2001 Fairchild Semiconductor Corporation
www.fairchildsemi.com
Rev. 1.0.0
Features
Output current in excess of 3.0A
Output transistor safe operating area compensation
Power dissipation :25W
Internal short circuit current limiting
Internal thermal overload protection
Output voltage offered in 4% tolerance
No external components required
Output voltage of 5, 12 and 15V
Description
This family of fixed voltage regulators are monolithic
integrated circuit capable of driving loads in excess of 3.0 A.
TO-220
1.Input 2. GND 3. Output
1
Internal Block Diagram
KA78TXX
3-Terminal 3A Positive Voltage Regulator
KA78TXX
2
Absolute Maximum Ratings
Electrical Characteristics(KA78T05)
(V
I
= 10V, I
O
= 3.0 A, 0
C
T
J
+125
C, Po
P
MAX
, unless otherwise specified.)
Note:
1. Load and line regulation are specified at constant junction temperature. Change in Vo due heating effects must be taken into
account separately. Pulse testing with low duty is used .( P
MAX
= 25W)
Parameter
Symbol
Value
Unit
Input Voltage (for V
O
= 5V to 12V)
(for V
O
= 15V)
V
I
35
40
V
V
Power Dissipation
PD
Internally limited
-
Thermal Resistance, Junction to Air
Tc = +25
C
R
JA
65
C/W
Thermal Resistance ,Junction to Case
R
JC
2.5
C/W
Operating Junction Temperature Range
T
J
0 ~ +150
C
Storage Temperature Range
T
STG
-65 ~ +150
C
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Unit
Output Voltage
Vo
5mA
Io
3.0A , T
J
= +25
C
7.3V
VI
20V, 5mA
Io
2.0A
4.8
4.75
5.0
5.0
5.2
5.25
V
Line Regulation (Note1)
V
O
7.2V
VI
35V , Io=5mA, T
J
=+25
C
7.2V
VI
35V , Io=1.0A, T
J
= +25
C
7.5V
VI
20V, Io =2.0A
8.0V
VI
12V, Io =3.0A
-
3.0
2.5
mV
Load Regulation (Note1)
V
O
5mA
Io
3.0A , T
J
= +25
C
5mA
Io
3.0A
-
10
15
30
80
mV
mV
Thermal Regulation
REG
T
Pulse =10ms, P = 20W
TA = +25
C
-
0.002
0.03
%Vo/W
Quiescent Current
I
Q
5mA
Io
3.0A , T
J
= +25
C
5mA
Io
3.0A
-
3.5
4.0
5.0
6.0
mA
mA
Quiescent Current
Change
I
Q
7.2V
VI
35V, Io = 5mA
T
J
= +25
C ;
7.5V
VI
20V, Io =2.0A ;
5mA
Io
3.0A
-
0.1
0.8
mA
Ripple Rejection
RR
f = 120Hz, 8V
V
I
18V, I
o
=
2.0A
-
75
-
dB
Dropout Voltage
V
D
Io = 3A ,T
J
= +25
C
-
2.2
2.5
V
Output Noise Voltage
V
N
T
A
= +25
C, 10Hz
f
100KHz
-
10
-
V/Vo
Peak Output Current
I
PK
T
A
= +25
C
-
5.0
-
A
Output Resistance
Ro
f = 1.0kHz
-
2.0
-
m
Short Circuit Current Limit
Isc
VI = 35V, T
J
=+25
C
-
1.5
2.5
A
Average Temperature
Coefficient of Output
Voltage
V
O
/
T Io = 5.0mA
-
0.2
-
mV/
C
KA78TXX
3
Electrical Characteristics(KA78T12)
(V
I
= 19V, I
O
= 3.0 A, 0
C
T
J
+125
C, Po
P
MAX
, unless otherwise specified.)
Note:
1. Load and line regulation are specified at constant junction temperature. Change in Vo due heating effects must be taken into
account separately. Pulse testing with low duty is used. ( P
MAX
= 25W)
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Unit
Output Voltage
Vo
5mA
Io
3.0A , T
J
=+25
C
14.5V
VI
27V, 5mA
Io
2.0A
11.5
11.4
12
12
12.5
12.8
V
Line Regulation (Note1)
V
O
14.5V
VI
35V , Io=5mA, T
J
=+25
C
14.5V
VI
35V , Io=1.0A, T
J
=+25
C
14.9V
VI
28V, Io =2.0A
16V
VI
22V, Io =3.0A
-
6.0
45
mV
Load Regulation (Note1)
V
O
5mA
Io
3.0A , T
J
=+25
C
5mA
Io
3.0A
-
10
15
30
80
mV
mV
Thermal Regulation
REG
T
Pulse =10ms, P = 20W
TA = +25
C
-
0.002
0.03
%Vo/W
Quiescent Current
I
Q
5mA
Io
3.0A , T
J
=+25
C
5mA
Io
3.0A
-
3.5
4.0
5.0
6.0
mA
mA
Quiescent Current
Change
I
Q
14.5V
VI
35V, Io = 5mA
T
J
=+25
C ;
14.9V
VI
27V, Io =2.0A ;
5mA
Io
3.0A
-
0.1
0.8
mA
Ripple Rejection
RR
f = 120Hz, 15V
V
I
25V, Io
=
2.0A
57
67
-
dB
Dropout Voltage
V
D
Io = 3A ,T
J
=+25
C
-
2.2
2.5
V
Output Noise Voltage
V
N
T
A
=+25
C, 10Hz
f
100KHz
-
10
-
V/Vo
Peak Output Current
I
PK
T
A
=+25
C
-
5.0
-
A
Output Resistance
Ro
f = 1.0kHz
-
2.0
-
m
Short Circuit Current Limit
Isc
VI = 35V, T
J
=+25
C
-
1.5
2.5
A
Average Temperature
Coefficient of Output
Voltage
V
O
/
T Io = 5.0mA
-
0.5
-
mV/
C
KA78TXX
4
Electrical Characteristics(KA78T15)
(V
I
= 23V, I
O
= 3.0 A, 0
C
T
J
+125
C, Po
P
MAX
, unless otherwise specified.)
Note:
1. Load and line regulation are specified at constant junction temperature. Change in Vo due heating effects must be taken into
account separately. Pulse testing with low duty is used. ( P
MAX
= 25W)
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Unit
Output Voltage
Vo
5mA
Io
3.0A , T
J
=+25
C
17.5V
VI
30V, 5mA
Io
2.0A
14.4
14.25
15
15
15.6
15.75
V
Line Regulation (Note1)
V
O
17.6V
VI
40V , Io=5mA, T
J
=+25
C
17.6V
VI
40V , Io=1.0A, T
J
=+25
C
18V
VI
30V, Io =2.0A
20V
VI
26V, Io =3.0A
-
7.5
55
mV
Load Regulation (Note1)
V
O
5mA
Io
3.0A , T
J
=+25
C
5mA
Io
3.0A
-
10
15
30
80
mV
mV
Thermal Regulation
REG
T
Pulse =10ms, P = 20W
TA = +25
C
-
0.002
0.03
%Vo/W
Quiescent Current
I
Q
5mA
Io
3.0A , T
J
=+25
C
5mA
Io
3.0A
-
3.5
4.0
5.0
6.0
mA
mA
Quiescent Current
Change
I
Q
17.6V
VI
40V, Io = 5mA
T
J
=+25
C ;
18V
VI
30V, Io =2.0A ;
5mA
Io
3.0A
-
0.1
0.8
mA
Ripple Rejection
RR
f = 120Hz, 18.5V
V
I
28.5V, Io
=
2.0A
55
65
-
dB
Dropout Voltage
V
D
Io = 3A ,T
J
=+25
C
-
2.2
2.5
V
Output Noise Voltage
V
N
T
A
=+25
C, 10Hz
f
100KHz
-
10
-
V/Vo
Peak Output Current
I
PK
T
A
=+25
C
-
5.0
-
A
Output Resistance
Ro
f = 1.0kHz
-
2.0
-
m
Short Circuit Current Limit
Isc
VI = 40V, T
J
=+25
C
-
1.0
2.0
A
Average Temperature
Coefficient of Output
Voltage
V
O
/
T Io = 5.0mA
-
0.5
-
mV/
C
KA78TXX
5
Typical Application
Notes:
1. To specify an output voltage, substitute voltage value for "XX".
2. Bypass Capacitors are recommend for optimum stability and transient response and should be located as close as possible
to the regulator
KA78TXX
INPUT
OUTPUT
3
2
1
0.33
F
0. 1
F
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