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Fairchild Semiconductor |
KA78R08
Low Dropout Voltage Regulator
www.fairchildsemi.com
Features
• 1A / 8V Output low dropout voltage regulator
• TO220 Full-Mold package (4Pin)
• Overcurrent protection, Thermal shutdown
• Overvoltage protection, Short-Circuit protection
www.DataSheet4•U.cWomith output disable function
Description
The KA78R08 is a low-dropout voltage regulator suitable
for various electronic equipments. It provides constant volt-
age power source with TO-220 4 lead full mold package.
Dropout voltage of KA78R08 is below 0.5V in full rated
current(1A). This regulator has various function such as
peak current protection, thermal shut down, overvoltage pro-
tection and output disable function.
TO-220F-4L
Internal Block Diagram
Vin 1
THERMAL SHUTDOWN
BANDGAP REFERENCE
HIGH / LOW
Vdis 4
-
+
OUTPUT
ON / OFF
1.4V
1
1.Vin 2. V O 3. GND 4. Vdis
OVERVOLTAGE
PROTECTION
-
+
SOA PROTECTION
Q1
R1
SHSOHROTR-TCCIIRRCCUIITT
PROTECTION
R2
2 Vo
©2001 Fairchild Semiconductor Corporation
3
GND
Rev. 1.0.1
KA78R08
Absolute Maximum Ratings
Parameter
Input Voltage
Disable Voltage
Output Current
Power Dissipation 1
Power Dissipation 2
Junction Temperature
Operating Temperature
www.DataSheet4U.com
Symbol
Vin
Vdis
Io
Pd1
Pd2
Tj
Topr
Value
35
35
1.0
1.5
15
+150
-20 ~ +80
Electrical Characteristics
(Vin =10V, Io = 0.5A, Ta = 25°C , unless otherwise specified)
Parameter
Output Voltage
Load Regulation
Line Regulation
Ripple Rejection Ratio
Dropout Voltage
Disable Voltage High
Disable Voltage Low
Disable Bias Current High
Disable Bias Current Low
Quiescent Current
Symbol
Vo
Rload
Rline
RR
Vdrop
VdisH
VdisL
IdisH
IdisL
Iq
Conditions
-
5mA < Io < 1A
9V < Vin < 25V
note1
Io = 1A
Output Active
Output Disabled
Vdis = 2.7V
Vdis = 0.4V
Io = 0A
Note:
1.These parameters, although guaranteed, are not 100% tested in production.
Unit
V
V
A
W
W
°C
°C
Remark
-
-
-
No Heatsink
With Heatsink
-
-
Min.
7.8
-
-
45
-
2.0
-
-
-
-
Typ.
8
0.1
0.5
55
-
-
-
-
-
-
Max.
8.2
2.0
2.5
-
0.5
-
0.8
20
-0.4
10
Unit
V
%
%
dB
V
V
V
µA
mA
mA
2
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