©2012 Fairchild Semiconductor Corporation
www.fairchildsemi.com
Rev. 1.0.2
Features
• Output Current up to 1A
• Output Voltages of 5, 12V
• Thermal Overload Protection
• Short Circuit Protection
• Output Tran sistor Safe Operating Area Protection
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, mak-
ing it essentially indestructible. If adequate heat sinking is
provided, they can deliver over 1A output current. Although
designed primarily as fixed voltage regulators, these d evices
can be used with external components to obtain adjustable
voltages and currents.
D-PAK
1. Input 2. GND 3. Output
1
GND
Internal Block Digram
SERIES
PASS
ELEMENT
SOA
PROTECTION
ERROR
AMPLIFIER
THERMAL
PROTECTION
CURRENT
GENERATOR
REFERENCE
VOLTAGE
STARTING
CIRCUIT
OUTPUT
3
GND
2
INPUT
1
MC78XXE
3-Terminal 1A Positive Voltage Regulator
MC78XXE
2
Absolute Maximum Ratings
Electrical Characteristics (MC7805E)
(Refer to test circuit ,0C < TJ < 125C, IO = 500mA, VI = 10V, CI= 0.33F, CO= 0.1F, unless otherwise specified)
Note:
1. Load and line regulation are specified at constant junction temperature. Changes in Vo due to heating effects must be tak en
into account separately. Pulse testing with low duty is used.
2. These parameters, although guaranteed, are not 100% tested in production.
Parameter Symbol Value Unit
Input Voltage (for VO = 5V to 18V) VI35 V
Operating Temperature Range TOPR 0 ~ +125 C
Storage Temperature Range TSTG -65 ~ +150 C
Parameter Symbol Conditions MC7805E/LM7805E Unit
Min. Typ. Max.
Output Voltage VOTJ = +25C 4.8 5.0 5.2
5.0mA ≤Io ≤1.0A, PO ≤15W
VI = 7V to 20V 4.75 5.0 5.25 V
Line Regulation (Note1) Regline TJ = +25CVO = 7V to 25V - 4.0 100 mV
VI = 8V to 12V - 1.6 50
Load Regulation (Note1) Regload TJ = +25CIO = 5.0mA to1.5A - 9 100 mV
IO =250mA to
750mA -450
Quiescent Current IQTJ = +25C-5.08.0mA
Quiescent Current Change IQIO = 5mA to 1.0A - 0.03 0.5 mA
VI = 7V to 25V - 0.3 1.3
Output Voltage Drift (Note2) VO/TI
O = 5mA - -0.8 - mV/C
Output Noise Voltage VNf = 10Hz to 100kHz, TA = +25C-42-V/Vo
Ripple Rejection (Note2) RR f = 120Hz
VO = 8V to 18V 62 73 - dB
Dropout Voltage VDrop IO = 1A, TJ =+25C-2-V
Output Resistance (Note2) rOf = 1kHz - 15 - m
Short Circuit Current ISC VI = 35V, TA =+25C - 230 - mA
Peak Current (Note2) IPK TJ = +25C-2.2-A
MC78XXE
3
Electrical Characteristics (MC7812E)
(Refer to test circuit ,0C < TJ < 125C, IO = 500mA, VI =19V, CI= 0.33F, CO=0.1F, unless otherwise specified)
Note:
1. Load and line regulation are specified at constant jun ction temperature. Cha nges in VO due to heatin g effec ts must be ta ken
into account separately. Pulse testing with low duty is used.
2. These parameters, although guaranteed, are not 100% tested in production.
Parameter Symbol Conditions MC7812E Unit
Min. Typ. Max.
Output Voltage VOTJ = +25C 11.5 12 12.5 V
5.0mA IO 1.0A, PO 15W
VI = 14.5V to 27V 11.4 12 12.6
Line Regulation (Note1) Regline TJ = +25CVI = 1 4 . 5 V t o 30 V - 10 240 mV
VI = 16V to 22V - 3.0 120
Load Regulation (Note1) Regload TJ = +25CIO = 5mA to 1.5A - 11 240 mV
IO = 250mA to 750mA - 5.0 120
Quiescent Current IQTJ = +25C-5.18.0mA
Quiescent Current Change IQIO = 5mA to 1.0A - 0.1 0.5 mA
VI = 14.5V to 30V - 0.5 1.0
Output Voltage Drift (Note2) VO/TI
O = 5mA - -1 - mV/C
Output Noise Voltage VNf = 10Hz to 100kHz, TA = +25C-76-V/Vo
Ripple Rejection (Note2) RR f = 120Hz
VI = 15V to 25V 55 71 - dB
Dropout Voltage VDrop IO = 1A, TJ = +25C-2-V
Output Resistance (Note2) rOf = 1kHz - 18 - m
Short Circuit Current ISC VI = 35V, TA= +25C - 230 - mA
Peak Current (Note2) IPK TJ = +25C-2.2-A
MC78XXE
4
Typical Perfomance Characteristics
Figure 1. Quiescent Current
Figure 3. Output Voltage
Figure 2. Peak Output Current
Figure 4. Quiescent Current
I
MC78XXE
5
Typical Applications
Figure 5. DC Parameters
Figure 6. Load Regulation
Figure 7. Ripple Rejection
Figure 8. Fixed Output Regulator
MC78XXE Output
Input
13
2CO
0.1uF
CI
0.33uF
MC78XXE
1
2
3
Output
Input
0.33uF
RL270pF
100
VOOV
VO
30uS
2N6121
OR EQ.
MC78XXE
5.1
Output
Input
0.33uF
1
2
3
RL
470uF
+
120Hz
MC78XXE Output
Input
13
2CO
0.1uF
CI
0.33uF
MC78XXE
6
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 dista nce from power Supply filter.
(3) CO improves stability and transient response.
Figure 10. Circuit for Increasing Output Voltage
Figure 11. Adjustable Output Regulator (7 to 30V)
IO = VXX
R1+ IQ
1
2
3
0.1uF R1 VXX
Output
Input
0.33uF IQCO
RL
IO
MC78XXE
MC78XXE Output
Input
R1
R2
1
2
3
0.33uF
Cl Co
0.1uF VXX
IQ
IRI 5IQ
VO = VXX(1+R2/R1)+IQR2
MC7805E
IRI 5IQ
VO = VXX(1+R2/R1)+IQR2
LM741
Output
Input
2
3
6
4
1
2
3
Cl 0.33uF
Co
0.1uF
10k
_
+
MC78XXE
7
Figure 12. High Current Voltage Regulator
Figure 13. High Output Current with Short Circuit Protection
Figure 14. Tracking Voltage Regulator
IO = IREG+BQ1(IREG - VBEO1/R1)
R1 = VBEQ1
IREG - IQ1/BQ1
Output
Input
MC78XXE
IQ1
1
2
3
IREG
0.33uF 0.1uF
IO
R1
3
Q1 BD536
MC78XXE Output
Input
0.33uF 0.1uF
3
R1
Q2
RSC Q1
3
2
Q1 = TIP42
Q2 = TIP42
RSC=ISC
VBEQ2
MC78XXE 31
2
7
62
3
4
LM741
VO
-VO
-VIN
VI
COMMON
COMMON
0.33uF 0.1uF 4.7K
4.7K
TIP42
_
+
MC78XXE
8
Figure 15. Split Power Supply ( ±15V-1A)
Figure 16. Negative Output Voltage Circuit
Figure 17. Switching Regulator
MC7815E
MC7915E
2
3
1
1
23
+15V
-15V-20V
+20V
++
0.33uF
2.2uF 1uF
0.1uF 1N4001
1N4001
MC78XXE
0.1uF
Output
Input
+
1
2
MC78XXE
2
3
1
1mH Output
Input
10uF 0.33uF
Z1
2000uF
470
4.7
0.5
+
+
MC78XXE
9
Mechancal Dimensions
Package Dimensions in millimeters
D-PAK
MC78XXE
8/17/12 0.0m 001
Stock#DS400564
2012 Fairchild Semiconductor Corporation
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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.
www.fairchildsemi.com
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRC HILD DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUC T OR CIRCUIT DESCRIBED HEREIN ; NEITHER
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Ordering Information
Product Number Output Voltage Tolerance Package Operating Temperature
MC7805ECDTX ±4% D-PAK 0 ~ +125C
MC7812ECDTX
