UC3843BN STMicroelectronics, UC3843BN Datasheet - Page 8

• Manufacturer Part Number: UC3843BN
• Description: IC PWM CTRLR CURR MODE 8-MINIDIP
• Manufacturer: STMicroelectronics

Specifications of UC3843BN

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 500kHz
• Duty Cycle: 100%
• Voltage - Supply: 8.2 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: 500kHz
• Duty Cycle (max): 100 %
• Output Voltage: 5.1 V
• Output Current: 1000 mA (Max)
• Mounting Style: Through Hole
• Switching Frequency: 500 KHz
• Operating Supply Voltage: 30 V
• Maximum Operating Temperature: + 150 C
• Fall Time: 50 ns
• Minimum Operating Temperature: - 40 C
• Rise Time: 50 ns
• Synchronous Pin: No
• Topology: Boost or Flyback or Forward
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6786-5; UC3843BNST; UC3843BNST

Figure 16 : Under Voltage Lockout.
UC2842B/3B/4B/5B - UC3842B/3B/4B/5B
Figure 17 : Current Sense Circuit .
Peak current (i
A small RC filter may be required to suppress switch transients.
8/15
Figure 15 : Error Amp Configuration.
I
S max
V
i
1.0 V
R
R
s
S
S
) is determined by the formula
7
I
S
R
C
V
D95IN347
V
Z
OFF
ON
i
ON/OFF COMMAND
CURRENT
TO REST OF IC
SENSE
UC3842B
UC3844B
COMP
GND
16V
10V
Z
f
1
3
5
COMP
UC3843B
UC3845B
8.4V
7.6V
V
FB
ERROR
AMPL.
2
1
2.5V
<0.5mA
<17mA
D95IN346
+
-
I
2R
CC
R
V
OFF
1V
During UVLO, the Output is low
D95IN345
1mA
V
ON
COMPARATOR
CURRENT
SENSE
V
CC