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KA78R05
Low Dropout Voltage Regulator
Features
•
•
•
•
•
1A / 5V Output low dropout voltage regulator
TO220 Full-Mold package (4PIN)
Overcurrent protection, Thermal shutdown
Overvoltage protection, Short-Circuit protection
With output disable function
Description
The KA78R05 is a low-dropout voltage regulator suitable
for various electronic equipments. It provides constant
voltage power source with TO-220 4 lead full mold package.
Dropout voltage of KA78R05 is below 0.5V in full rated
current(1A). This regulator has various function such as
peak current protection, thermal shut down, overvoltage
protection and output disable function.
TO-220F-4L
1
1. Vin 2. V
O
3. GND 4. Vdis
Internal Block Diagram
Q1
Vin
1
2
Vo
THERMAL SHUTDOWN
OVERVOLTAGE
PROTECTION
BANDGAP REFERENCE
-
+
R1
SOA PROTECTION
HIGH / LOW
Vdis
4
-
+
OUTPUT
ON / OFF
R2
1.4V
SHORT-CIRCUIT
SHORTCIRCUIT
PROTECTION
3
GND
Rev. 1.0.4
©2001 Fairchild Semiconductor Corporation
KA78R05
Absolute Maximum Ratings
Parameter
Input Voltage
Disable Voltage
Output Current
Power Dissipation 1
Power Dissipation 2
Junction Temperature
Operating Temperature
Thermal Resistance, Junction-to Case (Note2)
Thermal Resistance, Junction-to-Air (Note2)
Thermal Shutdown Temperature
Symbol
Vin
Vdis
Io
Pd1
Pd2
Tj
Topr
Rθjc
Rθja
Ttsd
Value
35
35
1.0
1.5
15
+150
-20 ~ +80
4.31
48.83
150
Unit
V
V
A
W
W
°C
°C
°C/W
°C/W
°C
Remark
-
-
-
No Heatsink
With Heatsink
-
-
-
-
-
Electrical Characteristics
(Vin = 7V, 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
5mA < Io < 1A
6V < Vin < 12V
note1
Io = 1A
Output Active
Output Disabled
Vdis = 2.7V
Vdis = 0.4V
Io = 0A
Conditions
-
Min.
4.88
-
-
45
-
2.0
-
-
-
-
Typ.
5
0.1
0.5
55
-
-
-
-
-
-
Max.
5.12
2.0
2.5
-
0.5
-
0.8
20
-0.4
10
Unit
V
%
%
dB
V
V
V
µA
mA
mA
Note:
1.These parameters, although guaranteed, are not 100% tested in production.
2. Junction -to -case thermal resistance test enviroments.
-. Pneumatic heat sink fixture.
-. Clamping pressure 60psi through 12mm diameter cylinder.
-. Thermal grease applied between PKG and heat sink fixture
2
KA78R05
Typical Perfomance Characteristics
7
50
Output voltage Vo(V)
6
5
RL=
8
i
Quescent current Iq(mA)
40
4
3
2
1
0
0
5
10
15
RL=5Ω
Ω
30
20
10
RL=
0
8
0
5
10
15
Input voltage Vin (V)
Input voltage Vin (V)
Figure 1. Output Voltage vs. Input Voltage
Figure 2. Quiescent Current vs. Input Voltage
7
5.06
Output voltage Vo(V)
5
4
3
2
1
0
Output voltage Vo(V)
0
0.5
1
1.5
2
2.5
3
6
5.04
5.02
5.00
4.98
4.96
4.94
4.92
-25
0
Disable voltage Vdis (V)
75
25
50
TEMPERATURE Tj(
o
C )
100
125
Figure 3. Output Voltage vs. Disable Voltage
Figure 4. Output Voltage vs. Temperature(Tj)
10
0.6
i
Quescent current Iq(mA)
Dropout voltage Vdrop(V)
8
0.5
0.4
Io=3A
0.3
2.0A
0.2
0.1
0.5A
1.0A
6
4
2
0
-25
0
25
50
75
100
125
0
-25
0
Junction temperature Tj(
o
C)
Junction temperature Tj(
o
C)
25
50
75
100
125
Figure 5. Quiescent Current vs. Temperature(Tj)
Figure 6. Dropout Voltage vs. Junction Temperature
3
KA78R05
Typical Perfomance Characteristics
(Continued)
20
100
Power dissipation P
D
D
(W)
Relative output voltage(%)
80
60
15
10
40
5
20
0
-25
0
0
25
50
75
100
125
0
0.5
1.0
1.5
2.0
2.5
3.0
TEMPERATURE T
a
(
o
C)
J
Output Current(A)
Figure 7. Power Dissipation vs. Temperature(Ta)
Figure 8. Overcurrent Protection Characteristics
(Typical Value)
4
KA78R05
Typical Application
Vin
1
+
Vo
2
+
3
GND
4
Vdis
Disable Signal
Figure 1. Application Circuit
• Ci is required if regulator is located an appreciable distance from power supply filter.
• Co improves stability and transient response.(Co > 47µF)
5
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