LT3791E/LT3791I ............................... –40°C to 125°C
LT3791H ............................................ –40°C to 150°C
LT3791MP ......................................... –55°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................... 300°C
IVINP 10
IVINN 11
V
IN
12
INTV
CC
13
TG1 14
BST1 15
SW1 16
PGND 17
BG1 18
BG2 19
FE PACKAGE
38-LEAD PLASTIC TSSOP
T
JMAX
= 150°C,
θ
JA
= 28°C/W
EXPOSED PAD (PIN 39) IS SGND, MUST BE SOLDERED TO PCB
orDer inForMaTion
LEAD FREE FINISH
LT3791EFE#PBF
LT3791IFE#PBF
LT3791HFE#PBF
LT3791MPFE#PBF
TAPE AND REEL
LT3791EFE#TRPBF
LT3791IFE#TRPBF
LT3791HFE#TRPBF
LT3791MPFE#TRPBF
http://www.linear.com/product/LT3791#orderinfo
PART MARKING*
LT3791FE
LT3791FE
LT3791FE
LT3791FE
PACKAGE DESCRIPTION
38-Lead Plastic TSSOP
38-Lead Plastic TSSOP
38-Lead Plastic TSSOP
38-Lead Plastic TSSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–55°C to 150°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:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
elecTrical characTerisTics
PARAMETER
Input
V
IN
Operating Voltage
V
IN
Shutdown I
Q
V
IN
Operating I
Q
(Not Switching)
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 12V, V
EN/UVLO
= 12V unless otherwise noted.
CONDITIONS
MIN
4.7
V
EN/UVLO
= 0V
FB = 1.3V, R
T
= 59.0k
0.1
3.0
TYP
MAX
60
1
4
UNITS
V
µA
mA
3791fc
2
For more information
www.linear.com/LT3791
LT3791
elecTrical characTerisTics
PARAMETER
Logic Inputs
EN/UVLO Falling Threshold
EN/UVLO Rising Hysteresis
EN/UVLO Input Low Voltage
EN/UVLO Pin Bias Current Low
EN/UVLO Pin Bias Current High
CTRL Input Bias Current
CTRL Latch-Off Threshold
OVLO Rising Shutdown Voltage
OVLO Falling Hysteresis
Regulation
V
REF
Voltage
V
REF
Line Regulation
V
(ISP-ISN)
Threshold
4.7V < V
IN
< 60V
V
CTRL
= 2V
l
l
l
l
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 12V, V
EN/UVLO
= 12V unless otherwise noted.
CONDITIONS
MIN
1.16
TYP
1.2
15
I
VIN
Drops Below 1µA
V
EN/UVLO
= 1V
V
EN/UVLO
= 1.6V
V
CTRL
= 1V
2.85
2
3
10
20
175
3
75
1.96
97.5
94
87
84
47.5
46
6.5
5
2.00
0.002
100
100
90
90
50
50
10
10
110
20
0
890
V
(ISP-ISN)
= 100mV
3V ≤ V
IVINP
≤ 60V
l
l
MAX
1.24
0.3
4
100
50
3.15
UNITS
V
mV
V
µA
nA
nA
mV
V
mV
2.04
0.04
102.5
106
93
96
52.5
54
13.5
15
V
%/V
mV
mV
mV
mV
mV
mV
mV
mV
µA
µA
V
CTRL
= 1100mV
l
V
CTRL
= 700mV
l
V
CTRL
= 300mV
l
ISP Bias Current
ISN Bias Current
LED Current Sense Common Mode Range
LED Current Sense Amplifier g
m
ISMON Monitor Voltage
Input Current Sense Threshold V
(IVINP-IVINN)
IVINP Bias Current
IVINN Bias Current
Input Current Sense Common Mode Range
Input Current Sense Amplifier g
m
IVINMON Monitor Voltage
FB Regulation Voltage
l
60
1
50
90
20
1.04
54
V
µS
V
mV
µA
µA
0.96
46.5
3
2.12
V
(IVINP-IVINN)
= 50mV
l
60
1
1.2
1.2
0.002
565
100
1.04
1.206
1.220
0.025
200
20
51
–47.5
14
1.4
60
–39
V
mS
V
V
V
%/V
µS
nA
nA
mV
mV
µA
µA
V
0.96
1.194
1.176
FB Line Regulation
FB Amplifier g
m
FB Pin Input Bias Current
V
C
Standby Input Bias Current
V
SENSE(MAX)
(V
SNSP-SNSN
)
Fault
SS Pull-Up Current
SS Discharge Current
FB Overvoltage Rising Threshold
Open LED Rising Threshold (V
FB
)
4.7V < V
IN
< 60V
FB in Regulation
PWM = 0V
Boost
Buck
V
SS
= 0V
1.22
V
(ISP-ISN)
= 0V
l
l
l
–20
42
–56
1.25
1.15
1.173
1.127
V
3791fc
For more information
www.linear.com/LT3791
3
LT3791
elecTrical characTerisTics
PARAMETER
Open LED Falling Threshold (V
FB
)
Open LED Falling Threshold (V
(ISP-ISN)
)
Short LED Falling Threshold (V
FB
)
OPENLED
Pin Output Impedance
SHORTLED
Pin Output Impedance
SS Latch-Off Threshold
SS Reset Threshold
Oscillator
Switching Frequency
R
T
= 147k
R
T
= 59.0k
R
T
= 29.1k
190
380
665
200
90
0.3
4.8
I
INTVCC
= –10mA, V
IN
= 5V
3.1
V
INTVCC
= 4V
0.3
90
10
5
V
BST
– V
SW
= 5V
V
INTVCC
= 5V
C
L
= 3300pF
C
L
= 3300pF
R
T
= 59.0k
20
10
5
240
3.5
67
1.5
1.5
5.2
350
3.9
200
400
700
210
420
735
700
kHz
kHz
kHz
kHz
kΩ
V
V
mV
V
mA
V
kΩ
Ω
Ω
V
FB
= 1.2V
The
l
denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 12V, V
EN/UVLO
= 12V unless otherwise noted.
CONDITIONS
l
MIN
1.078
5
380
TYP
1.1
10
400
1.1
1.1
1.75
0.2
MAX
1.122
15
450
2.0
2.0
UNITS
V
mV
mV
kΩ
kΩ
V
V
SYNC Frequency
SYNC Pin Resistance to GND
SYNC Threshold Voltage
Internal V
CC
Regulator
INTV
CC
Regulation Voltage
Dropout (V
IN
– INTV
CC
)
INTV
CC
Undervoltage Lockout
INTV
CC
Current Limit
PWM
PWM Threshold Voltage
PWM Pin Resistance to GND
PWMOUT Pull-Up Resistance
PWMOUT Pull-Down Resistance
NMOS Drivers
TG1, TG2 Gate Driver On-Resistance
Gate Pull-Up
Gate Pull-Down
BG1, BG2 Gate Driver On-Resistance
Gate Pull-Up
Gate Pull-Down
TG Off to BG On Delay
BG Off to TG On Delay
TG1, TG2, t
OFF(MIN)
2.6
1.7
3
1.2
60
60
240
320
Ω
Ω
Ω
Ω
ns
ns
ns
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:
The LT3791E is guaranteed to meet performance from 0°C
to 125°C junction temperature. Specification over the -40°C to
125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls.
The LT3791I is guaranteed to meet performance specifications over the
–40°C to 125°C operating junction temperature range. The LT3791H is
guaranteed to meet performance specifications over the –40°C to 150°C
operating junction temperature range. The LT3791MP is guaranteed to
meet performance specifications over the –55°C to 150°C operating
junction temperature range. High junction temperatures degrade operating
lifetimes. Operating lifetime is derated for junction temperatures greater
than 125°C.
Note 3:
The LT3791 includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed the maximum operating junction temperature
when overtemperature protection is active. Continuous operation above
the specified absolute maximum operating junction temperature may
