L4978
Figure 15. Efficiencyvs. output current.
Figure 16. Efficiencyvs.output current.
D97IN740
D97IN741
η
(%)
η
(%)
V
=8V
CC
V
=8V
CC
90
85
80
75
70
65
60
90
85
80
75
70
65
60
55
V
=12V
CC
V
CC
=24V
V
=12V
CC
V
=24V
CC
V
CC
=48V
V
CC
=48V
fsw=200KHz
V =5.1V
fsw=200KHz
V =3.36V
O
O
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 I (A)
O
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 I (A)
O
Figure 17. Efficiencyvs. Vcc.
Figure 18. Powerdissipationvs. Vcc.
n [%]
90
Pdiss[mW]
1000
Vo=5.1V
fsw=100kHz
Vo=5.1Vfsw=100kHz
800
Io=2A
85
80
75
70
Vo=5.1V fsw=200kHz
600
Vo=3.36V fsw=100kHz
Io=1A
Io=1.5A
Vo=3.36Vfsw=200kHz
400
Io=0.5A
200
Io=2A
0
0
10
20
30
40
50
60
0
10
20
30
40
50
60
Vcc [V]
Vcc [V]
Figure 19. DevicePowerdissipationvs.Vo
Figure 20. Pulseby pulse limitingcurrentvs.
junction temperature.
Pdiss [mW]
1400
Ilim
D97IN747
Vcc=35V
(A)
fsw=100kHz
1200
fsw=100KHz
Io=2A
2.9
2.8
2.7
2.6
2.5
2.4
2.3
V
CC
=35V
1000
Io=1.5A
800
600
Io=1A
400
Io=0.5A
200
0
0
10
20
Vo [V]
30
-50 -25
0
25 50 75 100 125 Tj(°C)
8/12
STMICROELECTRONICS [ ST ]
