UC3845N ON Semiconductor, UC3845N Datasheet - Page 8

• Manufacturer Part Number: UC3845N
• Description: IC CTRLR CURRENT MODE HP 8DIP
• Manufacturer: ON Semiconductor
• Type: High Performance Current Mode Controllersr

Specifications of UC3845N

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 60kHz
• Duty Cycle: 50%
• Voltage - Supply: 8.2 V ~ 25 V
• Buck: No
• Boost: Yes
• Flyback: Yes
• Inverting: Yes
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• Frequency-max: 60kHz
• Output Voltage Range: 4.9 V to 5.1 V
• Input Voltage Range: 30 V
• Operating Temperature Range: 0 C to + 70 C
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: UC3845NOS

Current Sense
Compensation
‘‘Reset’’ Input
Voltage Feedback
Input
Capacitor C
Output/
Input
‘‘Set’’ Input
Latch
Output
Compensation
Latch
Output
C
R
T
T
T
V
ref
8(14)
4(7)
2(3)
1(1)
Pin numbers in parenthesis are for the D suffix SOIC−14 package.
2.5V
Amplifier
+
−
Error
Large R
R
R
+
Oscillator
T
1.0mA
/Small C
Internal
Bias
Figure 16. Representative Block Diagram
T
2R
GND
Figure 17. Timing Diagram
R
5(9)
http://onsemi.com
3.6V
1.0V
Current Sense
Comparator
Reference
Regulator
+
−
8
−
+
+
−
UVLO
V
ref
S
R
T
UVLO
V
Q
Q
CC
PWM
Latch
+
−
V
CC
−
+
−
+
=
7(12)
Sink Only
Positive True Logic
36V
Small R
Output
Current Sense Input
V
Power Ground
3(5)
7(11)
6(10)
5(8)
C
T
/Large C
V
CC
T
V
in
Q1
R
S