Datasheet

18
LTC1149
LTC1149-3.3/LTC1149-5
TYPICAL APPLICATIO S
U
Figure 14. High Efficiency 48V Input 5V/2.5A Output Regulator
PGATE
V
IN

V
CC

PDRIVE
V
CC

C
T

I
TH

SENSE
–
CAP
SHDN2
RGND
NGATE
PGND
SGND
SHDN1
SENSE
+
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9

LTC1149-5
0.068µF
0.047µF
1N4148 1N4148
3300pF
1k
620pF3.3µF
1000pF
IRFZ34 MBR380
100µF
100V
L*
68µH
R
SENSE
**
0.04Ω
220µF
10V
OS-CON
1149 F14
V
OUT

5V/2.5A
*HURRICANE LAB HL-KI168M
**IRC LR2512-01-R040-G
MTD2955
SHUTDOWN
V
IN

48V
0.1µF
100Ω
100Ω
+
+
+
Figure 15. Logic Selectable 5V/2A or 3.3V/2A High Efficiency Regulator
PGATE
V
IN

V
CC

PDRIVE
V
CC

C
T

I
TH

SENSE
–
CAP
SHDN2
RGND
NGATE
PGND
SGND
V
FB

SENSE
+
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9

LTC1149
0.068µF
0.047µF
1N4148 1N4148
3300pF
1k
390pF1µF
1000pF
RFD14N05SM 1N5818
100µF
35V
V
IN

8V TO 20V
L*
50µH
R
SENSE
**
0.05Ω
220µF
10V × 2
AVX
1149 F15
V
OUT

3.3V/2A
OR 5V/2A
*COILTRONICS CTX50-2-MP
**IRC LR2010-01-R050-G
RFD15P05SM
SHUTDOWN
100pF
R1A
33k
1%
R2
56k
1%
VN2222LL
0V: V
OUT
= 3.3V
5V: V
OUT
= 5V
R1B
43k
1%
+
+
+