Datasheet

LT4363
18
4363fa
TYPICAL APPLICATIONS
Overvoltage Regulator with Output Keep Alive During Shutdown
C
TMR
0.1µF
R
SNS
10mΩ
Q1
IRLR2908
V
IN
V
OUT
12V, 4A
REGULATED
AT 16V
4363 TA02
LT4363DE-2
GND TMR
9 12
OUT
2
SNS
3
FB
1
D1*
SMAJ58A
R2
24.9k
R1
287k
R7
1k
GATE
4
V
CC
5
R3
10Ω
R9
1k, 1W
*DIODES INC.
**SANYO 25CE22GA
SHDN
6
UV
8
OV
7
FLT
ENOUT
10
11
C
L
**
22µF
R5
30.1k
R6
10k
R4
147k
D2
1N4746A
18V
1W
UV = 6V
OV = 24V
C1
47nF
APPLICATIONS INFORMATION
The power dissipation in Q1 is:
P =
14V • 25mV
10mΩ
= 35W
During an output overload or soft short, the voltage at the
OUT pin could stay at 2V or higher. The total overcurrent
fault time when V
OUT
= 2V is:
t
OC
=
47nF • 0.875V
40µA
= 1.028ms
The power dissipation in Q1 is:
P =
14V – 2V
( )
• 50mV
10mΩ
= 60W
These conditions are well within the Safe Operating Area
of the FDB33N25.