LM1117/LM1117I
800mA Low-Dropout Linear Regulator
General Description
The LM1117 is a series of low dropout voltage regulators
with a dropout of 1.2V at 800mA of load current. It has the
same pin-out as National Semiconductor’s industry standard
LM317.
The LM1117 is available in an adjustable version, which can
set the output voltage from 1.25V to 13.8V with only two
external resistors. In addition, it is also available in five fixed
voltages, 1.8V, 2.5V, 2.85V, 3.3V, and 5V.
The LM1117 offers current limiting and thermal shutdown. Its
circuit includes a zener trimmed bandgap reference to as-
sure output voltage accuracy to within ±1%.
The LM1117 series is available in LLP, TO-263, SOT-223,
TO-220, and TO-252 D-PAK packages. A minimum of 10µF
tantalum capacitor is required at the output to improve the
transient response and stability.
Features
nAvailable in 1.8V, 2.5V, 2.85V, 3.3V, 5V, and Adjustable
Versions
nSpace Saving SOT-223 and LLP Packages
nCurrent Limiting and Thermal Protection
nOutput Current 800mA
nLine Regulation 0.2% (Max)
nLoad Regulation 0.4% (Max)
nTemperature Range
— LM1117 0˚C to 125˚C
— LM1117I −40˚C to 125˚C
Applications
n2.85V Model for SCSI-2 Active Termination
nPost Regulator for Switching DC/DC Converter
nHigh Efficiency Linear Regulators
nBattery Charger
nBattery Powered Instrumentation
Typical Application
Active Terminator for SCSI-2 Bus
10091905
Fixed Output Regulator
10091928
April 2006
LM1117/LM1117I 800mA Low-Dropout Linear Regulator
© 2006 National Semiconductor Corporation DS100919 www.national.com
Ordering Information
Package Temperature
Range
Part Number Packaging Marking Transport Media NSC
Drawing
3-lead
SOT-223
0˚C to +125˚C LM1117MPX-ADJ N03A Tape and Reel MP04A
LM1117MPX-1.8 N12A Tape and Reel
LM1117MPX-2.5 N13A Tape and Reel
LM1117MPX-2.85 N04A Tape and Reel
LM1117MPX-3.3 N05A Tape and Reel
LM1117MPX-5.0 N06A Tape and Reel
−40˚C to +125˚C LM1117IMPX-ADJ N03B Tape and Reel
LM1117IMPX-3.3 N05B Tape and Reel
LM1117IMPX-5.0 N06B Tape and Reel
3-lead TO-220 0˚C to +125˚C LM1117T-ADJ LM1117T-ADJ Rails T03B
LM1117T-1.8 LM1117T-1.8 Rails
LM1117T-2.5 LM1117T-2.5 Rails
LM1117T-2.85 LM1117T-2.85 Rails
LM1117T-3.3 LM1117T-3.3 Rails
LM1117T-5.0 LM1117T-5.0 Rails
3-lead TO-252 0˚C to +125˚C LM1117DTX-ADJ LM1117DT-ADJ Tape and Reel TD03B
LM1117DTX-1.8 LM1117DT-1.8 Tape and Reel
LM1117DTX-2.5 LM1117DT-2.5 Tape and Reel
LM1117DTX-2.85 LM1117DT-2.85 Tape and Reel
LM1117DTX-3.3 LM1117DT-3.3 Tape and Reel
LM1117DTX-5.0 LM1117DT-5.0 Tape and Reel
−40˚C to +125˚C LM1117IDTX-ADJ LM1117IDT-ADJ Tape and Reel
LM1117IDTX-3.3 LM1117IDT-3.3 Tape and Reel
LM1117IDTX-5.0 LM1117IDT-5.0 Tape and Reel
8-lead LLP 0˚C to +125˚C LM1117LDX-ADJ 1117ADJ Tape and Reel LDC08A
LM1117LDX-1.8 1117-18 Tape and Reel
LM1117LDX-2.5 1117-25 Tape and Reel
LM1117LDX-2.85 1117-28 Tape and Reel
LM1117LDX-3.3 1117-33 Tape and Reel
LM1117LDX-5.0 1117-50 Tape and Reel
−40˚C to 125˚C LM1117ILDX-ADJ 1117IAD Tape and Reel
LM1117ILDX-3.3 1117I33 Tape and Reel
LM1117ILDX-5.0 1117I50 Tape and Reel
TO-263 0˚C to +125˚C LM1117SX-ADJ LM1117SADJ Tape and Reel TS3B
LM1117SX-2.85 LM1117S2.85 Tape and Reel
LM1117SX-3.3 LM1117S3.3 Tape and Reel
LM1117SX-5.0 LM1117S5.0 Tape and Reel
LM1117/LM1117I
www.national.com 2
Block Diagram
10091901
Connection Diagrams
SOT-223
10091904
Top View
TO-220
10091902
Top View
TO-252
10091938
Top View
TO-263
10091944
Top View
10091945
Side View
LLP
10091946
When using the LLP package
Pins 2,3&4must be connected together and
Pins 5,6&7must be connected together
Top View
LM1117/LM1117I
www.national.com3
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Maximum Input Voltage (V
IN
to GND) 20V
Power Dissipation (Note 2) Internally Limited
Junction Temperature (T
J
)
(Note 2) 150˚C
Storage Temperature Range -65˚C to 150˚C
Lead Temperature
TO-220 (T) Package 260˚C, 10 sec
SOT-223 (IMP) Package 260˚C, 4 sec
ESD Tolerance (Note 3) 2000V
Operating Ratings (Note 1)
Input Voltage (V
IN
to GND) 15V
Junction Temperature Range (T
J
)(Note 2)
LM1117 0˚C to 125˚C
LM1117I −40˚C to 125˚C
LM1117 Electrical Characteristics
Typicals and limits appearing in normal type apply for T
J
= 25˚C. Limits appearing in Boldface type apply over the entire junc-
tion temperature range for operation, 0˚C to 125˚C.
Symbol Parameter Conditions Min
(Note 5)
Typ
(Note 4)
Max
(Note 5) Units
V
REF
Reference Voltage LM1117-ADJ
I
OUT
= 10mA, V
IN
-V
OUT
= 2V, T
J
= 25˚C
10mA ≤I
OUT
≤800mA, 1.4V ≤V
IN
-V
OUT
≤10V
1.238
1.225
1.250
1.250
1.262
1.270
V
V
V
OUT
Output Voltage LM1117-1.8
I
OUT
= 10mA, V
IN
= 3.8V, T
J
= 25˚C
0≤I
OUT
≤800mA, 3.2V ≤V
IN
≤10V
1.782
1.746
1.800
1.800
1.818
1.854
V
V
LM1117-2.5
I
OUT
= 10mA, V
IN
= 4.5V, T
J
= 25˚C
0≤I
OUT
≤800mA, 3.9V ≤V
IN
≤10V
2.475
2.450
2.500
2.500
2.525
2.550
V
V
LM1117-2.85
I
OUT
= 10mA, V
IN
= 4.85V, T
J
= 25˚C
0≤I
OUT
≤800mA, 4.25V ≤V
IN
≤10V
0≤I
OUT
≤500mA, V
IN
= 4.10V
2.820
2.790
2.790
2.850
2.850
2.850
2.880
2.910
2.910
V
V
V
LM1117-3.3
I
OUT
= 10mA, V
IN
=5VT
J
= 25˚C
0≤I
OUT
≤800mA, 4.75V≤V
IN
≤10V
3.267
3.235
3.300
3.300
3.333
3.365
V
V
LM1117-5.0
I
OUT
= 10mA, V
IN
= 7V, T
J
= 25˚C
0≤I
OUT
≤800mA, 6.5V ≤V
IN
≤12V
4.950
4.900
5.000
5.000
5.050
5.100
V
V
∆V
OUT
Line Regulation
(Note 6)
LM1117-ADJ
I
OUT
= 10mA, 1.5V ≤V
IN
-V
OUT
≤13.75V 0.035 0.2 %
LM1117-1.8
I
OUT
= 0mA, 3.2V ≤V
IN
≤10V
16mV
LM1117-2.5
I
OUT
= 0mA, 3.9V ≤V
IN
≤10V
16mV
LM1117-2.85
I
OUT
= 0mA, 4.25V ≤V
IN
≤10V 1 6mV
LM1117-3.3
I
OUT
= 0mA, 4.75V ≤V
IN
≤15V 1 6mV
LM1117-5.0
I
OUT
= 0mA, 6.5V ≤V
IN
≤15V 1 10 mV
LM1117/LM1117I
www.national.com 4
LM1117 Electrical Characteristics (Continued)
Typicals and limits appearing in normal type apply for T
J
= 25˚C. Limits appearing in Boldface type apply over the entire junc-
tion temperature range for operation, 0˚C to 125˚C.
Symbol Parameter Conditions Min
(Note 5)
Typ
(Note 4)
Max
(Note 5) Units
∆V
OUT
Load Regulation
(Note 6)
LM1117-ADJ
V
IN
-V
OUT
= 3V, 10 ≤I
OUT
≤800mA 0.2 0.4 %
LM1117-1.8
V
IN
= 3.2V, 0 ≤I
OUT
≤800mA
110 mV
LM1117-2.5
V
IN
= 3.9V, 0 ≤I
OUT
≤800mA
110 mV
LM1117-2.85
V
IN
= 4.25V, 0 ≤I
OUT
≤800mA 1 10 mV
LM1117-3.3
V
IN
= 4.75V, 0 ≤I
OUT
≤800mA 1 10 mV
LM1117-5.0
V
IN
= 6.5V, 0 ≤I
OUT
≤800mA 1 15 mV
V
IN
-V
OUT
Dropout Voltage
(Note 7)
I
OUT
= 100mA 1.10 1.20 V
I
OUT
= 500mA 1.15 1.25 V
I
OUT
= 800mA 1.20 1.30 V
I
LIMIT
Current Limit V
IN
-V
OUT
= 5V, T
J
= 25˚C 800 1200 1500 mA
Minimum Load
Current (Note 8)
LM1117-ADJ
V
IN
= 15V 1.7 5mA
Quiescent Current LM1117-1.8
V
IN
≤15V
510 mA
LM1117-2.5
V
IN
≤15V
510 mA
LM1117-2.85
V
IN
≤10V 5 10 mA
LM1117-3.3
V
IN
≤15V 5 10 mA
LM1117-5.0
V
IN
≤15V 5 10 mA
Thermal Regulation T
A
= 25˚C, 30ms Pulse 0.01 0.1 %/W
Ripple Regulation f
RIPPLE
=1 20Hz, V
IN
-V
OUT
=3VV
RIPPLE
=1V
PP
60 75 dB
Adjust Pin Current 60 120 µA
Adjust Pin Current
Change
10 ≤I
OUT
≤800mA,
1.4V ≤V
IN
-V
OUT
≤10V 0.2 5µA
Temperature Stability 0.5 %
Long Term Stability T
A
= 125˚C, 1000Hrs 0.3 %
RMS Output Noise (% of V
OUT
), 10Hz ≤f≤10kHz 0.003 %
Thermal Resistance
Junction-to-Case
3-Lead SOT-223 15.0 ˚C/W
3-Lead TO-220 3.0 ˚C/W
3-Lead TO-252 10 ˚C/W
Thermal Resistance
Junction-to-Ambient
(No air flow)
3-Lead SOT-223 (No heat sink) 136 ˚C/W
3-Lead TO-220 (No heat sink) 79 ˚C/W
3-Lead TO-252 (Note 9) (No heat sink) 92 ˚C/W
3-Lead TO-263 55 ˚C/W
8-Lead LLP(Note 10) 40 ˚C/W
LM1117/LM1117I
www.national.com5
LM1117I Electrical Characteristics
Typicals and limits appearing in normal type apply for T
J
= 25˚C. Limits appearing in Boldface type apply over the entire junc-
tion temperature range for operation, −40˚C to 125˚C.
Symbol Parameter Conditions Min
(Note 5)
Typ
(Note 4)
Max
(Note 5) Units
V
REF
Reference Voltage LM1117I-ADJ
I
OUT
= 10mA, V
IN
-V
OUT
= 2V, T
J
= 25˚C
10mA ≤I
OUT
≤800mA, 1.4V ≤V
IN
-V
OUT
≤10V
1.238
1.200
1.250
1.250
1.262
1.290
V
V
V
OUT
Output Voltage LM1117I-3.3
I
OUT
= 10mA, V
IN
= 5V, T
J
= 25˚C
0≤I
OUT
≤800mA, 4.75V ≤V
IN
≤10V
3.267
3.168
3.300
3.300
3.333
3.432
V
V
LM1117I-5.0
I
OUT
= 10mA, V
IN
= 7V, T
J
= 25˚C
0≤I
OUT
≤800mA, 6.5V ≤V
IN
≤12V
4.950
4.800
5.000
5.000
5.050
5.200
V
V
∆V
OUT
Line Regulation
(Note 6)
LM1117I-ADJ
I
OUT
= 10mA, 1.5V ≤V
IN
-V
OUT
≤13.75V 0.035 0.3 %
LM1117I-3.3
I
OUT
= 0mA, 4.75V ≤V
IN
≤15V 1 10 mV
LM1117I-5.0
I
OUT
= 0mA, 6.5V ≤V
IN
≤15V 1 15 mV
∆V
OUT
Load Regulation
(Note 6)
LM1117I-ADJ
V
IN
-V
OUT
= 3V, 10 ≤I
OUT
≤800mA 0.2 0.5 %
LM1117I-3.3
V
IN
= 4.75V, 0 ≤I
OUT
≤800mA 1 15 mV
LM1117I-5.0
V
IN
= 6.5V, 0 ≤I
OUT
≤800mA 1 20 mV
V
IN
-V
OUT
Dropout Voltage
(Note 7)
I
OUT
= 100mA 1.10 1.30 V
I
OUT
= 500mA 1.15 1.35 V
I
OUT
= 800mA 1.20 1.40 V
I
LIMIT
Current Limit V
IN
-V
OUT
= 5V, T
J
= 25˚C 800 1200 1500 mA
Minimum Load
Current (Note 8)
LM1117I-ADJ
V
IN
= 15V 1.7 5mA
Quiescent Current LM1117I-3.3
V
IN
≤15V 5 15 mA
LM1117I-5.0
V
IN
≤15V 5 15 mA
Thermal Regulation T
A
= 25˚C, 30ms Pulse 0.01 0.1 %/W
Ripple Regulation f
RIPPLE
=1 20Hz, V
IN
-V
OUT
=3VV
RIPPLE
=1V
PP
60 75 dB
Adjust Pin Current 60 120 µA
Adjust Pin Current
Change
10 ≤I
OUT
≤800mA,
1.4V ≤V
IN
-V
OUT
≤10V 0.2 10 µA
Temperature Stability 0.5 %
Long Term Stability T
A
= 125˚C, 1000Hrs 0.3 %
RMS Output Noise (% of V
OUT
), 10Hz ≤f≤10kHz 0.003 %
Thermal Resistance
Junction-to-Case
3-Lead SOT-223 15.0 ˚C/W
3-Lead TO-252 10 ˚C/W
Thermal Resistance
Junction-to-Ambient
No air flow)
3-Lead SOT-223 (No heat sink) 136 ˚C/W
3-Lead TO-252 (No heat sink)(Note 9) 92 ˚C/W
8-Lead LLP(Note 10) 40 ˚C/W
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.
LM1117/LM1117I
www.national.com 6
Note 2: The maximum power dissipation is a function of TJ(max) ,θJA, and TA. The maximum allowable power dissipation at any ambient temperature is
PD=(T
J(max)–TA)/θJA. All numbers apply for packages soldered directly into a PC board.
Note 3: For testing purposes, ESD was applied using human body model, 1.5kΩin series with 100pF.
Note 4: Typical Values represent the most likely parametric norm.
Note 5: All limits are guaranteed by testing or statistical analysis.
Note 6: Load and line regulation are measured at constant junction room temperature.
Note 7: The dropout voltage is the input/output differential at which the circuit ceases to regulate against further reduction in input voltage. It is measured when the
output voltage has dropped 100mV from the nominal value obtained at VIN =V
OUT +1.5V.
Note 8: The minimum output current required to maintain regulation.
Note 9: Minimum pad size of 0.038in2
Note 10: Thermal Performance for the LLP was obtained using JESD51-7 board with six vias and an ambient temperature of 22˚C. For information about improved
thermal performance and power dissipation for the LLP, refer to Application Note AN-1187.
Typical Performance Characteristics
Dropout Voltage (V
IN
-V
OUT
) Short-Circuit Current
10091922 10091923
Load Regulation LM1117-ADJ Ripple Rejection
10091943 10091906
LM1117/LM1117I
www.national.com7
Typical Performance Characteristics (Continued)
LM1117-ADJ Ripple Rejection vs. Current Temperature Stability
10091907 10091925
Adjust Pin Current LM1117-2.85 Load Transient Response
10091926 10091908
LM1117-5.0 Load Transient Response LM1117-2.85 Line Transient Response
10091909 10091910
LM1117/LM1117I
www.national.com 8
Typical Performance Characteristics (Continued)
LM1117-5.0 Line Transient Response
10091911
Application Note
1.0 EXTERNAL CAPACITORS/STABILITY
1.1 Input Bypass Capacitor
An input capacitor is recommended. A 10µF tantalum on the
input is a suitable input bypassing for almost all applications.
1.2 Adjust Terminal Bypass Capacitor
The adjust terminal can be bypassed to ground with a by-
pass capacitor (C
ADJ
) to improve ripple rejection. This by-
pass capacitor prevents ripple from being amplified as the
output voltage is increased. At any ripple frequency, the
impedance of the C
ADJ
should be less than R1 to prevent the
ripple from being amplified:
1/(2π*f
RIPPLE
*C
ADJ
)<R1
The R1 is the resistor between the output and the adjust pin.
Its value is normally in the range of 100-200Ω. For example,
with R1 = 124Ωand f
RIPPLE
= 120Hz, the C
ADJ
should be >
11µF.
1.3 Output Capacitor
The output capacitor is critical in maintaining regulator sta-
bility, and must meet the required conditions for both mini-
mum amount of capacitance and ESR (Equivalent Series
Resistance). The minimum output capacitance required by
the LM1117 is 10µF, if a tantalum capacitor is used. Any
increase of the output capacitance will merely improve the
loop stability and transient response. The ESR of the output
capacitor should range between 0.3Ω-22Ω. In the case of
the adjustable regulator, when the C
ADJ
is used, a larger
output capacitance (22µf tantalum) is required.
2.0 OUTPUT VOLTAGE
The LM1117 adjustable version develops a 1.25V reference
voltage, V
REF
, between the output and the adjust terminal.
As shown in Figure 1, this voltage is applied across resistor
R1 to generate a constant current I1. The current I
ADJ
from
the adjust terminal could introduce error to the output. But
since it is very small (60µA) compared with the I1 and very
constant with line and load changes, the error can be ig-
nored. The constant current I1 then flows through the output
set resistor R2 and sets the output voltage to the desired
level.
For fixed voltage devices, R1 and R2 are integrated inside
the devices.
3.0 LOAD REGULATION
The LM1117 regulates the voltage that appears between its
output and ground pins, or between its output and adjust
pins. In some cases, line resistances can introduce errors to
the voltage across the load. To obtain the best load regula-
tion, a few precautions are needed.
Figure 2, shows a typical application using a fixed output
regulator. The Rt1 and Rt2 are the line resistances. It is
obvious that the V
LOAD
is less than the V
OUT
by the sum of
the voltage drops along the line resistances. In this case, the
load regulation seen at the R
LOAD
would be degraded from
the data sheet specification. To improve this, the load should
be tied directly to the output terminal on the positive side and
directly tied to the ground terminal on the negative side.
10091917
FIGURE 1. Basic Adjustable Regulator
LM1117/LM1117I
www.national.com9
Application Note (Continued)
When the adjustable regulator is used (Figure 3), the best
performance is obtained with the positive side of the resistor
R1 tied directly to the output terminal of the regulator rather
than near the load. This eliminates line drops from appearing
effectively in series with the reference and degrading regu-
lation. For example, a 5V regulator with 0.05Ωresistance
between the regulator and load will have a load regulation
due to line resistance of 0.05ΩxI
L
. If R1 (=125Ω) is con-
nected near the load, the effective line resistance will be
0.05Ω(1+R2/R1) or in this case, it is 4 times worse. In
addition, the ground side of the resistor R2 can be returned
near the ground of the load to provide remote ground sens-
ing and improve load regulation.
4.0 PROTECTION DIODES
Under normal operation, the LM1117 regulators do not need
any protection diode. With the adjustable device, the internal
resistance between the adjust and output terminals limits the
current. No diode is needed to divert the current around the
regulator even with capacitor on the adjust terminal. The
adjust pin can take a transient signal of ±25V with respect to
the output voltage without damaging the device.
When a output capacitor is connected to a regulator and the
input is shorted to ground, the output capacitor will discharge
into the output of the regulator. The discharge current de-
pends on the value of the capacitor, the output voltage of the
regulator, and rate of decrease of V
IN
. In the LM1117 regu-
lators, the internal diode between the output and input pins
can withstand microsecond surge currents of 10A to 20A.
With an extremely large output capacitor (≥1000 µF), and
with input instantaneously shorted to ground, the regulator
could be damaged.
In this case, an external diode is recommended between the
output and input pins to protect the regulator, as shown in
Figure 4.
5.0 HEATSINK REQUIREMENTS
When an integrated circuit operates with an appreciable
current, its junction temperature is elevated. It is important to
quantify its thermal limits in order to achieve acceptable
performance and reliability. This limit is determined by sum-
ming the individual parts consisting of a series of tempera-
ture rises from the semiconductor junction to the operating
environment. A one-dimensional steady-state model of con-
duction heat transfer is demonstrated in Figure 5. The heat
generated at the device junction flows through the die to the
die attach pad, through the lead frame to the surrounding
case material, to the printed circuit board, and eventually to
the ambient environment. Below is a list of variables that
may affect the thermal resistance and in turn the need for a
heatsink.
R
θ
JC (Component
Variables)
R
θ
CA (Application
Variables)
Leadframe Size & Material Mounting Pad Size,
Material, & Location
No. of Conduction Pins Placement of Mounting
Pad
Die Size PCB Size & Material
Die Attach Material Traces Length & Width
Molding Compound Size
and Material
Adjacent Heat Sources
Volume of Air
Ambient Temperatue
Shape of Mounting Pad
10091918
FIGURE 2. Typical Application using Fixed Output
Regulator
10091919
FIGURE 3. Best Load Regulation using Adjustable
Output Regulator
10091915
FIGURE 4. Regulator with Protection Diode
LM1117/LM1117I
www.national.com 10
Application Note (Continued)
The LM1117 regulators have internal thermal shutdown to
protect the device from over-heating. Under all possible
operating conditions, the junction temperature of the LM1117
must be within the range of 0˚C to 125˚C. A heatsink may be
required depending on the maximum power dissipation and
maximum ambient temperature of the application. To deter-
mine if a heatsink is needed, the power dissipated by the
regulator, P
D
, must be calculated:
I
IN
=I
L
+I
G
P
D
=(V
IN
-V
OUT
)I
L
+V
IN
I
G
Figure 6 shows the voltages and currents which are present
in the circuit.
The next parameter which must be calculated is the maxi-
mum allowable temperature rise, T
R
(max):
T
R
(max) = T
J
(max)-T
A
(max)
where T
J
(max) is the maximum allowable junction tempera-
ture (125˚C), and T
A
(max) is the maximum ambient tem-
perature which will be encountered in the application.
Using the calculated values for T
R
(max) and P
D
, the maxi-
mum allowable value for the junction-to-ambient thermal
resistance (θ
JA
) can be calculated:
θ
JA
=T
R
(max)/P
D
If the maximum allowable value for θ
JA
is found to be
≥136˚C/W for SOT-223 package or ≥79˚C/W for TO-220
package or ≥92˚C/W for TO-252 package, no heatsink is
needed since the package alone will dissipate enough heat
to satisfy these requirements. If the calculated value for θ
JA
falls below these limits, a heatsink is required.
As a design aid, Table 1 shows the value of the θ
JA
of
SOT-223 and TO-252 for different heatsink area. The copper
patterns that we used to measure these θ
JA
s are shown at
the end of the Application Notes Section. Figure 7 and Figure
8reflects the same test results as what are in the Table 1
Figure 9 and Figure 10 shows the maximum allowable power
dissipation vs. ambient temperature for the SOT-223 and
TO-252 device. Figures Figure 11 and Figure 12 shows the
maximum allowable power dissipation vs. copper area (in
2
)
for the SOT-223 and TO-252 devices. Please see AN1028
for power enhancement techniques to be used with SOT-223
and TO-252 packages.
*Application Note AN-1187 discusses improved thermal per-
formance and power dissipation for the LLP.
TABLE 1. θ
JA
Different Heatsink Area
Layout Copper Area Thermal Resistance
Top Side (in
2
)* Bottom Side (in
2
)(θ
JA
,˚C/W) SOT-223 (θ
JA
,˚C/W) TO-252
1 0.0123 0 136 103
2 0.066 0 123 87
3 0.3 0 84 60
4 0.53 0 75 54
5 0.76 0 69 52
61066 47
7 0 0.2 115 84
8 0 0.4 98 70
9 0 0.6 89 63
10 0 0.8 82 57
11 0 1 79 57
12 0.066 0.066 125 89
13 0.175 0.175 93 72
10091937
FIGURE 5. Cross-sectional view of Integrated Circuit
Mounted on a printed circuit board. Note that the case
temperature is measured at the point where the leads
contact with the mounting pad surface
10091916
FIGURE 6. Power Dissipation Diagram
LM1117/LM1117I
www.national.com11
Application Note (Continued)
TABLE 1. θ
JA
Different Heatsink Area (Continued)
Layout Copper Area Thermal Resistance
14 0.284 0.284 83 61
15 0.392 0.392 75 55
16 0.5 0.5 70 53
*Tab of device attached to topside copper
LM1117/LM1117I
www.national.com 12
Application Note (Continued)
10091913
FIGURE 7. θ
JA
vs. 1oz Copper Area for SOT-223
10091934
FIGURE 8. θ
JA
vs. 2oz Copper Area for TO-252
10091912
FIGURE 9. Maximum Allowable Power Dissipation vs.
Ambient Temperature for SOT-223
10091936
FIGURE 10. Maximum Allowable Power Dissipation vs.
Ambient Temperature for TO-252
10091914
FIGURE 11. Maximum Allowable Power Dissipation vs.
1oz Copper Area for SOT-223
10091935
FIGURE 12. Maximum Allowable Power Dissipation vs.
2oz Copper Area for TO-252
LM1117/LM1117I
www.national.com13
Application Note (Continued)
10091941
FIGURE 13. Top View of the Thermal Test Pattern in Actual Scale
LM1117/LM1117I
www.national.com 14
Application Note (Continued)
10091942
FIGURE 14. Bottom View of the Thermal Test Pattern in Actual Scale
LM1117/LM1117I
www.national.com15
Typical Application Circuits
10091930
Adjusting Output of Fixed Regulators
10091931
Regulator with Reference
10091929
1.25V to 10V Adjustable Regulator with Improved
Ripple Rejection
10091927
5V Logic Regulator with Electronic Shutdown*
LM1117/LM1117I
www.national.com 16
Typical Application Circuits (Continued)
10091932
Battery Backed-Up Regulated Supply
10091933
Low Dropout Negative Supply
LM1117/LM1117I
www.national.com17
Physical Dimensions inches (millimeters) unless otherwise noted
3-Lead SOT-223
NS Package Number MP04A
3-Lead TO-220
NS Package Number T03B
LM1117/LM1117I
www.national.com 18
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
3-Lead TO-263
NS Package Number TS3B
LM1117/LM1117I
www.national.com19
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
3-Lead TO-252
NS Package Number TD03B
8-Lead LLP
NS Package Number LDC08A
LM1117/LM1117I
www.national.com 20
Notes
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
For the most current product information visit us at www.national.com.
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WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL 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 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 to the user.
2. A critical component is 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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LM1117/LM1117I 800mA Low-Dropout Linear Regulator
