L4978
Figure 9. Switching Frequency vs. input
voltage.
Figure 10. Switching frequency vs. junction
temperature.
fsw
(KHz)
D97IN735
D97IN785
fsw
(KHz)
107.5
105.0
102.5
100.0
97.5
105
100
95
Tj=25°C
95.0
92.5
90.0
90
0
5 10 15 20 25 30 35 40 45 50 V (V)
CC
-50
0
50
100
Tj(°C)
Figure 11. Dropout voltage between pin 5
Figure 12. Efficiency vs output voltage.
and 4.
η
[%]
D98IN836
∆
V
98
96
94
92
90
88
86
84
82
80
(V)
fsw=100kHz
fsw=200kHz
0.7
Tj=125°C
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Tj=-25°C
Vcc=35V
Io=2A
0
5
10
15
20
25
30
Vo [V]
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 I (A)
O
Figure 14. Efficiencyvs.output current.
Figure 13. Efficiencyvs. output current.
η
η
[%]
[%]
95
90
85
80
75
70
65
60
95
90
85
80
75
70
65
60
Vcc=8V
Vcc=12V
Vcc=8V
Vcc=12V
Vcc=24V
Vcc=24V
Vcc=48V
Vo=3.36V
fsw=100kHz
fsw=100kHz
Vo=5.1V
Vcc=48V
0
0.2 0.4 0.6 0.8
1
1.2 1.4 1.6 1.8
2
2.2
0
0.2 0.4 0.6 0.8
1
1.2 1.4 1.6 1.8
2
2.2
Io [A]
Io [A]
7/12
STMICROELECTRONICS [ ST ]
