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PRODUCT SPECIFICATION
RC4391
2
Pin Assignments
LBR
LBD
C
X
GND
V
FB
V
REF
+V
S
L
X
8
65-3471-02
7
6
5
1
2
3
4
Note:
1. The maximum allowable supply voltage (+V
S
) in inverting applications will be reduced by the value of the negative output
voltage, unless an external power transistor is used in place of Q1.
Thermal Characteristics
Parameter
Internal Power Dissipation
Supply Voltage
1
Operating Temperature
Conditions
Min
Typ
Max
500
+30
70
85
125
150
125
175
375
468
833
300
300
Unit
mW
V
°
C
°
C
°
C
°
C
°
C
°
C
mA
mW
mW
mW
°
C
(Pin 6 to Pin 4 or Pin 6 to Pin 5)
RC4391
RV4391
RM4391
0
-25
-55
-65
Storage Temperature
Junction Temperature
PDIP, SOIC
CerDIP
Peak
PDIP
CerDIP
SOIC
(10 seconds)
Switch Current (I
MAX
)
P
D
T
A
<50C
Lead Soldering Temperature
8-Lead Plastic DIP
—
160
°
C/W
6.25 mW/
°
C
8-Lead Ceramic DIP
45
°
C/W
150
°
C/W
8.33 mW/
°
C
Small Outline SO-8
—
240
°
C/W
4.17 mW/
°
C
Therm. Res
q
JC
Therm. Res.
q
JA
For T
A
>50C Derate at
Pin Descriptions
Pin
Number
1
2
3
4
5
6
7
8
Pin Function Description
Low Battery Resistor (LBR)
Low Battery Detector (LBD)
Timing Capacitor (C
X
)
Ground
External Inductor (L
X
)
+Supply Voltage (+V
S
)
+1.25V Reference Voltage (V
REF
)
Feedback Voltage (V
FB
)