Datasheet

LT3758/LT3758A
32
3758afd
typicAl ApplicAtions
10V to 40V Input, –12V Output Inverting Converter
SENSE
LT3758A
V
IN
V
IN
10V TO 40V
C
IN2
4.7µF
50V
X7R
×2
C
DC
2.2µF
100V
X7R, ×2
0.015Ω
M1
41.2k
300kHz
GATE
FBX
GND
INTV
CC
SHDN/UVLO
SYNC
RT
SS
•
0.47µF
10k
L1A
3758 TA07a
C
VCC
4.7µF
10V
X5R
V
C
C
IN1
4.7µF
50V
×2
C
OUT2
47µF
20V
×2
+
+
R1
200k
R2
32.4k
6.8nF
•
L1B
D1
V
OUT
–12V
2A
105k
7.5k
C
OUT1
22µF
16V
X5R
×4
C
IN1
: KEMET T495X475K050AS
C
IN2
, C
DC
: MURATA GRM32ER71H475KA88L
C
OUT1
: MURATA GRM32ER61C226KE20
C
OUT2
: KEMET T495X476K020AS
D1: VISHAY SILICONIX 30BQ060
L1A, L1B: COILTRONICS DRQ127-150
M1: VISHAY SILICONIX SI7850DP
Efficiency vs Output Current
OUTPUT CURRENT (A)
0.001
10
EFFICIENCY (%)
30
20
40
50
60
70
80
90
100
0.01
0.1 1
3758 TA07b
10
V
IN
= 40V
V
IN
= 24V
V
IN
= 10V
Load Step Waveforms
500µs/DIV
V
OUT
1V/DIV
AC-COUPLED
I
OUT
1A/DIV
0A
1A
3758 TA07c
V
IN
= 24V
Start-Up Waveforms
5ms/DIV
V
OUT
5V/DIV
IL
1A +
IL
1B
2A/DIV
3758 TA07d
V
IN
= 24V
50µs/DIV
V
SW
20V/DIV
V
OUT
10V/DIV
IL
1A +
IL
1B
5A/DIV
3758 TA07e
V
IN
= 24V
Frequency Foldback Waveforms
When Output Short-Circuit