top Mark for LTM8042-1
15
16
2
B
80421fb
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.
31
LTM8042/LTM8042-1
TYPICAL APPLICATION
Boost Operation, Driving 9 Red LEDs at 350mA with Analog Dimming
UP TO 28V
V
IN
V
CC
LTM8042
–
7V TO 24.8V
+
LED
RUN
TG
BSTIN/BKLED
BSTOUT/BKIN
PWM
SYNC
TGEN
SS
350mA
2.2µF
CTL GND RT
2.2µF
ANALOG
CONTROL
VOLTAGE
19.6k
= 850kHz
f
SW
80421 TA06
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTM8040
36V, 1A, µModule LED Driver and Current Source
4V ≤ V ≤ 36V; Open LED and Short-Circuit Protection,
IN
9mm × 15mm × 4.32mm LGA Package
LTM8032
LTM4607
EMC 36V, 2A, µModule Regulator
Buck-Boost µModule Regulator
EN55022 Class B Compliant; 0.8V ≤ V
≤ 10V
OUT
4.5V ≤ V ≤ 36V; 0.8V ≤ V
≤ 25V, 15mm × 15mm × 2.8mm
IN
OUT
80421fb
LT 1114 REV B • PRINTED IN USA
32 LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
●
●
LINEAR TECHNOLOGY CORPORATION 2010
(408)432-1900 FAX: (408) 434-0507 www.linear.com/LTM8042
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