uc3842td STMicroelectronics, uc3842td Datasheet - Page 6

• Manufacturer Part Number: uc3842td
• Description: High Performance Current Mode Pwm Controller
• Manufacturer: STMicroelectronics

UC3842T - UC3843T - UC3844T - UC3845T
Figure 4: Oscillator Discharge Current vs. Tem-
Figure 6: Error Amp Open-Loop Gain and
Figure 8: Reference Voltage Change vs.
6/15
(dB)
I
-20
(mA)
dischg
80
60
40
20
0
60
50
40
30
20
10
8.5
8.0
7.5
7.0
0
10
0
-55
perature.
Phase vs. Frequency.
Source Current.
T
100
20
A
-25
=125˚C
40
1K
0
Gain
25
10K
60
T
A
50
=-40˚C
V
V
R
T
100K
V
80
A
i
O
L
V
V
=15V
=100K
=25˚C
i
=2V to 4V
=15V
i
OSC
=15V
75
100 I
=2V
1M
Phase
D95IN337
D95IN339
100 T
D95IN335
ref
f(Hz)
(mA)
A
(˚C)
120
150
180
30
60
90
Figure 5: Maximum Output Duty Cycle vs. Tim-
Figure 7: Current Sense Input Threshold vs. Er-
Figure 9: Reference Short Circuit Current vs.
D
(%)
max
90
80
70
60
50
40
(mA)
100
I
0.8
V
(V)
1.0
0.8
0.6
0.4
0.2
0.0
SC
90
80
70
60
50
th
-55
0
1
T
ing Resistor.
ror Amp Output Voltage.
Temperature.
V
A
I
-25
i
dischg
=125˚C
=15V
T
A
=25˚C
2
=7.5mA
0
T
A
2
=-40˚C
I
25
dischg
4
=8.8mA
50
3
V
R
i
L
=15V
75
0.1
6
V
C
T
i
A
T
=15V
100 T
=25˚C
=3.3nF
D95IN340
D95IN338
5
V
O
A
(V)
D95IN336
(˚C)
R
T
(K )