ST UC2842B, Руководство пользователя, Страница: 6 / 15

-55 -25 0 25 50 75 100 T
A
(˚C)
7.0
7.5
8.0
8.5
I
dischg
(mA)
D95IN335
V
i
=15V
V
OSC
=2V
Figure 4: Oscillator Discharge Current vs. Tem-
perature.
1 2 3 5
40
50
60
70
80
90
D
max
(%)
0.8 R
T
(K
Ω
)
D95IN336
V
i
=15V
C
T
=3.3nF
T
A
=25˚C
I
dischg
=7.5mA
I
dischg
=8.8mA
Figure 5: Maximum Output Duty Cycle vs. Tim-
ing Resistor.
10 100 1K 10K 100K 1M f(Hz)
-20
0
20
40
60
80
(dB)
180
150
120
90
60
30
φ
D95IN337
V
i
=15V
V
O
=2V to 4V
R
L
=100K
T
A
=25˚C
Gain
Phase
Figure 6: Error Amp Open-Loop Gain and
Phase vs. Frequency.
0 2 4 6 V
O
(V)
0.0
0.2
0.4
0.6
0.8
1.0
V
th
(V)
D95IN338
V
i
=15V
T
A
=-40˚C
T
A
=125˚C
T
A
=25˚C
Figure 7: Current Sense Input Threshold vs. Er-
ror Amp Output Voltage.
0 20 40 60 80 100 I
ref
(mA)
D95IN339
0
10
20
30
40
50
60
V
i
=15V
T
A
=-40˚C
T
A
=125˚C
T
A
=25˚C
Figure 8: Reference Voltage Change vs.
Source Current.
-55 -25 0 25 50 75 100 T
A
(˚C)
D95IN340
50
60
70
80
90
100
I
SC
(mA)
V
i
=15V
R
L
≤
0.1
Ω
Figure 9: Reference Short Circuit Current vs.
Temperature.
UC2842B/3B/4B/5B - UC3842B/3B/4B/5B
6/15