Datasheet

LT3958
25
3958f
TYPICAL APPLICATIONS
10V to 60V Input, 12V Output SEPIC Converter
Effi ciency vs Output Current
Load Step Waveforms
OUTPUT CURRENT (mA)
0
50
EFFICIENCY (%)
65
60
55
70
75
80
85
90
200 400 600
800
3958 TA04b
1000
V
IN
= 24V
500µs/DIV
V
OUT
0.5V/DIV
(AC)
I
OUT
0.5A/DIV
0.8A
0.2A
3958 TA04c
V
IN
= 24V
Start-Up Waveforms
Frequency Foldback Waveforms
When Output Short-Circuit
5ms/DIV
V
OUT
5V/DIV
I
L1A
+ I
L1B
2A/DIV
3958 TA04d
V
IN
= 24V
50µs/DIV
V
OUT
10V/DIV
V
SW
20V/DIV
I
L1A
+ I
L1B
2A/DIV
3958 TA04e
V
IN
= 24V
SENSE2
SENSE1
LT3958
L1A
L1B
V
IN
SW
GND
FBX
RT SS
INTV
CC
EN/UVLO
SYNC
SGND
66.5k
VC
3958 TA04a
D1
392k
41.2k
300kHz
C
VCC
4.7µF
10V
X5R
0.47µF
10k
10nF
105k
15.8k
C
DC
2.2µF, 100V
X7R, s2
V
OUT
12V
1A
V
IN
10V TO 60V
C
IN
2.2µF
100V
X5R
C
OUT
22µF
16V
X5R
s2
•
•
C
IN
, C
DC
: MURATA GRM32ER72A225KA35L
C
OUT
: MURATA GRM32ER61C226KE20
D1: VISHAY SILICONIX 10MQ100N
L1A, L1B: COILTRONICS DRQ125-220