UC3842A, UC3843A, UC2842A, UC2843A
V
7(12)
CC
V
V
CC
ref
5.0V
Reference
Undervoltage
Lockout
8(14)
R
R
V
ref
V
C
Undervoltage
Lockout
7(11)
R C
T
Output
T
Oscillator
6(10)
4(7)
Latching
PWM
Power
Ground
5(8)
Voltage
Feedback
Input
+
−
2(3)
Error
Amplifier
Current
Sense
Input
Output
Compensation
1(1)
3(5)
GND 5(9)
Pin numbers in parenthesis are for the D suffix SOIC−14 package.
Figure 1. Simplified Block Diagram
MAXIMUM RATINGS
Rating
Symbol
, V
Value
Unit
V
Bias and Driver Voltages (Zero Series Impedance, see also Total Device spec)
Total Power Supply and Zener Current
V
30
CC
C
(I + I )
30
mA
A
CC
Z
Output Current, Source or Sink (Note 1)
I
1.0
5.0
O
Output Energy (Capacitive Load per Cycle)
Current Sense and Voltage Feedback Inputs
Error Amp Output Sink Current
W
ꢀ J
V
V
in
− 0.3 to + 5.5
10
I
mA
O
Power Dissipation and Thermal Characteristics
D Suffix, Plastic Package
Maximum Power Dissipation @ T = 25°C
Thermal Resistance, Junction−to−Air
N Suffix, Plastic Package
P
862
145
mW
°C/W
A
D
R
ꢁ
JA
Maximum Power Dissipation @ T = 25°C
P
1.25
100
W
°C/W
A
D
Thermal Resistance, Junction−to−Air
R
ꢁ
JA
Operating Junction Temperature
T
+ 150
°C
°C
J
Operating Ambient Temperature
UC3842A, UC3843A
T
A
0 to + 70
UC2842A, UC2843A
− 25 to + 85
Storage Temperature Range
T
stg
− 65 to + 150
°C
Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit
values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied,
damage may occur and reliability may be affected.
1. Maximum Package power dissipation limits must be observed.
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