EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
LT3971-3.3, LT3971-5
TOP VIEW
BD
BOOST
SW
V
IN
EN
1
2
3
4
5
11
GND
MSE PACKAGE
10-LEAD PLASTIC MSOP
θ
JA
= 45°C,
θ
JC
= 10°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
MSE PACKAGE
16-LEAD PLASTIC MSOP
θ
JA
= 40°C
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
LT3971-3.3, LT3971-5
10 SYNC
9 PG
8 RT
7 SS
6 V
OUT
TOP VIEW
BD
BOOST
SW
V
IN
EN
1
2
3
4
5
11
GND
10
9
8
7
6
SYNC
PG
RT
SS
V
OUT
DD PACKAGE
10-LEAD (3mm
×
3mm) PLASTIC DFN
θ
JA
= 45°C,
θ
JC
= 10°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
MSE PACKAGE
10-LEAD PLASTIC MSOP
θ
JA
= 45°C,
θ
JC
= 10°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT3971EDD#PBF
LT3971IDD#PBF
LT3971EMSE#PBF
LT3971IMSE#PBF
LT3971EMSE16#PBF
LT3971IMSE16#PBF
LT3971EDD-3.3#PBF
LT3971IDD-3.3#PBF
LT3971EMSE-3.3#PBF
LT3971IMSE-3.3#PBF
TAPE AND REEL
LT3971EDD#TRPBF
LT3971IDD#TRPBF
LT3971EMSE#TRPBF
LT3971IMSE#TRPBF
LT3971EMSE16#TRPBF
LT3971IMSE16#TRPBF
LT3971EDD-3.3#TRPBF
LT3971IDD-3.3#TRPBF
LT3971EMSE-3.3#TRPBF
LT3971IMSE-3.3#TRPBF
PART MARKING*
LFJF
LFJF
LTFJG
LTFJG
3971
3971
LFRM
LFRM
LTFRN
LTFRN
PACKAGE DESCRIPTION
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead Plastic MSOP
10-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead Plastic MSOP
10-Lead Plastic MSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
3971fd
2
LT3971/LT3971-3.3/LT3971-5
ORDER INFORMATION
LEAD FREE FINISH
LT3971EDD-5#PBF
LT3971IDD-5#PBF
LT3971EMSE-5#PBF
LT3971IMSE-5#PBF
TAPE AND REEL
LT3971EDD-5#TRPBF
LT3971IDD-5#TRPBF
LT3971EMSE-5#TRPBF
LT3971IMSE-5#TRPBF
PART MARKING*
LFRP
LFRP
LTFRQ
LTFRQ
PACKAGE DESCRIPTION
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead Plastic MSOP
10-Lead Plastic MSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–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.
Consult LTC Marketing for information on non-standard lead based finish parts.
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/
ELECTRICAL CHARACTERISTICS
PARAMETER
Minimum Input Voltage
Quiescent Current from V
IN
LT3971 FB Pin Current
Internal Feedback Resistor Divider (LT3971-X)
Feedback Voltage
LT3971-3.3 Output Voltage
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
EN
= 12V, V
BD
= 3.3V unless otherwise noted. (Note 2)
CONDITIONS
(Note 4)
V
EN
Low
V
EN
High, V
SYNC
Low
V
EN
High, V
SYNC
Low
V
FB
= 1.19V
MIN
l
TYP
4
0.7
1.7
0.1
10
1.19
1.19
3.3
3.3
5
5
0.0002
2
1
200
80
110
2.4
330
0.02
770
0.02
1.4
20
1.01
30
0.2
100
20
9
1.3
l
l
MAX
4.3
1.2
2.7
4.5
12
1.205
1.215
3.35
3.376
5.07
5.11
0.01
2.4
1.2
240
150
3
1
1
1.8
28
1.07
20
140
12.5
l
l
LT3971-5 Output Voltage
l
1.175
1.165
3.25
3.224
4.93
4.89
1.6
0.8
160
FB Voltage Line Regulation
Switching Frequency
Minimum Switch On Time
Minimum Switch Off Time
Switch Current Limit
Switch V
CESAT
Switch Leakage Current
Boost Schottky Forward Voltage
Boost Schottky Reverse Leakage
Minimum Boost Voltage (Note 3)
BOOST Pin Current
EN Voltage Threshold
EN Voltage Hysteresis
EN Pin Current
LT3971 PG Threshold Offset from V
FB
LT3971 PG Hysteresis
LT3971-X PG Threshold Offset from V
OUT
LT3971-X PG Hysteresis
4.3V < V
IN
< 38V (Note 4)
R
T
= 11k
R
T
= 35.7k
R
T
= 255k
1.8
I
SW
= 1A
I
SH
= 100mA
V
REVERSE
= 12V
V
IN
= 5V
I
SW
= 1A, V
BOOST
= 15V
EN Rising
l
l
0.95
V
FB
Rising
V
OUT
Rising
60
5.5
UNITS
V
μA
μA
μA
nA
MΩ
V
V
V
V
V
V
%/V
MHz
MHz
kHz
ns
ns
A
mV
μA
mV
μA
V
mA
V
mV
nA
mV
mV
%
%
3971fd
3
LT3971/LT3971-3.3/LT3971-5
ELECTRICAL CHARACTERISTICS
PG Leakage
PG Sink Current
SYNC Threshold
SYNC Pin Current
SS Source Current
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
EN
= 12V, V
BD
= 3.3V unless otherwise noted. (Note 2)
V
PG
= 3V
V
PG
= 0.4V
l
300
0.6
0.6
V
SS
= 1V
0.02
570
0.8
0.1
1
1
1.0
1.6
µA
μA
V
nA
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.
Note 2:
The LT3971E is guaranteed to meet performance specifications
from 0°C to 125°C junction temperature. Specifications over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization, and correlation with statistical process controls. The
LT3971I is guaranteed over the full –40°C to 125°C operating junction
temperature range. High junction temperatures degrade operating
lifetimes. Operating lifetime is derated at junction temperatures greater
than 125°C.
Note 3:
This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the switch.
Note 4:
This is the minimum input voltage for operation with accurate FB
regulation. Minimum input voltage for output regulation depends on the