Datasheet

2
LT3431
sn3431 3431fs
(Note 1)
Input Voltage (V
IN
) ................................................. 60V
BOOST Pin Above SW ............................................ 35V
BOOST Pin Voltage ................................................. 68V
SYNC Voltage ........................................................... 7V
SHDN Voltage ........................................................... 6V
BIAS Pin Voltage .................................................... 30V
FB Pin Voltage/Current .................................. 3.5V/2mA
Operating Junction Temperature Range
LT3431EFE (Notes 8, 10) ................. –40°C to 125°C
LT3431IFE (Notes 8, 10) ................. –40°C to 125°C
Storage Temperature Range ................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
LT3431EFE
LT3431IFE
FE PART MARKING
PARAMETER CONDITIONS MIN TYP MAX UNITS
Reference Voltage (V
REF
) 5.5V ≤ V
IN
≤ 60V 1.204 1.219 1.234 V
V
OL
+ 0.2 ≤ V
C
≤ V
OH
– 0.2 ● 1.195 1.243 V
FB Input Bias Current ● –0.2 –1.5 µA
Error Amp Voltage Gain (Note 2) 200 475 V/V
Error Amp g
m
dl (V
C
) = ±10µA 1650 2200 3300 µMho
● 1000 4200 µMho
V
C
to Switch g
m
3.4 A/V
EA Source Current FB = 1V or V
SENSE
= 4.1V ● 125 275 450 µA
EA Sink Current FB = 1.4V or V
SENSE
= 5.7V ● 100 275 500 µA
V
C
Switching Threshold Duty Cycle = 0 0.8 V
V
C
High Clamp SHDN = 1V 2.1 V
Switch Current Limit V
C
Open, BOOST = V
IN
+ 5V, FB = 1V or V
SENSE
= 4.1V –40°C␣ ≤ Tj ≤ 25°C 3.0 5 6.5 A
(Note 9) Tj = 125°C 2.5 4 5.5 A
Switch On Resistance I
SW
= 2.5A, BOOST = V
IN
+ 5V (Note 7) 0.1 0.14 Ω
● 0.18 Ω
Maximum Switch Duty Cycle FB = 1V or V
SENSE
= 4.1V 88 92 %
● 80 %
Switch Frequency V
C
Set to Give DC = 50% 460 500 540 kHz
● 430 500 570 kHz
f
SW
Line Regulation 5.5V ≤ V
IN
≤ 60V ● 0.05 0.15 %/V
f
SW
Shifting Threshold Df = 10kHz 0.8 V
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
J
= 25°C.
V
IN
= 15V, V
C
= 1.5V, SHDN = 1V, BOOST open circuit, SW open circuit, unless otherwise noted.
T
JMAX
= 125°C, θ
JA
= 45°C/W, θ
JC
(PAD) = 10°C/W
EXPOSED PAD MUST BE SOLDERED
TO GROUND PLANE
ABSOLUTE AXI U RATI GS
WWWU
PACKAGE/ORDER I FOR ATIO
UU
W
ELECTRICAL CHARACTERISTICS
FE PACKAGE
16-LEAD PLASTIC TSSOP
1
2
3
4
5
6
7
8
TOP VIEW
16
15
14
13
12
11
10
9
GND
SW
V
IN
V
IN
SW
BOOST
NC
GND
GND
SHDN
SYNC
NC
FB
V
C
BIAS
GND
Consult LTC Marketing for parts specified with wider operating temperature ranges.
3431EFE
3431IFE