UC3842BN ON Semiconductor, UC3842BN Datasheet - Page 14

• Manufacturer Part Number: UC3842BN
• Description: IC CTRLR CURRENT MODE HP 8DIP
• Manufacturer: ON Semiconductor

Specifications of UC3842BN

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 275kHz
• Duty Cycle: 96%
• Voltage - Supply: 11.5 V ~ 25 V
• Buck: No
• Boost: Yes
• Flyback: Yes
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• Frequency-max: 275kHz
• Duty Cycle (max): 96 %
• Output Voltage: 4.9 V to 5.1 V
• Output Current: 1000 mA
• Mounting Style: Through Hole
• Switching Frequency: 500 KHz
• Operating Supply Voltage: 30 V
• Maximum Operating Temperature: + 70 C
• Fall Time: 50 ns
• Minimum Operating Temperature: 0 C
• Rise Time: 50 ns
• Synchronous Pin: No
• Topology: Boost, Flyback, Forward
• Case: DIP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: UC3842BNOS

From V
O
R
R
i
d
MPS3904
R
Slope
C
f
C
T
R
8(14)
The buffered oscillator ramp can be resistively summed with either the voltage
feedback or current sense inputs to provide slope compensation.
4(7)
2(3)
1(1)
T
R
Error Amp compensation circuit for stabilizing any current mode topology except for boost and flyback
converters operating with continuous inductor current.
f
C
Figure 32. Error Amplifier Compensation
From V
R
p
Error Amp compensation circuit for stabilizing current mode boost and flyback
topologies operating with continuous inductor current.
p
O
- 3.0m
EA
Figure 33. Slope Compensation
R
R
R
From V
R
i
R
R
d
d
i
R
+
f
≥ 8.8 k
Osc
O
1.0mA
Bias
C
C
http://onsemi.com
f
f
2R
1(1)
1(1)
2(3)
2(3)
R
R
R
f
f
-
+
5(9)
14
1.0V
2.5V
2.5V
-m
5.0V Ref
EA
EA
m
Comp/Latch
+
+
S
R
1.0mA
1.0mA
Q
2R
2R
R
R
+
-
5(9)
5(9)
7(12)
36V
7(11)
6(10)
5(8)
3(5)
V
CC
R
V
S
in