UC3844B STMicroelectronics, UC3844B Datasheet - Page 12

• Manufacturer Part Number: UC3844B
• Description: Current Mode PWM
• Manufacturer: STMicroelectronics

Figure 24: Soft-Start Circuit
UC2842B/3B/4B/5B - UC3842B/3B/4B/5B
Figure 25: Soft-Start and Error Amplifier Output Duty Cycle Clamp.
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C
R2
R1
BC109
C
8
4
2
1
1M
+
-
EA
V
8
4
2
1
CLAMP
+
R
R
=
1mA
·
+
-
R
1
EA
R
+ R
1
2
BIAS
OSC
2R
+
where 0 <V
R
R
R
1mA
5
V
Clamp
BIAS
OSC
CLAMP
1V
2R
<1V
R
+
+
-
-
5V
5
I
pk(max)
ref
Comp/Latch
=
5V
1V
S
R
ref
Q
V
CLAMP
R
S
+
+
-
-
+
D95IN354
-
7
S
R
Q
D95IN355
7
6
5
V
CC
R
S
V
in
Q1