Datasheet

LT1431
9
1431fe
Typical applicaTions
Isolated 5V to ±15V Flyback Converter Fully Loaded Output Ripple vs Filtering
12V to 5V Buck Converter with Foldback Current Limit* Buck Converter Efficiency
2
COLL
REF
GND-F
COMP
GND-S
V
+
R
MID
R
TOP
1
1500pF
5 6
8
7
3
4
5k
V
IN
V
OUT
GNDLOGIC IN
V
IN
LT1089
HI-SIDE SWITCH
MBR735
100Ω
0.5W
PULSE ENGINEERING
#PE-51515
5V, 7A
3300µF
*CONTACT LTC FOR HIGH EFFICIENCY
SWITCHING REGULATORS
LT1431 TA09
LT1431
+
I
LOAD
(A)
0
EFFICIENCY (%)
60
70
80
3 5 8
LT1431 TA10
50
40
30
1 2
4
6 7
V
IN
= 9V
V
IN
= 12V
V
IN
= 15V
3
5 6
8
1
2
V
+
REF
GND-FGND-S
COLL
COMP
2.4k
0.1µF
20k
13.3k
2.7k
V
OUT
V
C
GND
V
IN
LT1172
OR
LT1072
1.5k
0.68µF
3k
0.47µF
50µF
4.5V
TO 5.5V
MUR105
4, 5
•
6, 7
•
2
10
•
9
MUR105
C*
15k
MUR105
C*
–15V, 70mA
15V, 70mA
COILTRONICS
CTX02-11934
MEASURED EFFICIENCY
LT1172 67.8% AT 2.2W
OUT
LT1072 68.6% AT 2.2W
OUT
LT1071 61.1% AT 4.4W
OUT
LT1431 TA11
1
LT1431
+
+
+
4N36
210µF
100µF 100µF
C* LT1172
30mV
P-P
LT1072
40mV
P-P
6mV
P-P
8mV
P-P
L*
*L BELL INDUSTRIES J.W. MILLER
DIVISION 9310-36 10µH, 450mA
LT1431 TA12
+
++