LTM8042/LTM8042-1
µModule Boost LED Driver
and Current Source
FEATURES
n
n
n
DESCRIPTION
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
much as 3000:1 LED dimming, while 10:1 analog dimming
can be accomplished by a single resistor or analog voltage
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.
# WHITE LEDS
6
7
8
9
LED CURRENT
1A
350mA
1A
350mA
12V
IN
LTM8042
LTM8042-1
LTM8042
LTM8042-1
24V
IN
n
n
n
n
n
n
True Color PWM™ with 3000:1 Dimming Ratio
Operates in Boost, Buck Mode or Buck-Boost Mode
Wide Input Voltage Range:
Operation from 3V to 30V
Transient Protection to 40V
Gate Driver for Optional PWM Dimming with
P-channel MOSFET
Adjustable Frequency: 250kHz to 2MHz
Constant-Current and Constant-Voltage Regulation
Low Shutdown Current: <1μA
RoHS Compliant Package with Gold Pad Finish
Tiny, Low Profile (9mm
×
15mm
×
2.82mm)
Surface Mount LGA Package
APPLICATIONS
n
n
n
n
Display Backlighting
Automotive and Avionic Lighting
Illumination
Scanners
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.
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.
TYPICAL APPLICATION
µModule Boost LED Driver, Driving 8 White LEDs at 1A
UP TO 26.8V
V
IN
16V TO 26V
V
CC
RUN
BSTIN/BKLED
–
PWM
SYNC
TGEN
4.7µF
SS
RT
GND CTL
33.2k
f
SW
= 550kHz
4.7µF
LTM8042
LED
+
EFFICIENCY (%)
TG
97
96
95
94
93
92
91
90
89
88
87
16 17 18 19 20 21 22 23 24 25 26
V
IN
(V)
80421 TA01b
Efficiency vs V
IN
BSTOUT/BKIN
1A
80421 TA01a
80421fb
For more information
www.linear.com/LTM8042
1
LTM8042/LTM8042-1
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
BSTIN/BKLED
–
7
V
CC
6
5
4
3
2
1
A
B
C
D
E
F
G
H
J
K
SS PWM
L
BANK 1
GND
TGEN
CTL
BANK 2
BANK 3
BANK 4
BSTOUT/BKIN
TG
BANK 5
LED
+
V
CC
, RUN, PWM, TGEN, BSTIN/BKLED
–
...................40V
BSTOUT/BKIN, LED
+
................................................43V
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
RUN SYNC RT
LGA PACKAGE
77-LEAD (15mm
×
9mm
×
2.82mm)
T
JMAX
= 125°C,
θ
JA
= 15.7°C/W,
θ
JCtop
= 13.6°C/W,
θ
JCbottom
= 4.5°C/W,
θ
JB
= 9.4°C/W
θ
VALUES DETERMINED PER JESD 51-12
WEIGHT = 1.1g
ORDER INFORMATION
PART MARKING*
PART NUMBER
LTM8042EV#PBF
LTM8042IV#PBF
LTM8042EV-1#PBF
LTM8042IV-1#PBF
PAD OR BALL FINISH
Au (RoHS)
Au (RoHS)
Au (RoHS)
Au (RoHS)
DEVICE
LTM8042V
LTM8042V
LTM8042V-1
LTM8042V-1
FINISH CODE
e4
e4
e4
e4
PACKAGE TYPE
LGA
LGA
LGA
LGA
MSL RATING
3
3
3
3
TEMPERATURE RANGE
(Note 4)
–40°C
to 125°C
–40°C
to 125°C
–40°C
to 125°C
–40°C
to 125°C
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.
• Terminal Finish Part Marking:
www.linear.com/leadfree
• 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
80421fb
2
For more information
www.linear.com/LTM8042
LTM8042/LTM8042-1
ELECTRICAL CHARACTERISTICS
SYMBOL
V
CC(MIN)
I
LED
PARAMETER
Minimum Input DC Voltage
LTM8042 LED Current
LTM8042-1 LED Current
V
CLAMP
∆I
OUT
/I
OUT
I
QVCC
f
SW
I
SS
f
SYNC
I
SYNC
V
SYNC(IL)
V
SYNC(IH)
I
CTL
V
RUN(IH)
V
RUN(IL)
I
RUN
V
PWM(IH)
V
PWM(IL)
I
PWM
V
TG(OH)
V
TG(OL)
V
TGEN(IH)
V
TGEN(IL)
I
TGEN
Open LED Clamp Voltage
Output Current Line Regulation
V
CC
Supply Current
Switching Frequency
CTL Open
R
CTL
= 6.81k
CTL Open
R
CTL
= 6.81k
Boost Mode, LED
+
Open
LTM8042, 6V < BSTOUT/BKIN < 30V
LTM8042-1, 6V < BSTOUT/BKIN < 30V
PWM = 0V
RUN = 0V
RT = 90.9k
RT = 22.1k
RT = 6.04k
SS = 0.5V, Out of Pin
V
SYNC
= 2V
1.5
CTL = 0V, Flows Out of Pin
1.5
0.4
60
1.5
0.4
60
Relative to LED
+
, 100k from LED
+
to TG
Relative to LED
+
, 100k from LED
+
to TG
PWM = 0V
1.5
0.4
100
200
0
–7
120
100
100
0.22
0.68
1.7
6
0.3
60
0.4
The
l
denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V, buck mode with 4Ω load.
CONDITIONS
l
MIN
3
0.9
0.45
0.34
0.17
TYP
MAX
1.05
0.55
0.39
0.20
UNITS
V
A
A
A
A
V
%
%
0.5
36
0.5
0.5
4.2
0.1
0.25
0.8
2
9
1
0.27
0.92
2.3
12
2.5
mA
µA
MHz
MHz
MHz
µA
MHz
µA
V
V
µA
V
V
µA
V
V
µA
V
V
V
V
µA
Soft-Start Pin Current
Synchronization Frequency Range
SYNC Pull-Down Current (Into the Pin)
SYNC Input Low
SYNC Input High
CTL Input Bias Current
RUN Input Voltage High
RUN Input Voltage Low
RUN Pin Bias Current
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
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.
Note 2:
Absolute maximum voltage at V
CC
, RUN, PWM, TGEN, BSTIN/
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.
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.
80421fb
For more information
www.linear.com/LTM8042
3
LTM8042/LTM8042-1
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042
Efficiency vs V
IN
, Boost Operation,
6.8V at 1A LED String
90
89
88
EFFICIENCY (%)
EFFICIENCY (%)
87
86
85
84
83
82
81
80
4
5
V
IN
(V)
6
80421 G01
T
A
= 25°C, unless otherwise noted.
Efficiency vs V
IN
, Boost Operation,
13.4V at 1A LED String
95
94
93
EFFICIENCY (%)
92
91
90
89
88
87
86
Efficiency vs V
IN
, Boost Operation,
10.1V at 1A LED String
94
92
90
88
86
84
82
80
5
6
7
V
IN
(V)
80421 G02
8
9
10
85
7
8
9
10
V
IN
(V)
11
12
13
80421 G03
Efficiency vs V
IN
, Boost Operation,
16.7V at 1A LED String
94
92
EFFICIENCY (%)
EFFICIENCY (%)
90
88
86
84
82
80
8
9
10
11
12 13
V
IN
(V)
14
15
16
97
95
93
91
89
87
85
83
Efficiency vs V
IN
, Boost Operation,
20.1V at 1A LED String
97
95
93
EFFICIENCY (%)
91
89
87
85
11
12
13
14
15 16
V
IN
(V)
17
18
19
83
Efficiency vs V
IN
, Boost Operation,
23.4V at 1A LED String
12 13 14 15 16 17 18 19 20 21 22
V
IN
(V)
80421 G06
80421 G04
80421 G05
Efficiency vs V
IN
, Boost Operation,
26.8V at 1A LED String
97
96
95
EFFICIENCY (%)
EFFICIENCY (%)
94
93
92
91
90
89
88
87
16 17 18 19 20 21 22 23 24 25 26
V
IN
(V)
80421 G07
Efficiency vs V
IN
, Buck Mode,
3.5V at 1A LED String
89
87
EFFICIENCY (%)
4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34
V
IN
(V)
80421 G08
Efficiency vs V
IN
, Buck Mode,
6.8V at 1A LED String
94
92
90
88
86
84
82
80
8 10 12 14 16 18 20 22 24 26 28 30 32 34
V
IN
(V)
80421 G09
85
83
81
79
77
75
80421fb
4
For more information
www.linear.com/LTM8042
LTM8042/LTM8042-1
TYPICAL PERFORMANCE CHARACTERISTICS
LTM8042
Efficiency vs V
IN
, Buck Mode,
10.1V at 1A LED String
95
94
93
EFFICIENCY (%)
92
EFFICIENCY (%)
91
90
89
88
87
86
85
12 14 16 18 20 22 24 26 28 30 32 34
V
IN
(V)
80421 G10
T
A
= 25°C, unless otherwise noted.
Efficiency vs V
IN
, Buck Mode,
16.7V at 1A LED String
97
96
95
EFFICIENCY (%)
94
93
92
91
90
89
88
Efficiency vs V
IN
, Buck Mode,
13.4V at 1A LED String
97
96
95
94
93
92
91
90
89
88
87
15 17 19 21 23 25 27 29 31 33
V
IN
(V)
80421 G11
87
19
21
23
25
27
V
IN
(V)
29
31
33
80421 G12
Efficiency vs V
IN
, Buck-Boost
Mode, 3.6V at 1A LED String
85
80
85
EFFICIENCY (%)
EFFICIENCY (%)
90
Efficiency vs V
IN
, Buck-Boost
Mode, 6.8V at 1A LED String
87
86
85
EFFICIENCY (%)
8
10 12 14 16 18 20 22 24 26
V
IN
(V)
80421 G14
Efficiency vs V
IN
, Buck-Boost
Mode, 10.1V at 1A LED String
75
70
65
60
55
84
83
82
81
80
75
4 6 8 10 12 14 16 18 20 22 24 26 28 30
V
IN
(V)
80421 G13
70
80
12 13 14 15 16 17 18 19 20 21 22 23 24
V
IN
(V)
80421 G15
Efficiency vs V
IN
, Buck-Boost
Mode, 13.4V at 1A LED String
90
89
MAXIMUM LED CURRENT (mA)
88
EFFICIENCY (%)
87
86
85
84
83
82
81
80
15
16
17
18
V
IN
(V)
19
20
80421 G16
Maximum LED Current
vs Input Voltage, Boost Operation
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
0
5
10
15
20
INPUT VOLTAGE (V)
25
30
80421 G17
80421fb
For more information
www.linear.com/LTM8042
5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
