Datasheet

18
LT1777
TYPICAL APPLICATIONS
U
Figure 9. Efficiency and LT1777 Internal Dissipation for the Basic 5V Output Application
Internal Dissipation
I
OUT
(mA)
0
0.6
0.4
0.2
1.4
1.2
1.0
0.8
1777 F09b
INTERNAL DISSIPATION (W)
10
1000
100
1µH
0µH
L
SENSE
=
2.2µH
V
IN
= 12V
V
OUT
= 5V
T
A
= 25°C
I
OUT
(mA)
0
0.6
0.4
0.2
1.4
1.2
1.0
0.8
1777 F09d
INTERNAL DISSIPATION (W)
10
1000
100
1µH
0µH
L
SENSE
=
2.2µH
V
IN
= 24V
V
OUT
= 5V
T
A
= 25°C
I
OUT
(mA)
0
0.6
0.4
0.2
1.4
1.2
1.0
0.8
1777 F09f
INTERNAL DISSIPATION (W)
10
1000
100
1µH
0µH
L
SENSE
=
2.2µH
V
IN
= 36V
V
OUT
= 5V
T
A
= 25°C
V
IN
= 12V
V
IN
= 24V
V
IN
= 36V
Efficiency
I
LOAD
(mA)
1
90
EFFICIENCY (%)
20
30
40
10 100 1000
1777 F09a
80
70
60
50
V
IN
= 12V
V
OUT
= 5V
T
A
= 25°C
L
SENSE
=
0µH
1µH
2.2µH
I
LOAD
(mA)
1
90
EFFICIENCY (%)
20
30
40
10 100 1000
1777 F09c
80
70
60
50
V
IN
= 24V
V
OUT
= 5V
T
A
= 25°C
L
SENSE
=
0µH
1µH
2.2µH
I
LOAD
(mA)
1
90
EFFICIENCY (%)
20
30
40
10 100 1000
1777 F09e
80
70
60
50
V
IN
= 36V
V
OUT
= 5V
T
A
= 25°C
L
SENSE
=
0µH
1µH
2.2µH