Datasheet

LT3971/LT3971-3.3/LT3971-5
3
3971fd
ELECTRICAL CHARACTERISTICS
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)
ORDER INFORMATION
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage (Note 4)
l
4 4.3 V
Quiescent Current from V
IN
V
EN
Low
V
EN
High, V
SYNC
Low
V
EN
High, V
SYNC
Low
l
0.7
1.7
1.2
2.7
4.5
μA
μA
μA
LT3971 FB Pin Current V
FB
= 1.19V
l
0.1 12 nA
Internal Feedback Resistor Divider (LT3971-X) 10 MΩ
Feedback Voltage
l
1.175
1.165
1.19
1.19
1.205
1.215
V
V
LT3971-3.3 Output Voltage
l
3.25
3.224
3.3
3.3
3.35
3.376
V
V
LT3971-5 Output Voltage
l
4.93
4.89
5
5
5.07
5.11
V
V
FB Voltage Line Regulation 4.3V < V
IN
< 38V (Note 4) 0.0002 0.01 %/V
Switching Frequency R
T
= 11k
R
T
= 35.7k
R
T
= 255k
1.6
0.8
160
2
1
200
2.4
1.2
240
MHz
MHz
kHz
Minimum Switch On Time 80 ns
Minimum Switch Off Time 110 150 ns
Switch Current Limit 1.8 2.4 3 A
Switch V
CESAT
I
SW
= 1A 330 mV
Switch Leakage Current 0.02 1 μA
Boost Schottky Forward Voltage I
SH
= 100mA 770 mV
Boost Schottky Reverse Leakage V
REVERSE
= 12V 0.02 1 μA
Minimum Boost Voltage (Note 3) V
IN
= 5V
l
1.4 1.8 V
BOOST Pin Current I
SW
= 1A, V
BOOST
= 15V 20 28 mA
EN Voltage Threshold EN Rising
l
0.95 1.01 1.07 V
EN Voltage Hysteresis 30 mV
EN Pin Current 0.2 20 nA
LT3971 PG Threshold Offset from V
FB
V
FB
Rising 60 100 140 mV
LT3971 PG Hysteresis 20 mV
LT3971-X PG Threshold Offset from V
OUT
V
OUT
Rising 5.5 9 12.5 %
LT3971-X PG Hysteresis 1.3 %
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3971EDD-5#PBF LT3971EDD-5#TRPBF LFRP
10-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT3971IDD-5#PBF LT3971IDD-5#TRPBF LFRP
10-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT3971EMSE-5#PBF LT3971EMSE-5#TRPBF LTFRQ 10-Lead Plastic MSOP –40°C to 125°C
LT3971IMSE-5#PBF LT3971IMSE-5#TRPBF LTFRQ 10-Lead Plastic MSOP –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/