UC2844BN STMicroelectronics, UC2844BN Datasheet - Page 12

• Manufacturer Part Number: UC2844BN
• Description: IC PWM CTRLR CURR MODE 8-MINIDIP
• Manufacturer: STMicroelectronics
• Type: High Performance PWM Controllerr

Specifications of UC2844BN

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 500kHz
• Duty Cycle: 50%
• Voltage - Supply: 11 V ~ 25 V
• Buck: No
• Boost: Yes
• Flyback: Yes
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: -25°C ~ 85°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• Frequency-max: 500kHz
• Output Voltage Range: 4.95 V to 5.05 V
• Input Voltage Range: 30 V
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6135-5; UC2844BNST

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
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-
EA
V
8
4
2
1
CLAMP
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R
R
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·
+
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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
=
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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