UC3842T STMICROELECTRONICS [STMicroelectronics], UC3842T Datasheet - Page 11

• Manufacturer Part Number: UC3842T
• Description: HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Figure 22: External Clock Synchronization.
Figure 23: External Duty Cycle Clamp and Multi Unit Synchronization.
f =
R
R
C
(R
A
B
A
V
1.44
+ 2R
REF
SYNC INPUT
The diode clamp is required if the Sync amplitude is large enough to cause
the bottom side of C
EXTERNAL
B
)C
6
5
2
5K
5K
5K
D
max
8
1
=
0.01 F
+
+
-
-
R
A
R
+ 2R
B
T
NE555
B
to go more than 300mV below ground
R
S
Q
4
47
R
C
T
T
V
REF
8
4
2
1
3
7
+
-
U3842T - UC3843T - UC3844T - UC3845T
EA
+
8
4
2
1
R
R
+
-
BIAS
OSC
EA
TO ADDITIONAL
2R
UC384XT
R
+
R
R
5
BIAS
OSC
D95IN352
D99IN1060
2R
R
5
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