KA78R12 [FAIRCHILD]
Low Dropout Voltage Regulator; 低压差稳压器
| 型号： | KA78R12 |
| 厂家： | 
FAIRCHILD SEMICONDUCTOR |
| 描述： | Low Dropout Voltage Regulator |
| 文件： | 总8页 (文件大小：174K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
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KA78R12
Low Dropout Voltage Regulator
Features
Description
• 1A / 12V Output low dropout voltage regulator
• TO220 Full-Mold package (4PIN)
• Overcurrent protection, Thermal shutdown
• Overvoltage protection, Short-Circuit protection
• With output disable function
The KA78R12 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 KA78R12 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
1
1. Vin 2. Vo 3. GND 4. Vdis
Internal Block Diagram
Q1
Vin
1
2
Vo
OVERVOLTAGE
PROTECTION
THERMAL SHUTDOWN
BANDGAP REFERENCE
-
+
R1
SOA PROTECTION
HIGH / LOW
OUTPUT
ON / OFF
Vdis
4
-
+
R2
SHORT-CIRCUIT
PROTECTION
1.4V
3
GND
Rev. 1.0.1
©2001 Fairchild Semiconductor Corporation
KA78R12
Absolute Maximum Ratings
Parameter
Symbol
Vin
Value
35
Unit
V
Remark
Input Voltage
-
Disable Voltage
Vdis
Io
35
V
-
Output Current
1.0
A
-
Power Dissipation 1
Power Dissipation 2
Junction Temperature
Operating Temperature
Pd1
Pd2
Tj
1.5
W
No Heatsink
15
W
With Heatsink
+150
-20 ~ +80
°C
°C
-
-
Topr
Electrical Characteristics
(Vin =15V, Io = 0.5A, Ta = 25°C , unless otherwise specified)
Parameter
Output Voltage
Symbol
Vo
Conditions
Min.
Typ.
Max.
12.3
2.0
2.5
-
Unit
V
-
11.7
12
Load Regulation
Rload
Rline
RR
5mA < Io < 1A
-
0.1
%
Line Regulation
13V < Vin < 29V
note1
-
45
-
0.5
%
Ripple Rejection Ratio
Dropout Voltage
55
-
dB
V
Vdrop
VdisH
VdisL
IdisH
IdisL
Iq
Io = 1A
0.5
-
Disable Voltage High
Disable Voltage Low
Disable Bias Current High
Disable Bias Current Low
Quiescent Current
Output Active
Output Disabled
Vdis = 2.7V
Vdis = 0.4V
Io = 0A
2.0
-
-
V
-
0.8
20
V
-
-
mA
mA
mA
-
-
-0.4
10
-
-
Note:
1.These parameters, although guaranteed, are not 100% tested in production.
2
KA78R12
Typical Perfomance Characteristics
17.5
15.0
50
40
12.5
RL=
30
20
10
0
10.0
7.5
RL=12
W
RL=
5.0
2.5
0
0
5
10
15
20
25
5
10
15
20
25
0
Input voltage Vin (V)
Input voltage Vin (V)
Figure 1.Output Voltage vs. Input Voltage
Figure 2.Quiescent Current vs. Input Voltage
17.5
12.06
15.0
12.5
12.04
12.02
12.00
10.0
7.5
11.98
11.96
11.94
11.92
5.0
2.5
0
0
0.5
1
1.5
2
2.5
3
75
TEMPERATURETj(oC)
-25
0
25
50
100
125
Disable voltage Vdis (V)
Figure 3.Output Voltage vs. Disable Voltage
Figure 4.Output Voltage vs. Temperature(Tj)
10
8
0.6
0.5
0.4
6
4
2
0
Io=1A
0.3
0.2
0.1
0.75A
0.5A
0.25A
75
0
-25
-25
0
25
50
75
100
125
0
25
50
100
125
Junction temperature Tj(oC)
Junction temperature Tj(oC)
Figure 5.Quiescent Current vs. Temperature(Tj)
Figure 6.Dropout Voltage vs. Junction Temperature
3
KA78R12
Typical Perfomance Characteristics (continued)
20
15
100
80
60
10
5
40
20
0
0
-25
0
0.5
1.0
1.5
2.0
2.5
3.0
75
TEMPERATURE TaJ(oC)
0
25
50
100
125
Output Current(A)
Figure 8. Overcurrent Protection Characteristics
(Typical Value)
Figure 7.Power Dissipation vs. Temperature(Ta)
4
KA78R12
Typical Application
Vo
Vin
1
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 > 47mF)
5
KA78R12
Mechanical Dimensions
Package
Dimensions in millimeters
TO-220F-4L
6
KA78R12
Ordering Information
Product Number
Package
TO-220F-4L
Operating Temperature
KA78R12
-20°C to + 80°C
7
KA78R12
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’ S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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4/26/01 0.0m 001
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Ó 2001 Fairchild Semiconductor Corporation
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