ON MC78T12CT 3.0 a positive voltage regulator Datasheet

MC78T00 Series
3.0 A Positive Voltage
Regulators
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 V, 12 V 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.
• 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
• Pb−Free Packages are Available
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3A
POSITIVE FIXED
VOLTAGE REGULATORS
MARKING
DIAGRAMS
TO−220
T SUFFIX
CASE 221A
1
2
3
MC
78TxxyzT
AWLYWW
Pin 1. Input
2. Ground*
3. Output
*Heatsink surface is connected to Pin 2.
Input
Cin*
0.33 F
MC78TXX
Output
CO**
D2PAK−3
CASE 936
MC
78TxxyzD2T
AWLYWW
Figure 1. Simplified Application
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.
XX these two digits of the type number indicate voltage.
** Cin is required if regulator is located an appreciable distance from power supply filter.
** (See Applications Information for details.)
** CO is not needed for stability; however, it does improve transient response.
MC = Specific Device Code
xx = Voltage Option
y = “A” letter for precise 2% regulators, not
used for standard 4% regulators.
z = temperature range, “B” for wide
temperature range, −40°C to +125°C, “C”
for standard temperature range,
0°C to +125°C.
A = Assembly Location
WL= Wafer Lot
Y = Year
W = Work Week
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 10 of this data sheet.
 Semiconductor Components Industries, LLC, 2004
March, 2004 − Rev. 4
1
Publication Order Number:
MC78T00/D
MC78T00 Series
MAXIMUM RATINGS (TA = +25°C, unless otherwise noted.)
Rating
Symbol
Value
Unit
VI
35
40
Vdc
Power Dissipation and Thermal Characteristics
Plastic Package (Note 1)
TA = +25°C
Thermal Resistance, Junction−to−Air
TC = +25°C
Thermal Resistance, Junction−to−Case
PD
RJA
PD
RJC
Internally Limited
65
Internally Limited
2.5
°C/W
Storage Junction Temperature
Tstg
+150
°C
Operating Junction Temperature Range
(MC78T00C, AC)
TJ
0 to +125
°C
Input Voltage (5.0 V − 12 V)
Input Voltage (15 V)
°C/W
Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit
values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied,
damage may occur and reliability may be affected.
1. Although power dissipation is internally limited, specifications apply only for PO ≤ Pmax, Pmax = 25 W.
ELECTRICAL CHARACTERISTICS (Vin = 10 V, IO = 3.0 A, 0°C ≤ TJ ≤ 125°C, PO ≤ Pmax (Note 2), unless otherwise noted.)
MC78T05AC
Characteristics
Output Voltage
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A;
5.0 mA ≤ IO ≤ 2.0 A, 7.3 Vdc ≤ Vin ≤ 20 Vdc)
Symbol
Min
Typ
Max
Min
Typ
Max
4.9
4.8
5.0
5.0
5.1
5.2
4.8
4.75
5.0
5.0
5.2
5.25
−
3.0
25
−
3.0
25
−
−
10
15
30
80
−
−
10
15
30
80
−
0.001
0.01
−
0.002
0.03
−
−
3.5
4.0
5.0
6.0
−
−
3.5
4.0
5.0
6.0
VO
Line Regulation (Note 3)
(7.2 Vdc ≤ Vin ≤ 35 Vdc, IO = 5.0 mA, TJ = +25°C;
7.2 Vdc ≤ Vin ≤ 35 Vdc, IO = 1.0 A, TJ = +25°C;
8.0 Vdc ≤ Vin ≤ 12 Vdc, IO = 3.0 A, TJ = +25°C;
7.5 Vdc ≤ Vin ≤ 20 Vdc, IO = 1.0 A)
Regline
Load Regulation (Note 3)
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A)
Regload
Thermal Regulation
(Pulse = 10 ms, P = 20 W, TA = +25°C)
Regtherm
Quiescent Current
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A)
MC78T05C
Unit
Vdc
mV
mV
IB
%VO/W
mA
Quiescent Current Change
(7.2 Vdc ≤ Vin ≤ 35 Vdc, IO = 5.0 mA, TJ = +25°C;
5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C;
7.5 Vdc ≤ Vin ≤ 20 Vdc, IO = 1.0 A)
IB
−
0.3
1.0
−
0.3
1.0
mA
Ripple Rejection
(8.0 Vdc ≤ Vin ≤ 18 Vdc, f = 120 Hz,
IO = 2.0 A, TJ = 25°C)
RR
62
75
−
62
75
−
dB
Dropout Voltage (IO = 3.0 A, TJ = +25°C)
Vin−VO
−
2.2
2.5
−
2.2
2.5
Vdc
Output Noise Voltage
(10 Hz ≤ f ≤ 100 kHz, TJ = +25°C)
Vn
−
10
−
−
10
−
V/VO
Output Resistance (f = 1.0 kHz)
RO
−
2.0
−
−
20
−
m
2. Although power dissipation is internally limited, specifications apply only for PO ≤ Pmax, Pmax = 25 W.
3. Line and load 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 cycle is used.
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MC78T00 Series
ELECTRICAL CHARACTERISTICS (Vin = 10 V, IO = 3.0 A, 0°C ≤ TJ ≤ 125°C, PO ≤ Pmax (Note 2), unless otherwise noted.)
MC78T05AC
MC78T05C
Symbol
Min
Typ
Max
Min
Typ
Max
Unit
Short Circuit Current Limit
(Vin = 35 Vdc, TJ = +25°C)
ISC
−
1.5
−
−
1.5
−
A
Peak Output Current (TJ = +25°C)
Imax
−
5.0
−
−
5.0
−
A
TCVO
−
0.2
−
−
0.2
−
mV/°C
Characteristics
Average Temperature Coefficient of Output Voltage
(IO = 5.0 mA)
2. Although power dissipation is internally limited, specifications apply only for PO ≤ Pmax, Pmax = 25 W.
3. Line and load 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 cycle is used.
ELECTRICAL CHARACTERISTICS (Vin = 13 V, IO = 3.0 A, 0°C ≤ TJ ≤ 125°C, PO ≤ Pmax (Note 4), unless otherwise noted.)
MC78T08C
Characteristics
Symbol
Output Voltage
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A;
5.0 mA ≤ IO ≤ 2.0 A, 10.4 Vdc ≤ Vin ≤ 23 Vdc)
Min
Typ
Max
7.7
7.6
8.0
8.0
8.3
8.4
−
4.0
35
−
−
10
15
30
80
−
0.002
0.03
−
−
3.5
4.0
5.0
6.0
VO
Line Regulation (Note 5)
(10.3 Vdc ≤ Vin ≤ 35 Vdc, IO = 5.0 mA, TJ = +25°C
10.3 Vdc ≤ Vin ≤ 35 Vdc, IO = 1.0 A, TJ = +25°C
11 Vdc ≤ Vin ≤ 17 Vdc, IO = 3.0 A, TJ = +25°C
10.7 Vdc ≤ Vin ≤ 23 Vdc, IO = 1.0 A)
Regline
Load Regulation (Note 5)
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A)
Regload
Thermal Regulation
(Pulse = 10 ms, P = 20 W, TA = +25°C)
Regtherm
Quiescent Current
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A)
Unit
Vdc
mV
mV
IB
%VO/W
mA
Quiescent Current Change
(10.3 Vdc ≤ Vin ≤ 35 Vdc, IO = 5.0 mA, TJ = +25°C;
5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C;
10.7 Vdc ≤ Vin ≤ 23 Vdc, IO = 1.0 A)
IB
−
0.3
1.0
mA
Ripple Rejection
(11 Vdc ≤ Vin ≤ 21 Vdc, f = 120 Hz, IO = 2.0 A, TJ = 25°C)
RR
60
71
−
dB
Vin−VO
−
2.2
2.5
Vdc
Output Noise Voltage
(10 Hz ≤ f ≤ 100 kHz, TJ = +25°C)
Vn
−
10
−
V/VO
Output Resistance (f = 1.0 kHz)
RO
−
2.0
−
m
Short Circuit Current Limit
(Vin = 35 Vdc, TJ = +25°C)
ISC
−
1.5
−
A
Peak Output Current (TJ = +25°C)
Imax
−
5.0
−
A
TCVO
−
0.3
−
mV/°C
Dropout Voltage (IO = 3.0 A, TJ = +25°C)
Average Temperature Coefficient of Output Voltage (IO = 5.0 mA)
4. Although power dissipation is internally limited, specifications apply only for PO ≤ Pmax, Pmax = 25 W.
5. Line and load 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 cycle is used.
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MC78T00 Series
ELECTRICAL CHARACTERISTICS (Vin = 17 V, IO = 3.0 A, 0°C ≤ TJ ≤ 125°C, PO ≤ Pmax (Note 6), unless otherwise noted.)
MC78T12AC
Characteristics
Output Voltage
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A,
5.0 mA ≤ IO ≤ 2.0 A, 14.5 Vdc ≤ Vin ≤ 27 Vdc)
Symbol
Typ
Max
Min
Typ
Max
11.75
11.5
12
12
12.25
12.5
11.5
11.4
12
12
12.5
12.6
−
6.0
45
−
6.0
45
−
−
10
15
30
80
−
−
10
15
30
80
−
0.001
0.01
−
0.002
0.03
−
−
3.5
4.0
5.0
6.0
−
−
3.5
4.0
5.0
6.0
VO
Line Regulation (Note 7)
(14.5 Vdc ≤ Vin ≤ 35 Vdc, IO = 5.0 mA, TJ = +25°C;
14.5 Vdc ≤ Vin ≤ 35 Vdc, IO = 1.0 A, TJ = +25°C;
16 Vdc ≤ Vin ≤ 22 Vdc, IO = 3.0 A, TJ = +25°C;
14.9 Vdc ≤ Vin ≤ 27 Vdc, IO = 1.0 A)
Regline
Load Regulation (Note 7)
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A)
Regload
Thermal Regulation
(Pulse = 10 ms, P = 20 W, TA = +25°C)
Regtherm
Quiescent Current
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A)
MC78T12C
Min
Unit
Vdc
mV
mV
IB
%VO/W
mA
Quiescent Current Change
(14.5 Vdc ≤ Vin ≤ 35 Vdc, IO = 5.0 mA, TJ = +25°C;
5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C;
14.9 Vdc ≤ Vin ≤ 27 Vdc, IO = 1.0 A)
IB
−
0.3
1.0
−
0.3
1.0
mA
Ripple Rejection
(15 Vdc ≤ Vin ≤ 25 Vdc, f = 120 Hz,
IO = 2.0 A, TJ = 25°C)
RR
57
67
−
57
67
−
dB
Vin − VO
−
2.2
2.5
−
2.2
2.5
Vdc
Output Noise Voltage
(10 Hz ≤ f ≤ 100 kHz, TJ = +25°C)
Vn
−
10
−
−
10
−
V/VO
Output Resistance (f = 1.0 kHz)
RO
−
2.0
−
−
20
−
m
Short Circuit Current Limit
(Vin = 35 Vdc, TJ = +25°C)
ISC
−
1.5
−
−
1.5
−
A
Peak Output Current (TJ = +25°C)
Imax
−
5.0
−
−
5.0
−
A
Average Temperature Coefficient
of Output Voltage (IO = 5.0 mA)
TCVO
−
0.5
−
−
0.5
−
mV/°C
Dropout Voltage (IO = 3.0 A, TJ = +25°C)
6. Although power dissipation is internally limited, specifications apply only for PO ≤ Pmax, Pmax = 25 W.
7. Line and load 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 cycle is used.
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MC78T00 Series
ELECTRICAL CHARACTERISTICS (Vin = 20 V, IO = 3.0 A, 0°C ≤ TJ ≤ 125°C, PO ≤ Pmax (Note 8), unless otherwise noted.)
MC78T15AC
Characteristics
Output Voltage
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A;
5.0 mA ≤ IO ≤ 2.0 A, 17.5 Vdc ≤ Vin ≤ 30 Vdc)
Symbol
Typ
Max
Min
Typ
Max
14.7
14.4
15
15
15.3
15.6
14.4
14.25
15
15
15.6
15.75
−
7.5
55
−
7.5
55
−
−
10
15
30
80
−
−
10
15
30
80
−
0.001
0.01
−
0.002
0.03
−
−
3.5
4.0
5.0
6.0
−
−
3.5
4.0
5.0
6.0
VO
Line Regulation (Note 9)
(17.6 Vdc ≤ Vin ≤ 40 Vdc, IO = 5.0 mA, TJ = +25°C;
17.6 Vdc ≤ Vin ≤ 40 Vdc, IO = 1.0 A, TJ = +25°C;
20 Vdc ≤ Vin ≤ 26 Vdc, IO = 3.0 A, TJ = +25°C;
18 Vdc ≤ Vin ≤ 30 Vdc, IO = 1.0 A)
Regline
Load Regulation (Note 9)
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A)
Regload
Thermal Regulation
(Pulse = 10 ms, P = 20 W, TA = +25°C)
Regtherm
Quiescent Current
(5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C)
(5.0 mA ≤ IO ≤ 3.0 A)
MC78T15C
Min
Unit
Vdc
mV
mV
IB
%VO/W
mA
Quiescent Current Change
(17.6 Vdc ≤ Vin ≤ 40 Vdc, IO = 5.0 mA, TJ = +25°C;
5.0 mA ≤ IO ≤ 3.0 A, TJ = +25°C;
18 Vdc ≤ Vin ≤ 30 Vdc, IO = 1.0 A)
IB
−
0.3
1.0
−
0.3
1.0
mA
Ripple Rejection
(18.5 Vdc ≤ Vin ≤ 28.5 Vdc, f = 120 Hz,
IO = 2.0 A, TJ = 25°C)
RR
55
65
−
55
65
−
dB
Dropout Voltage (IO = 3.0 A, TJ = +25°C)
Vin−VO
−
2.2
2.5
−
2.2
2.5
Vdc
Vn
−
10
−
−
10
−
V/VO
Output Resistance (f = 1.0 kHz)
RO
−
2.0
−
−
20
−
m
Short Circuit Current Limit
(Vin = 40 Vdc, TJ = +25°C)
ISC
−
1.0
−
−
1.0
−
A
Peak Output Current (TJ = +25°C)
Imax
−
5.0
−
−
5.0
−
A
TCVO
−
0.6
−
−
0.6
−
mV/°C
Output Noise Voltage
(10 Hz ≤ f ≤ 100 kHz, TJ = +25°C)
Average Temperature Coefficient of Output Voltage
(IO = 5.0 mA)
8. Although power dissipation is internally limited, specifications apply only for PO ≤ Pmax, Pmax = 25 W.
9. Line and load 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 cycle is used.
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MC78T00 Series
The performance of a voltage regulator is specified by its
immunity to changes in load, input voltage, power
dissipation, and temperature. Line and load regulation are
tested with a pulse of short duration (< 100 s) and are
strictly a function of electrical gain. However, pulse widths
of longer duration (> 1.0 ms) are sufficient to affect
temperature gradients across the die. These temperature
gradients can cause a change in the output voltage, in
addition to changes caused by line and load regulation.
Longer pulse widths and thermal gradients make it
desirable to specify thermal regulation.
Thermal regulation is defined as the change in output
voltage caused by a change in dissipated power for a
specified time, and is expressed as a percentage output
voltage change per watt. The change in dissipated power
can be caused by a change in either the input voltage or the
load current. Thermal regulation is a function of IC layout
and die attach techniques, and usually occurs within 10 ms
of a change in power dissipation. After 10 ms, additional
changes in the output voltage are due to the temperature
coefficient of the device.
Figure 1 shows the line and thermal regulation response
of a typical MC78T05AC to a 20 W input pulse. The
variation of the output voltage due to line regulation is
labeled ➀ and the thermal regulation component is labeled
➁. Figure 2 shows the load and thermal regulation response
of a typical MC78T05AC to a 20 W load pulse. The output
voltage variation due to load regulation is labeled ➀ and the
thermal regulation component is labeled ➁.
∆ V O , OUTPUT
V in , INPUT VOLTAGE DEVIATION (V)
VOLTAGE (V)
∆ V O , OUTPUT
VOLTAGE DEVIATION (V)
VOLTAGE REGULATOR PERFORMANCE
2
1
8.0
I O , OUTPUT
CURRENT (A)
(2.0 mV/DIV)
18
2
1
2
2.0
0
t, TIME (2.0 ms/DIV)
Vout = 5.0 V
Vin = 8.0 V → 18 V → 8.0 V
Iout = 2.0 A
t, TIME (2.0 ms/DIV)
Vout = 5.0 V
Vin = 15
Iout = 0 A → 2.0 A → 0 A
1 = Regline = 2.4 mV
2 = Regtherm = 0.0015%VO/W
Figure 1. MC78T05AC Line and Thermal Regulation
Q1
1.0k
(2.0 mV/DIV)
2
1 = Regline = 4.4 mV
2 = Regtherm = 0.0015%VO/W
Figure 2. MC78T05AC Load and Thermal Regulation
Input
1.0k
Q2
Q20
Q22
210
6.7V
Q21
16k
Q24
Q9
Q3
Q4
3.0k
3.6k
Q19
5.6k
6.4k
Q5
10pF
Q23
5.0 VO
3.9k
2.0k
Q6
Q7
Q11
Output
6.0k
Q17
Q18
Q15
Q13
6.0k
200
0.12
40
pF
Q12
2.6k 8.0−15VO
Q27
13
50
520
Q26
300
Q16
Q10
Q25
200
1.0k
Q8
300
100
Q14
Gnd
2.8k
Figure 3. Representative Schematic Diagram
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6
MC78T00 Series
100
r O , OUTPUT IMPEDANCE (Ω
)
NORMALIZED OUTPUT VOLTAGE
1.02
Vin − Vout = 10 V
Iout = 100 mA
1.0
.98
−90
−50
−10
30
70
110
TJ, JUNCTION TEMPERATURE (°C)
150
10−1
10−2
10−3
10−4
1.0
190
Figure 4. Temperature Stability
RR, RIPPLE REJECTION (dB)
Iout = 50 mA
80
Iout = 1.5 A
60
Vout = 5.0 V
Vin = 10 V
CO = 0
TJ = 25°C
40
4.0
10
100 1.0 k
10 k
100 k
1.0 M
10 M
1.0 k
10 k 100 k
f, FREQUENCY (Hz)
1.0 M
10 M 100 M
Vout = 5.0 V
Vin = 10 V
CO = 0
f = 120 Hz
TJ = 25°C
40
0.1
1.0
10
Iout, OUTPUT CURRENT (A)
Figure 6. Ripple Rejection versus Frequency
Figure 7. Ripple Rejection versus
Output Current
5.0
TJ = 25°C
3.0
TJ = 125°C
2.0
TJ = 0°C
TJ = 25°C
TJ = 125°C
0
60
f, FREQUENCY (Hz)
TJ = 0°C
1.0
80
30
0.01
100 M
IB , QUIESCENT CURRENT (mA)
RR, RIPPLE REJECTION (dB)
100
100
20
1.0
IB , QUIESCENT CURRENT (mA)
10
Figure 5. Output Impedance
100
0
Vout = 5.0 V
Vin = 7.5 V
Iout = 1.0 A
CO = 0
TJ = 25°C
10
20
30
TJ = 25°C
3.0
TJ = 125°C
2.0
1.0
0
0.01
40
TJ = 0°C
4.0
Vin−Vout = 5.0 V
0.1
1.0
Vin, INPUT VOLTAGE (Vdc)
Iout, OUTPUT CURRENT (A)
Figure 8. Quiescent Current versus
Input Voltage
Figure 9. Quiescent Current versus
Output Current
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7
10
MC78T00 Series
Iout = 3.0 A
2.0
Iout = 1.0 A
1.5
Iout = 0.5 A
1.0
VO = 50 mV
−10
30
70
110
150
4.0
2.0
190
TJ = 0°C
TJ = 25°C
TJ = 125°C
10
20
30
Vin−VO, INPUT−OUTPUT VOLTAGE (Vdc)
Figure 10. Dropout Voltage
Figure 11. Peak Output Current
Vout = 5.0 V
Iout = 150 mA
CO = 0
TJ = 25°C
0.6
0.4
0.2
0
−0.2
−0.4
−0.6
1.0
0.5
0
0
TJ, JUNCTION TEMPERATURE (°C)
0.8
0
6.0
0
−50
I out , OUTPUT ∆ V out , OUTPUT VOLTAGE
DEVIATION (V)
CURRENT (A)
∆ V out , OUTPUT VOLTAGE
DEVIATION (V)
0.5
−90
∆ Vin , INPUT VOLTAGE
CHANGE (V)
I max, PEAK OUTPUT CURRENT (A)
8.0
10
20
30
Vin = 10 V
CO = 0
TJ = 25°C
0.2
0.1
0
−0.1
−0.2
−0.3
1.5
1.0
0.5
0
0
40
10
20
30
t, TIME (s)
Figure 12. Line Transient Response
Figure 13. Load Transient Response
40
30
Maximum Ambient
Temperature
SA of Heatsinks
1.3°C/W
2.4°C/W
Infinite
Heatsink
20
3.3°C/W
10 6.3°C/W
10.5°C
0
25
50
75
100
TA, AMBIENT TEMPERATURE (°C)
Figure 14. Maximum Average Power
Dissipation for MC78T00CT, ACT
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8
40
0.3
t, TIME (s)
P D(AV) , MAXIMUM AVERAGE POWER DISSIPATION (W)
V in −Vout , INPUT TO OUTPUT
VOLTAGE DIFFERENTIAL (Vdc)
2.5
125
40
MC78T00 Series
APPLICATIONS INFORMATION
Design Considerations
regulator is connected to the power supply filter with long
wire lengths, or if the output load capacitance is large. An
input bypass capacitor should be selected to provide good
high frequency characteristics to insure stable operation
under all load conditions. A 0.33 F or larger tantalum,
mylar, or other capacitor having low internal impedance at
high frequencies should be chosen. The bypass capacitor
should be mounted with the shortest possible leads directly
across the regulator’s input terminals. Normally good
construction techniques should be used to minimize ground
loops and lead resistance drops since the regulator has no
external sense lead.
The MC78T00 Series of fixed voltage regulators are
designed with Thermal Overload Protection that shuts
down the circuit when subjected to an excessive power
overload condition, Internal Short Circuit Protection that
limits the maximum current the circuit will pass, and
Output Transistor Safe−Area Compensation that reduces
the output short circuit current as the voltage across the pass
transistor is increased.
In many low current applications, compensation
capacitors are not required. However, it is recommended
that the regulator input be bypassed with a capacitor if the
MC78T05
Input
Input
R
0.33F
IO
Output
MC78T05
Constant
Current to
Grounded Load
7
−
0.33F
The MC78T05 regulator can also be used as a current source
when connected as above. In order to minimize dissipation the
MC78T05 is chosen in this application. Resistor R determines
the current as follows:
2
0.1F
6
+
1.0k
3
10k
4
MC1741
I0 5.0 V IB
R
VO, 8.0 V to 20 V
Vin − VO ≥ 2.5 V
IB 0.7 mA over line, load and Temperature changes
IB 3.5 mA
For example, a 2.0 A current source would require R to be a 2.5 ,
10W resistor and the output voltage compliance would be the input
voltage less 7.0 V.
The addition of an operational amplifier allows adjustment to higher or
intermediate values while retaining regulation characteristics. The
minimum voltage obtainable with this arrangement is 3.0 V greater
than the regulator voltage.
Figure 15. Current Regulator
Figure 16. Adjustable Output Regulator
Input
Rsc
2N4398
or Equiv.
2N4398 or Equiv
R
MC78TXX
MJ2955
or Equiv.
Output
R
MC78TXX
Output
1.0F
1.0F
0.1F
XX = 2 digits of type number indicating voltage.
The MC78T00 series can be current boosted with a PNP transistor. The
2N4398 provides current to 15 A. Resistor R in conjunction with the VBE
of the PNP determines when the pass transistor begins conducting; this
circuit is not short circuit proof. Input−output differential voltage
minimum is increased by the VBE of the pass transistor.
XX = 2 digits of type number indicating voltage.
The circuit of Figure 17 can be modified to provide supply protection
against short circuits by adding a short circuit sense resistor, RSC, and
an additional PNP transistor. The current sensing PNP must be able to
handle the short circuit current of the three−terminal regulator.
Therefore, an eight−ampere power transistor is specified.
Figure 17. Current Boost Regulator
Figure 18. Current Boost With
Short Circuit Protection
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9
MC78T00 Series
ORDERING INFORMATION
Device
VO Tol.
Nominal
Output Voltage
Operating
Temperature Range
Package
Shipping†
MC78T05ABT
2%*
TJ = −40°C TO +125°C
TO−220
50 Units / Rail
MC78T05ACT
2%*
TJ = 0°C TO +125°C
TO−220
50 Units / Rail
MC78T05ACTG
2%*
TJ = 0°C TO +125°C
TO−220
(Pb−Free)
50 Units / Rail
MC78T05BT
4%
TJ = −40°C TO +125°C
TO−220
50 Units / Rail
MC78T05BTG
4%
TJ = −40°C TO +125°C
TO−220
(Pb−Free)
50 Units / Tubes
MC78T05CD2T
4%
TJ = 0°C TO +125°C
D2PAK−3
50 Units / Rail
800 / Tape & Reel
5.0 V
MC78T05CD2TR4
4%
TJ = 0°C TO +125°C
D2PAK−3
MC78T05CT
4%
TJ = 0°C TO +125°C
TO−220
50 Units / Rail
MC78T05CTG
4%
TJ = 0°C TO +125°C
TO−220
(Pb−Free)
50 Units / Rail
MC78T08CT
4%
8.0 V
TJ = 0°C TO +125°C
TO−220
50 Units / Rail
MC78T12ACT
2%*
TJ = 0°C TO +125°C
TO−220
50 Units / Rail
MC78T12BT
4%
12 V
TJ = −40°C TO +125°C
TO−220
50 Units / Rail
MC78T12CT
4%
TJ = 0°C TO +125°C
TO−220
50 Units / Rail
MC78T15ABT
2%*
TJ = −40°C TO +125°C
TO−220
50 Units / Rail
MC78T15ACT
2%*
TJ = 0°C TO +125°C
TO−220
50 Units / Rail
MC78T15CT
4%
TJ = 0°C TO +125°C
TO−220
50 Units / Rail
15 V
NOTE:
Automotive temperature range selections are available with special test conditions and additional tests. Contact your local
ON Semiconductor sales office for information.
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
*2% regulators available in 5.0 V, 12 V and 15 V devices.
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10
MC78T00 Series
PACKAGE DIMENSIONS
TO−220
T SUFFIX
CASE 221A−09
ISSUE AA
−T−
B
SEATING
PLANE
C
F
T
S
4
DIM
A
B
C
D
F
G
H
J
K
L
N
Q
R
S
T
U
V
Z
A
Q
1 2 3
U
H
K
Z
L
R
V
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION Z DEFINES A ZONE WHERE ALL
BODY AND LEAD IRREGULARITIES ARE
ALLOWED.
J
G
D
N
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11
INCHES
MIN
MAX
0.570
0.620
0.380
0.405
0.160
0.190
0.025
0.035
0.142
0.147
0.095
0.105
0.110
0.155
0.018
0.025
0.500
0.562
0.045
0.060
0.190
0.210
0.100
0.120
0.080
0.110
0.045
0.055
0.235
0.255
0.000
0.050
0.045
−−−
−−−
0.080
MILLIMETERS
MIN
MAX
14.48
15.75
9.66
10.28
4.07
4.82
0.64
0.88
3.61
3.73
2.42
2.66
2.80
3.93
0.46
0.64
12.70
14.27
1.15
1.52
4.83
5.33
2.54
3.04
2.04
2.79
1.15
1.39
5.97
6.47
0.00
1.27
1.15
−−−
−−−
2.04
MC78T00 Series
PACKAGE DIMENSIONS
D2PAK−3
CASE 936−03
ISSUE B
−T−
K
OPTIONAL
CHAMFER
A
TERMINAL 4
E
U
S
B
F
1
2
3
V
H
M
J
D
0.010 (0.254) M T
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. TAB CONTOUR OPTIONAL WITHIN DIMENSIONS
A AND K.
4. DIMENSIONS U AND V ESTABLISH A MINIMUM
MOUNTING SURFACE FOR TERMINAL 4.
5. DIMENSIONS A AND B DO NOT INCLUDE MOLD
FLASH OR GATE PROTRUSIONS. MOLD FLASH
AND GATE PROTRUSIONS NOT TO EXCEED
0.025 (0.635) MAXIMUM.
L
P
N
G
DIM
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
S
U
V
R
C
SOLDERING FOOTPRINT*
8.38
0.33
1.016
0.04
10.66
0.42
INCHES
MIN
MAX
0.386
0.403
0.356
0.368
0.170
0.180
0.026
0.036
0.045
0.055
0.051 REF
0.100 BSC
0.539
0.579
0.125 MAX
0.050 REF
0.000
0.010
0.088
0.102
0.018
0.026
0.058
0.078
5 REF
0.116 REF
0.200 MIN
0.250 MIN
MILLIMETERS
MIN
MAX
9.804 10.236
9.042
9.347
4.318
4.572
0.660
0.914
1.143
1.397
1.295 REF
2.540 BSC
13.691 14.707
3.175 MAX
1.270 REF
0.000
0.254
2.235
2.591
0.457
0.660
1.473
1.981
5 REF
2.946 REF
5.080 MIN
6.350 MIN
5.08
0.20
3.05
0.12
17.02
0.67
D2PAK
SCALE 3:1
mm inches
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any
liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental
damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over
time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under
its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body,
or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death
may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees,
subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of
personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part.
SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
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LITERATURE FULFILLMENT:
N. American Technical Support: 800−282−9855 Toll Free
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USA/Canada
P.O. Box 5163, Denver, Colorado 80217 USA
Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada Japan: ON Semiconductor, Japan Customer Focus Center
2−9−1 Kamimeguro, Meguro−ku, Tokyo, Japan 153−0051
Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada
Phone: 81−3−5773−3850
Email: [email protected]
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ON Semiconductor Website: http://onsemi.com
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For additional information, please contact your
local Sales Representative.
MC78T00/D
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