Order this document by MC78T00/D
This family of fixed voltage regulators are monolithic integrated circuits
capable of driving loads in excess of 3.0 A. These three–terminal regulators
employ internal current limiting, thermal shutdown, and safe–area
compensation. Devices are available with improved specifications, including
a 2% output voltage tolerance, on AC–suffix 5.0, 12 and 15 V device types.
Although designed primarily as a fixed voltage regulator, these devices
can be used with external components to obtain adjustable voltages and
currents. This series of devices can be used with a series–pass transistor to
supply up to 15 A at the nominal output voltage.
THREE–AMPERE
POSITIVE FIXED
VOLTAGE REGULATORS
SEMICONDUCTOR
TECHNICAL DATA
• Output Current in Excess of 3.0 A
• Power Dissipation: 25 W
• No External Components Required
• Output Voltage Offered in 2% and 4% Tolerance*
• Thermal Regulation is Specified
• Internal Thermal Overload Protection
• Internal Short Circuit Current Limiting
• Output Transistor Safe–Area Compensation
T SUFFIX
PLASTIC PACKAGE
CASE 221A
Pin 1. Input
2. Ground
3. Output
2
MAXIMUM RATINGS (T = +25°C, unless otherwise noted.)
1
A
3
Rating
Symbol
Value
Unit
Input Voltage (5.0 V – 12 V)
Input Voltage (15 V)
V
I
35
40
Vdc
Heatsink surface is connected to Pin 2.
Power Dissipation and Thermal Characteristics
Plastic Package (Note 1)
T
= +25°C
P
InternallyLimited
A
D
Thermal Resistance, Junction–to–Air
= +25°C
R
P
R
65
InternallyLimited
2.5
°C/W
θJA
D
T
C
Thermal Resistance, Junction–to–Case
°C/W
°C
θJC
Storage Junction Temperature
T
stg
+150
Operating Junction Temperature Range
(MC78T00C, AC)
T
J
0 to +125
°C
DEVICE TYPE/NOMINAL OUTPUT VOLTAGE
MC78T05
MC78T08
5.0 V
8.0 V
MC78T12
MC78T15
12 V
15 V
NOTES: 1. Although power dissipation is internally limited, specifications apply only
for P ≤ P , P = 25 W.
O
max max
ORDERING INFORMATION
Operating
Simplified Application
V
Temperature
Range
O
Tol.
Device
Package
MC78TXX
Output
Input
T = 0° to
+125°C
Plastic
Power
MC78TXXCT
MC78TXXACT
4%
2%*
J
C
*
in
0.33µF
C **
O
T = –40° to
+125°C
Plastic
Power
MC78TXXBT#
MC78TXXABT# 2%*
4%
J
XX Indicates nominal voltage.
A common ground is required between the input and the output voltages. The input voltage must
remain typically 2.2 V above the output voltage even during the low point on the input ripple voltage.
* 2% regulators available in 5, 12 and 15 V devices.
XX these two digits of the type number indicate voltage.
# Automotive temperature range selections are avail-
able with special test conditions and additional
tests. Contact your local Motorola sales office for
information.
** C is required if regulator is located an appreciable distance from power supply filter.
in
** (See Applications Information for details.)
** C is not needed for stability; however, it does improve transient response.
O
Motorola, Inc. 1996
Rev 1
1
MOTOROLA ANALOG IC DEVICE DATA