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MC78XXE
3-Terminal 1A Positive Voltage Regulator
Features
Description
•
•
•
•
•
The MC78XXE series of three terminal positive regulators
are available in the D-PAK package and with several fixed
output voltages, making them useful in a wide range of
applications. Each type employs internal current limiting,
thermal shut down and safe operating area protection, making it essentially indestructible. If adequate heat sinking is
provided, they can deliver over 1A output current. Although
designed primarily as fixed voltage regulators, these devices
can be used with external components to obtain adjustable
voltages and currents.
Output Current up to 1A
Output Voltages of 5, 12V
Thermal Overload Protection
Short Circuit Protection
Output Transistor Safe Operating Area Protection
D-PAK
GND
1
1. Input 2. GND 3. Output
Internal Block Digram
INPUT
SERIES
PASS
ELEMENT
1
CURRENT
GENERATOR
STARTING
CIRCUIT
REFERENCE
VOLTAGE
OUTPUT
3
SOA
PROTECTION
ERROR
AMPLIFIER
THERMAL
PROTECTION
GND
2
Rev. 1.0.2
©2012 Fairchild Semiconductor Corporation
MC78XXE
Absolute Maximum Ratings
Parameter
Symbol
Value
Unit
VI
35
V
Operating Temperature Range
TOPR
0 ~ +125
C
Storage Temperature Range
TSTG
-65 ~ +150
C
Input Voltage (for VO = 5V to 18V)
Electrical Characteristics (MC7805E)
(Refer to test circuit ,0C < TJ < 125C, IO = 500mA, VI = 10V, CI= 0.33F, CO= 0.1F, unless otherwise specified)
Parameter
Output Voltage
Symbol
VO
Conditions
MC7805E/LM7805E
Min.
Typ.
Max.
TJ = +25C
4.8
5.0
5.2
5.0mA ≤ Io ≤ 1.0A, PO ≤ 15W
VI = 7V to 20V
4.75
5.0
5.25
VO = 7V to 25V
-
4.0
100
VI = 8V to 12V
-
1.6
50
IO = 5.0mA to1.5A
-
9
100
IO =250mA to
750mA
-
4
50
Unit
V
Line Regulation (Note1)
Regline
TJ = +25C
Load Regulation (Note1)
Regload
TJ = +25C
IQ
TJ = +25C
-
5.0
8.0
IO = 5mA to 1.0A
-
0.03
0.5
VI = 7V to 25V
-
0.3
1.3
IO = 5mA
-
-0.8
-
mV/C
VN
f = 10Hz to 100kHz, TA = +25C
-
42
-
V/Vo
RR
f = 120Hz
VO = 8V to 18V
62
73
-
dB
IO = 1A, TJ =+25C
-
2
-
V
Quiescent Current
Quiescent Current Change
IQ
Output Voltage Drift (Note2)
VO/T
Output Noise Voltage
Ripple Rejection (Note2)
Dropout Voltage
VDrop
mV
mV
mA
mA
Output Resistance (Note2)
rO
f = 1kHz
-
15
-
m
Short Circuit Current
ISC
VI = 35V, TA =+25C
-
230
-
mA
Peak Current (Note2)
IPK
TJ = +25C
-
2.2
-
A
Note:
1. Load and line regulation are specified at constant junction temperature. Changes in Vo due to heating effects must be taken
into account separately. Pulse testing with low duty is used.
2. These parameters, although guaranteed, are not 100% tested in production.
2
MC78XXE
Electrical Characteristics (MC7812E)
(Refer to test circuit ,0C < TJ < 125C, IO = 500mA, VI =19V, CI= 0.33F, CO=0.1F, unless otherwise specified)
Parameter
Output Voltage
Symbol
VO
Conditions
MC7812E
Min.
Typ. Max.
TJ = +25C
11.5
12
12.5
5.0mA IO  1.0A, PO  15W
VI = 14.5V to 27V
11.4
12
12.6
VI = 14.5V to 30V
-
10
240
VI = 16V to 22V
-
3.0
120
IO = 5mA to 1.5A
-
11
240
IO = 250mA to 750mA
-
5.0
120
Unit
V
Line Regulation (Note1)
Regline
TJ = +25C
Load Regulation (Note1)
Regload
TJ = +25C
IQ
TJ = +25C
-
5.1
8.0
IO = 5mA to 1.0A
-
0.1
0.5
VI = 14.5V to 30V
-
0.5
1.0
IO = 5mA
-
-1
-
mV/C
-
76
-
V/Vo
55
71
-
dB
IO = 1A, TJ = +25C
-
2
-
V
Quiescent Current
Quiescent Current Change
IQ
Output Voltage Drift (Note2)
VO/T
Output Noise Voltage
VN
f = 10Hz to 100kHz, TA = +25C
Ripple Rejection (Note2)
RR
f = 120Hz
VI = 15V to 25V
Dropout Voltage
VDrop
mV
mV
mA
mA
Output Resistance (Note2)
rO
f = 1kHz
-
18
-
m
Short Circuit Current
ISC
VI = 35V, TA= +25C
-
230
-
mA
Peak Current (Note2)
IPK
TJ = +25C
-
2.2
-
A
Note:
1. Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be taken
into account separately. Pulse testing with low duty is used.
2. These parameters, although guaranteed, are not 100% tested in production.
3
MC78XXE
Typical Perfomance Characteristics
I
4
Figure 1. Quiescent Current
Figure 2. Peak Output Current
Figure 3. Output Voltage
Figure 4. Quiescent Current
MC78XXE
Typical Applications
3
1
MC78XXE
Input
Output
2
CO
0.1uF
CI
0.33uF
Figure 5. DC Parameters
3
1
MC78XXE
Output
Input
270pF
RL
2
VO
2N6121
OR EQ.
0.33uF
OV
VO
30uS
100
Figure 6. Load Regulation
5.1
3
1
MC78XXE
Input
Output
2
0.33uF
RL
470uF
+
120Hz
Figure 7. Ripple Rejection
3
1
MC78XXE
Input
Output
2
CI
0.33uF
CO
0.1uF
Figure 8. Fixed Output Regulator
5
MC78XXE
1
Input
3
MC78XXE
2
0.1uF
CO
IQ
0.33uF
Output
R1
VXX
IO
RL
VXX
+ IQ
R1
IO =
Figure 9. Constant Current Regulator
Notes:
(1) To specify an output voltage. substitute voltage value for "XX." A common ground is required between the input and the
Output voltage. The input voltage must remain typically 2.0V above the output voltage even during the low point on the input
ripple voltage.
(2) CI is required if regulator is located an appreciable distance from power Supply filter.
(3) CO improves stability and transient response.
1
Input
3
Output
MC78XXE
VXX
2
0.1uF
Cl
R1
Co
IQ
0.33uF
R2
IRI 5IQ
VO = VXX(1+R2/R1)+IQR2
Figure 10. Circuit for Increasing Output Voltage
1
Input
MC7805E
3
Output
2
Cl
0.33uF
_
6
2
0.1uF
LM741 3
4
+
Co
10k
IRI 5IQ
VO = VXX(1+R2/R1)+IQR2
Figure 11. Adjustable Output Regulator (7 to 30V)
6
MC78XXE
Q1 BD536
Input
IQ1
R1
3
1
MC78XXE
3
Output
IREG
IO
2
0.1uF
0.33uF
VBEQ1
R1 =
IREG - IQ1/BQ1
IO = IREG+BQ1(IREG - VBEO1/R1)
Figure 12. High Current Voltage Regulator
Q1
RSC
Input
Q2
3
R1
Output
MC78XXE
3
2
0.1uF
0.33uF
Q1 = TIP42
Q2 = TIP42
VBEQ2
RSC= I
SC
Figure 13. High Output Current with Short Circuit Protection
1
3
VO
MC78XXE
VI
2
0.33uF
0.1uF
4.7K
COMMON
7
6
_
COMMON
2
LM741
+
4
3
4.7K
-VIN
TIP42
-VO
Figure 14. Tracking Voltage Regulator
7
MC78XXE
1
3
MC7815E
+20V
+15V
2
1N4001
0.1uF
0.33uF
1uF +
+ 2.2uF
1N4001
1
MC7915E
2
-20V
3
-15V
Figure 15. Split Power Supply ( ±15V-1A)
Output
Input
+
0.1uF
2
1
MC78XXE
Figure 16. Negative Output Voltage Circuit
1mH
Output
Input
470
4.7
Z1
1
3
MC78XXE
+
0.33uF
2
10uF
0.5
Figure 17. Switching Regulator
8
+
2000uF
MC78XXE
Mechancal Dimensions
Package
Dimensions in millimeters
D-PAK
9
MC78XXE
Ordering Information
Product Number
MC7805ECDTX
MC7812ECDTX
Output Voltage Tolerance
Package
Operating Temperature
±4%
D-PAK
0 ~ +125C
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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