UC3843BD ON Semiconductor, UC3843BD Datasheet - Page 9

• Manufacturer Part Number: UC3843BD
• Description: IC CTRLR CURRENT MODE HP 14SOIC
• Manufacturer: ON Semiconductor

Specifications of UC3843BD

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 275kHz
• Duty Cycle: 96%
• 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: 14-SOIC (3.9mm Width), 14-SOL
• Frequency-max: 275kHz
• Duty Cycle (max): 96 %
• Output Voltage: 4.9 V to 5.1 V
• Output Current: 1000 mA
• Mounting Style: SMD/SMT
• 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
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: UC3843BDOS

Capacitor C
Latch
“Set" Input
Output/
Compensation
Current Sense
Input
Latch
“Reset" Input
Output
T
Compensation
Feedback
Pin numbers adjacent to terminals are for the 8-pin dual-in-line package.
Pin numbers in parenthesis are for the D suffix SOIC-14 package.
R
C
Voltage
Output/
T
T
Input
8(14)
V
4(7)
2(3)
1(1)
ref
2.5V
Amplifier
Large R
Error
R
R
T
Oscillator
/Small C
+ 1.0mA
Figure 18. Representative Block Diagram
Internal
Bias
T
Figure 19. Timing Diagram
2R
GND
R
http://onsemi.com
5(9)
3.6V
1.0V
Current Sense
Reference
Comparator
Regulator
9
-
+
UVLO
V
ref
S
R
UVLO
V
Q
CC
PWM
Latch
V
CC
+
-
7(12)
(See
Text)
36V
Small R
= Sink Only Positive True Logic
V
7(11)
Output
6(10)
Power Ground
5(8)
Current Sense Input
3(5)
C
T
V
/Large C
CC
T
V
in
Q1
R
S