UC3842A, UC3843A, UC2842A, UC2843A
V
CC
V
ref
8(14)
R
R
R
T
C
T
4(7)
Voltage
Feedback
Input
2(3)
Output
Compensation
1(1)
+
−
7(12)
5.0V
Reference
V
ref
Undervoltage
Lockout
Oscillator
Latching
PWM
Error
Amplifier
V
CC
Undervoltage
Lockout
V
C
7(11)
Output
6(10)
Power
Ground
5(8)
Current
Sense
3(5) Input
GND
5(9)
Pin numbers in parenthesis are for the D suffix SOIC−14 package.
Figure 1. Simplified Block Diagram
MAXIMUM RATINGS
Rating
Bias and Driver Voltages (Zero Series Impedance, see also Total Device spec)
Total Power Supply and Zener Current
Output Current, Source or Sink (Note 1)
Output Energy (Capacitive Load per Cycle)
Current Sense and Voltage Feedback Inputs
Error Amp Output Sink Current
Power Dissipation and Thermal Characteristics
D Suffix, Plastic Package
Maximum Power Dissipation @ T
A
= 25°C
Thermal Resistance, Junction−to−Air
N Suffix, Plastic Package
Maximum Power Dissipation @ T
A
= 25°C
Thermal Resistance, Junction−to−Air
Operating Junction Temperature
Operating Ambient Temperature
UC3842A, UC3843A
UC2842A, UC2843A
Storage Temperature Range
Symbol
V
CC
, V
C
(I
CC
+ I
Z
)
I
O
W
V
in
I
O
Value
30
30
1.0
5.0
− 0.3 to + 5.5
10
Unit
V
mA
A
mJ
V
mA
P
D
R
qJA
P
D
R
qJA
T
J
T
A
862
145
1.25
100
+ 150
0 to + 70
− 25 to + 85
mW
°C/W
W
°C/W
°C
°C
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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