L4978
Figure 6. Quiescent drain current vs. input
voltage.
Iq
(mA)
200KHz
R
1
=22K
C
2
=1.2nF
100KHz
R
1
=20K
C
2
=2.7nF
D97IN724
Figure 9. Line Regulation
.
V
O
(V)
3.377
Tj=125˚C
D97IN733
5
3.376
3.375
Tj=25˚C
4
3.374
3
0Hz
3.373
3.372
2
Tamb=25˚C
0% DC
3.371
3.370
1
0
5 10 15 20 25 30 35 40 45 50
Vcc(V)
0
5 10 15 20 25 30 35 40 45 50 V
CC
(V)
Figure 7. Quiescent current vs. junction
temperature
Iq
(mA)
5
D97IN731
Figure 10. Load regulation
.
V
O
(V)
3.378
3.376
3.374
3.372
3.370
3.368
Tj=125˚C
Tj=25˚C
D98IN835
V
CC
=35V
200KHz
R
1
=22K
C
2
=1.2nF
100KHz
R
1
=20K
C
2
=2.7nF
0Hz
4
3
V
CC
=35V
0% DC
3.366
3.364
3.362
2
1
-50 -30 -10 10 30 50 70 90 110
Tj(˚C)
3.360
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 I
O
(A)
Figure 8. Stand by drain current vs. input
voltage.
Ibias
(µA)
150
140
130
120
110
100
90
80
70
60
0
5 10 15 20 25 30 35 40 45 50 V
CC
(V)
Tj=125˚C
Vss=GND
Tj=25˚C
D97IN732
Figure 11. Switching frquency vs. R1 and C2
.
fsw
(KHz)
500
200
100
50
20
5.6n
F
D97IN784
Tamb=25˚C
0.8
2
nF
1.2
nF
2.2
nF
3.3n
F
4.7n
F
10
5
0
20
40
60
80
R1(KΩ)
6/13
STMICROELECTRONICS [ STMICROELECTRONICS ]
