FB, RT, SYNC, SS Voltage ...........................................6V
PG Voltage ................................................................30V
OUT Voltage ..............................................................16V
Operating Junction Temperature Range (Note 2)
LT3975E............................................. –40°C to 125°C
LT3975I.............................................. –40°C to 125°C
LT3975H ............................................ –40°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................... 300°C
17
GND
MSE PACKAGE
16-LEAD PLASTIC MSOP
θ
JA
= 40°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT3975EMSE#PBF
LT3975IMSE#PBF
LT3975HMSE#PBF
TAPE AND REEL
LT3975EMSE#TRPBF
LT3975IMSE#TRPBF
LT3975HMSE#TRPBF
PART MARKING*
3975
3975
3975
PACKAGE DESCRIPTION
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°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.
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
Dropout Comparator Threshold
Dropout Comparator Threshold Hysteresis
Quiescent Current from V
IN
FB Pin Current
Feedback Voltage
FB Voltage Line Regulation
Switching Frequency
Minimum Switch On-Time
Minimum Switch Off-Time (Note 4)
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 2)
CONDITIONS
(Note 3)
(V
IN
– OUT) Falling
V
EN
Low
V
EN
High, V
SYNC
Low
V
EN
High, V
SYNC
Low
V
FB
= 1.5V
MIN
l
430
TYP
4
500
25
0.7
1.6
0.1
1.197
1.197
0.0003
2.25
1
200
105
150
MAX
4.3
570
1.3
2.7
30
12
1.212
1.222
0.01
2.7
1.2
240
200
l
l
l
1.183
1.173
1.8
0.8
160
4.3V < V
IN
< 40V (Note 3)
R
T
= 11.8k
R
T
= 41.2k
R
T
= 294k
UNITS
V
mV
mV
µA
µA
µA
nA
V
V
%/V
MHz
MHz
kHz
ns
ns
3975f
2
LT3975
ELECTRICAL CHARACTERISTICS
PARAMETER
Switch Current Limit
Foldback Switch Current Limit
Switch V
CESAT
Switch Leakage Current
Boost Schottky Forward Voltage
Boost Schottky Reverse Leakage
Minimum Boost Voltage (Note 5)
BOOST Pin Current
EN Voltage Threshold
EN Voltage Hysteresis
EN Pin Current
PG Threshold Offset from V
FB
PG Hysteresis as % of Output Voltage
PG Leakage
PG Sink Current
SYNC Low Threshold
SYNC High 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. (Note 2)
CONDITIONS
V
FB
= 1V
V
FB
= 0V
I
SW
= 1A
I
SH
= 100mA
V
REVERSE
= 12V
l
MIN
4
I
SW
= 1A, V
BOOST
– V
SW
= 3V
EN Falling, V
IN
≥ 4.3V
l
0.92
V
FB
Falling
V
PG
= 3V
V
PG
= 0.4V
5
l
125
0.6
V
SYNC
= 6V
V
SS
= 0.5V
0.9
TYP
5.4
3.3
80
0.02
730
0.02
1.3
20
1.02
60
0.2
8.4
1.7
0.02
480
1.0
1.18
0.1
1.8
MAX
6.8
1
2
1.8
32
1.12
20
13
1
1.5
2.6
UNITS
A
A
mV
μA
mV
μA
V
mA
V
mV
nA
%
%
µA
μA
V
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 LT3975E 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
LT3975I is guaranteed over the full –40°C to 125°C operating junction
temperature range. The LT3975H is guaranteed over the full –40°C to
150°C operating junction temperature range. High junction temperatures
degrade operating lifetimes. Operating lifetime is derated at junction
temperatures greater than 125°C. The junction temperature (T
J
, in °C) is
calculated from the ambient temperature (T
A
, in °C) and power dissipation
(P
D
, in Watts) according to the formula:
T
J
= T
A
+ (P
D
•
θ
JA
)
where
θ
JA
(in °C/W) is the package thermal impedance.
Note 3:
Minimum input voltage depends on application circuit.
Note 4:
The LT3975 contains circuitry that extends the maximum duty
cycle if there is sufficient voltage across the boost capacitor. See the
Application Information section for more details.
Note 5:
This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the switch.
Note 6:
This IC 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 maximum operating junction temperature may impair device
