L4978
Figure 4. Quiescent current vs. junction
temperature
Figure 3. Quiescent drain current vs. input
voltage.
D97IN731
Iq
(mA)
D97IN724
Iq
(mA)
200KHz
R
=22K
1
200KHz
R1=22K
C2=1.2nF
C =1.2nF
5
4
3
2
1
2
5
4
3
2
1
100KHz
=20K
C =2.7nF
2
R
1
100KHz
R1=20K
C2=2.7nF
0Hz
0Hz
VCC=35V
0% DC
Tamb=25°
C
0% DC
-50 -30 -10 10 30 50 70 90 110 Tj(°C)
Vcc(V)
0
5 10 15 20 25 30 35 40 45 50
Figure 6. Line Regulation
Figure 5. Stand by drain current vs. input
voltage
V
O
(V)
D97IN733
Ibias
D97IN732
(µA)
3.377
Vss=GND
150
140
130
120
110
100
90
Tj=125°C
Tj=25°C
3.376
3.375
3.374
3.373
3.372
3.371
3.370
Tj=25°C
Tj=125°C
80
70
60
0
5 10 15 20 25 30 35 40 45 50 V (V)
CC
0
5 10 15 20 25 30 35 40 45 50 V (V)
CC
Figure 8. Switching frquency vs. R1 and C2
Figure 7. Load regulation
fsw
(KHz)
D97IN784
V
O
(V)
D98IN835
V
CC=35V
3.378
Tamb=25°C
500
3.376
3.374
3.372
200
100
50
Tj=25°C
3.370
3.368
3.366
3.364
3.362
3.360
Tj=125°C
20
10
5
0
20
40
60
80 R1(KΩ)
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 I (A)
O
6/12
STMICROELECTRONICS [ ST ]
