October 20, 2008
LM117/LM317A/LM317
3-Terminal Adjustable Regulator
General Description
The LM117 series of adjustable 3-terminal positive voltage
regulators is capable of supplying in excess of 1.5A over a
1.2V to 37V output range. They are exceptionally easy to use
and require only two external resistors to set the output volt-
age. Further, both line and load regulation are better than
standard fixed regulators. Also, the LM117 is packaged in
standard transistor packages which are easily mounted and
handled.
In addition to higher performance than fixed regulators, the
LM117 series offers full overload protection available only in
IC's. Included on the chip are current limit, thermal overload
protection and safe area protection. All overload protection
circuitry remains fully functional even if the adjustment termi-
nal is disconnected.
Normally, no capacitors are needed unless the device is sit-
uated more than 6 inches from the input filter capacitors in
which case an input bypass is needed. An optional output ca-
pacitor can be added to improve transient response. The
adjustment terminal can be bypassed to achieve very high
ripple rejection ratios which are difficult to achieve with stan-
dard 3-terminal regulators.
Besides replacing fixed regulators, the LM117 is useful in a
wide variety of other applications. Since the regulator is “float-
ing” and sees only the input-to-output differential voltage,
supplies of several hundred volts can be regulated as long as
the maximum input to output differential is not exceeded, i.e.,
avoid short-circuiting the output.
Also, it makes an especially simple adjustable switching reg-
ulator, a programmable output regulator, or by connecting a
fixed resistor between the adjustment pin and output, the
LM117 can be used as a precision current regulator. Supplies
with electronic shutdown can be achieved by clamping the
adjustment terminal to ground which programs the output to
1.2V where most loads draw little current.
For applications requiring greater output current, see LM150
series (3A) and LM138 series (5A) data sheets. For the neg-
ative complement, see LM137 series data sheet.
Features
Guaranteed 1% output voltage tolerance (LM317A)
Guaranteed max. 0.01%/V line regulation (LM317A)
Guaranteed max. 0.3% load regulation (LM117)
Guaranteed 1.5A output current
Adjustable output down to 1.2V
Current limit constant with temperature
P+ Product Enhancement tested
80 dB ripple rejection
Output is short-circuit protected
Typical Applications
1.2V–25V Adjustable Regulator
906301
Full output current not available at high input-output voltages
*Needed if device is more than 6 inches from filter capacitors.
Optional—improves transient response. Output capacitors in the range
of 1μF to 1000μF of aluminum or tantalum electrolytic are commonly used
to provide improved output impedance and rejection of transients.
LM117/LM317A/LM317 Package Options
Part
Number Suffix Package Output
Current
LM117, LM317 K TO-3 1.5A
LM317A, LM317 T TO-220 1.5A
LM317 S TO-263 1.5A
LM317A, LM317 EMP SOT-223 1.0A
LM117, LM317A, LM317 H TO-39 0.5A
LM117 E LCC 0.5A
LM317A, LM317 MDT TO-252 0.5A
SOT-223 vs. TO-252 (D-Pak)
Packages
906354
Scale 1:1
© 2008 National Semiconductor Corporation 9063 www.national.com
LM117/LM317A/LM317 3-Terminal Adjustable Regulator
Connection Diagrams
TO-3 (K)
Metal Can Package
906330
CASE IS OUTPUT
Bottom View
Steel Package
NS Package Number K02A or K02C
TO-39 (H)
Metal Can Package
906331
CASE IS OUTPUT
Bottom View
NS Package Number H03A
TO-263 (S)
Surface-Mount Package
906335
Top View
TO-220 (T)
Plastic Package
906332
Front View
NS Package Number T03B
TO-263 (S)
Surface-Mount Package
906336
Side View
NS Package Number TS3B
Ceramic Leadless
Chip Carrier (E)
906334
Top View
NS Package Number E20A
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LM117/LM317A/LM317
4-Lead SOT-223 (EMP)
906359
Front View
NS Package Number MP04A
TO-252 (MDT)
906366
Front View
NS Package Number TD03B
Ordering Information
Package Temperature
Range
Output
Current
Order
Number
Package
Marking
Transport
Media
NSC
Drawing
TO-3
Metal Can
(K)
−55°C TJ +150°C 1.5A LM117K STEEL LM117K STEEL P+ 50 Per Bag K02A
0°C TJ +125°C 1.5A LM317K STEEL LM317K STEEL P+ 50 Per Bag
−55°C TJ +150°C 1.5A LM117K/883 LM117K/883 50 Per Bag K02C
TO-220
3- Lead
−40°C TJ +125°C 1.5A LM317AT LM317AT P+ 45 Units/Rail T03B
0°C TJ +125°C 1.5A LM317T LM317T P+ 45 Units/Rail
TO-263
3- Lead 0°C TJ +125°C 1.5A LM317S LM317S P+ 45 Units/Rail TS3B
LM317SX 500 Units Tape and Reel
SOT-223
4- Lead
0°C TJ +125°C 1.0A LM317EMP N01A 1k Units Tape and Reel
MP04A
LM317EMPX 2k Units Tape and Reel
−40°C TJ +125°C 1.0A LM317AEMP N07A 1k Units Tape and Reel
LM317AEMPX 2k Units Tape and Reel
TO-39
Metal Can
(H)
−55°C TJ +150°C 0.5A LM117H LM117H P+ 500 Per Box
H03A
−55°C TJ +150°C 0.5A LM117H/883 LM117H/883 20 Per Tray
−40°C TJ +125°C 0.5A LM317AH LM317AH P+ 500 Per Box
0°C TJ +125°C 0.5A LM317H LM317H P+ 500 Per Box
LCC −55°C TJ +150°C 0.5A LM117E/883 LM117E/883 50 Units/Rail E20A
TO-252
3- Lead
D-Pack
0°C TJ +125°C 0.5A LM317MDT LM317MDT 75 Units/Rail
TD03B
LM317MDTX 2.5k Units Tape and Reel
−40°C TJ +125°C 0.5A LM317AMDT LM317AMDT 75 Units/Rail
LM317AMDTX 2.5k Units Tape and Reel
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LM117/LM317A/LM317
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Power Dissipation Internally Limited
Input-Output Voltage Differential +40V, −0.3V
Storage Temperature −65°C to +150°C
Lead Temperature
Metal Package (Soldering, 10 seconds) 300°C
Plastic Package (Soldering, 4 seconds) 260°C
ESD Tolerance (Note 5) 3 kV
Operating Temperature Range
LM117 −55°C TJ +150°C
LM317A −40°C TJ +125°C
LM317 0°C TJ +125°C
Preconditioning
Thermal Limit Burn-In All Devices 100%
LM117 Electrical Characteristics (Note 3)
Specifications with standard type face are for TJ = 25°C, and those with boldface type apply over full Operating Temperature
Range. Unless otherwise specified, VIN − VOUT = 5V, and IOUT = 10 mA.
Parameter Conditions LM117 (Note 2)
Min Typ Max Units
Reference Voltage 3V (VIN − VOUT) 40V,
10 mA IOUT IMAX
1.20 1.25 1.30 V
Line Regulation 3V (VIN − VOUT) 40V (Note 4) 0.01
0.02
0.02
0.05 %/V
Load Regulation 10 mA IOUT IMAX (Note 4) 0.1
0.3
0.3
1%
Thermal Regulation 20 ms Pulse 0.03 0.07 %/W
Adjustment Pin Current 50 100 μA
Adjustment Pin Current Change 10 mA IOUT IMAX
3V (VIN − VOUT) 40V 0.2 5 μA
Temperature Stability TMIN TJ TMAX 1 %
Minimum Load Current (VIN − VOUT) = 40V 3.5 5 mA
Current Limit
(VIN − VOUT) 15V
K Package
H, E Package
1.5
0.5
2.2
0.8
3.4
1.8 A
(VIN − VOUT) = 40V
K Package
H, E Package
0.3
0.15
0.4
0.20 A
RMS Output Noise, % of VOUT 10 Hz f 10 kHz 0.003 %
Ripple Rejection Ratio VOUT = 10V, f = 120 Hz, CADJ = 0 μF 65 dB
VOUT = 10V, f = 120 Hz, CADJ = 10 μF66 80 dB
Long-Term Stability TJ = 125°C, 1000 hrs 0.3 1 %
Thermal Resistance, θJC
Junction-to-Case
K (TO-3) Package
H (TO-39) Package
E (LCC) Package
2
21
12
°C/W
Thermal Resistance, θJA
Junction-to-Ambient
(No Heat Sink)
K (TO-3) Package
H (TO-39) Package
E (LCC) Package
39
186
88
°C/W
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LM117/LM317A/LM317
LM317A and LM317 Electrical Characteristics (Note 3)
Specifications with standard type face are for TJ = 25°C, and those with boldface type apply over full Operating Temperature
Range. Unless otherwise specified, VIN − VOUT = 5V, and IOUT = 10 mA.
Parameter Conditions LM317A LM317
Min Typ Max Min Typ Max Units
Reference Voltage
1.238 1.250 1.262 - 1.25 - V
3V (VIN − VOUT) 40V,
10 mA IOUT IMAX
1.225 1.250 1.270 1.20 1.25 1.30 V
Line Regulation 3V (VIN − VOUT) 40V (Note 4) 0.005
0.01
0.01
0.02 0.01
0.02
0.04
0.07 %/V
Load Regulation 10 mA IOUT IMAX (Note 4) 0.1
0.3
0.5
1 0.1
0.3
0.5
1.5 %
Thermal Regulation 20 ms Pulse 0.04 0.07 0.04 0.07 %/W
Adjustment Pin Current 50 100 50 100 μA
Adjustment Pin Current Change 10 mA IOUT IMAX
3V (VIN − VOUT) 40V 0.2 5 0.2 5 μA
Temperature Stability TMIN TJ TMAX 1 1 %
Minimum Load Current (VIN − VOUT) = 40V 3.5 10 3.5 10 mA
Current Limit
(VIN − VOUT) 15V
K, T, S Packages
EMP Package
H, MDT Packages
-
1.5
0.5
-
2.2
0.8
-
3.4
1.8
1.5
1.5
0.5
2.2
2.2
0.8
3.4
3.4
1.8
A
(VIN − VOUT) = 40V
K, T, S Packages
EMP Package
H, MDT Packages
-
0.112
0.075
-
0.30
0.20
0.15
0.112
0.075
0.40
0.30
0.20
A
RMS Output Noise, % of VOUT 10 Hz f 10 kHz 0.003 0.003 %
Ripple Rejection Ratio VOUT = 10V, f = 120 Hz, CADJ = 0 μF 65 65 dB
VOUT = 10V, f = 120 Hz, CADJ = 10 μF66 80 66 80 dB
Long-Term Stability TJ = 125°C, 1000 hrs 0.3 1 0.3 1 %
Thermal Resistance, θJC
Junction-to-Case
K (TO-3) Package
T (TO-220) Package
S (TO-263) Package
EMP (SOT-223) Package
H (TO-39) Package
MDT (TO-252) Package
-
-
-
23.5
21
12
2
4
4
23.5
21
12
°C/W
Thermal Resistance, θJA
Junction-to-Ambient
(No Heat Sink)
K (TO-3) Package
T (TO-220) Package
S (TO-263) Package (Note 6)
EMP (SOT-223) Package (Note 6)
H (TO-39) Package
MDT (TO-252) Package (Note 6)
-
-
-
140
186
103
39
50
50
140
186
103
°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 do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.
The guaranteed specifications apply only for the test conditions listed.
Note 2: Refer to RETS117H drawing for the LM117H, or the RETS117K for the LM117K military specifications.
Note 3: IMAX = 1.5A for the K (TO-3), T (TO-220), and S (TO-263) packages. IMAX = 1.0A for the EMP (SOT-223) package. IMAX = 0.5A for the H (TO-39), MDT
(TO-252), and E (LCC) packages. Device power dissipation (PD) is limited by ambient temperature (TA), device maximum junction temperature (TJ), and package
thermal resistance (θJA). The maximum allowable power dissipation at any temperature is : PD(MAX) = ((TJ(MAX) - TA)/θJA). All Min. and Max. limits are guaranteed
to National's Average Outgoing Quality Level (AOQL).
Note 4: Regulation is measured at a constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects
are covered under the specifications for thermal regulation.
Note 5: Human body model, 100 pF discharged through a 1.5 kΩ resistor.
Note 6: When surface mount packages are used (TO-263, SOT-223, TO-252), the junction to ambient thermal resistance can be reduced by increasing the PC
board copper area that is thermally connected to the package. See the Applications Hints section for heatsink techniques.
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LM117/LM317A/LM317
Typical Performance Characteristics Output Capacitor = 0 μF unless otherwise noted
Load Regulation
906337
Current Limit
906338
Adjustment Current
906339
Dropout Voltage
906340
VOUT vs VIN, VOUT = VREF
906367
VOUT vs VIN, VOUT = 5V
906368
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LM117/LM317A/LM317
Temperature Stability
906341
Minimum Operating Current
906342
Ripple Rejection
906343
Ripple Rejection
906344
Ripple Rejection
906345
Output Impedance
906346
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LM117/LM317A/LM317
Line Transient Response
906347
Load Transient Response
906348
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LM117/LM317A/LM317
Application Hints
In operation, the LM117 develops a nominal 1.25V reference
voltage, VREF, between the output and adjustment terminal.
The reference voltage is impressed across program resistor
R1 and, since the voltage is constant, a constant current I1
then flows through the output set resistor R2, giving an output
voltage of
(1)
906305
FIGURE 1.
Since the 100μA current from the adjustment terminal repre-
sents an error term, the LM117 was designed to minimize
IADJ and make it very constant with line and load changes. To
do this, all quiescent operating current is returned to the out-
put establishing a minimum load current requirement. If there
is insufficient load on the output, the output will rise.
EXTERNAL CAPACITORS
An input bypass capacitor is recommended. A 0.1μF disc or
1μF solid tantalum on the input is suitable input bypassing for
almost all applications. The device is more sensitive to the
absence of input bypassing when adjustment or output ca-
pacitors are used but the above values will eliminate the
possibility of problems.
The adjustment terminal can be bypassed to ground on the
LM117 to improve ripple rejection. This bypass capacitor pre-
vents ripple from being amplified as the output voltage is
increased. With a 10 μF bypass capacitor 80dB ripple rejec-
tion is obtainable at any output level. Increases over 10 μF do
not appreciably improve the ripple rejection at frequencies
above 120Hz. If the bypass capacitor is used, it is sometimes
necessary to include protection diodes to prevent the capac-
itor from discharging through internal low current paths and
damaging the device.
In general, the best type of capacitors to use is solid tantalum.
Solid tantalum capacitors have low impedance even at high
frequencies. Depending upon capacitor construction, it takes
about 25 μF in aluminum electrolytic to equal 1μF solid tan-
talum at high frequencies. Ceramic capacitors are also good
at high frequencies; but some types have a large decrease in
capacitance at frequencies around 0.5 MHz. For this reason,
0.01 μF disc may seem to work better than a 0.1 μF disc as
a bypass.
Although the LM117 is stable with no output capacitors, like
any feedback circuit, certain values of external capacitance
can cause excessive ringing. This occurs with values be-
tween 500 pF and 5000 pF. A 1 μF solid tantalum (or 25 μF
aluminum electrolytic) on the output swamps this effect and
insures stability. Any increase of the load capacitance larger
than 10 μF will merely improve the loop stability and output
impedance.
LOAD REGULATION
The LM117 is capable of providing extremely good load reg-
ulation but a few precautions are needed to obtain maximum
performance. The current set resistor connected between the
adjustment terminal and the output terminal (usually 240Ω)
should be tied directly to the output (case) of the regulator
rather than near the load. This eliminates line drops from ap-
pearing effectively in series with the reference and degrading
regulation. For example, a 15V regulator with 0.05Ω resis-
tance between the regulator and load will have a load regu-
lation due to line resistance of 0.05Ω × IL. If the set resistor is
connected near the load the effective line resistance will be
0.05Ω (1 + R2/R1) or in this case, 11.5 times worse.
Figure 2 shows the effect of resistance between the regulator
and 240Ω set resistor.
906306
FIGURE 2. Regulator with Line Resistance in Output Lead
With the TO-3 package, it is easy to minimize the resistance
from the case to the set resistor, by using two separate leads
to the case. However, with the TO-39 package, care should
be taken to minimize the wire length of the output lead. The
ground of R2 can be returned near the ground of the load to
provide remote ground sensing and improve load regulation.
PROTECTION DIODES
When external capacitors are used with any IC regulator it is
sometimes necessary to add protection diodes to prevent the
capacitors from discharging through low current points into
the regulator. Most 10 μF capacitors have low enough internal
series resistance to deliver 20A spikes when shorted. Al-
though the surge is short, there is enough energy to damage
parts of the IC.
When an output capacitor is connected to a regulator and the
input is shorted, the output capacitor will discharge into the
output of the regulator. The discharge current depends on the
value of the capacitor, the output voltage of the regulator, and
the rate of decrease of VIN. In the LM117, this discharge path
is through a large junction that is able to sustain 15A surge
with no problem. This is not true of other types of positive
regulators. For output capacitors of 25 μF or less, there is no
need to use diodes.
The bypass capacitor on the adjustment terminal can dis-
charge through a low current junction. Discharge occurs when
either the input, or the output, is shorted. Internal to the LM117
is a 50Ω resistor which limits the peak discharge current. No
protection is needed for output voltages of 25V or less and 10
μF capacitance. Figure 3 shows an LM117 with protection
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LM117/LM317A/LM317
diodes included for use with outputs greater than 25V and
high values of output capacitance.
906307
(2)
D1 protects against C1
D2 protects against C2
FIGURE 3. Regulator with Protection Diodes
HEATSINK REQUIREMENTS
The LM317 regulators have internal thermal shutdown to pro-
tect the device from over-heating. Under all operating condi-
tions, the junction temperature of the LM317 should not
exceed the rated maximum junction temperature (TJ) of 150°
C for the LM117, or 125°C for the LM317A and LM317. A
heatsink may be required depending on the maximum device
power dissipation and the maximum ambient temperature of
the application. To determine if a heatsink is needed, the
power dissipated by the regulator, PD, must be calculated:
PD = ((VIN − VOUT) × IL) + (VIN × IG) (3)
Figure 4 shows the voltage and currents which are present in
the circuit.
The next parameter which must be calculated is the maximum
allowable temperature rise, TR(MAX):
TR(MAX) = TJ(MAX) − TA(MAX) (4)
where TJ(MAX) is the maximum allowable junction temperature
(150°C for the LM117, or 125°C for the LM317A/LM317), and
TA(MAX) is the maximum ambient temperature which will be
encountered in the application.
Using the calculated values for TR(MAX) and PD, the maximum
allowable value for the junction-to-ambient thermal resistance
(θJA) can be calculated:
θJA = (TR(MAX) / PD) (5)
906360
FIGURE 4. Power Dissipation Diagram
If the calculated maximum allowable thermal resistance is
higher than the actual package rating, then no additional work
is needed. If the calculated maximum allowable thermal re-
sistance is lower than the actual package rating either the
power dissipation (PD) needs to be reduced, the maximum
ambient temperature TA(MAX) needs to be reduced, the ther-
mal resistance (θJA) must be lowered by adding a heatsink,
or some combination of these.
If a heatsink is needed, the value can be calculated from the
formula:
θHA JA - (θCH + θJC)) (6)
where (θCH is the thermal resistance of the contact area be-
tween the device case and the heatsink surface, and θJC is
thermal resistance from the junction of the die to surface of
the package case.
When a value for θ(H−A) is found using the equation shown, a
heatsink must be selected that has a value that is less than,
or equal to, this number.
The θ(H−A) rating is specified numerically by the heatsink man-
ufacturer in the catalog, or shown in a curve that plots tem-
perature rise vs power dissipation for the heatsink.
HEATSINKING SURFACE MOUNT PACKAGES
The TO-263 (S), SOT-223 (EMP) and TO-252 (MDT) pack-
ages use a copper plane on the PCB and the PCB itself as a
heatsink. To optimize the heat sinking ability of the plane and
PCB, solder the tab of the package to the plane.
HEATSINKING THE SOT-223 PACKAGE
Figure 5 and Figure 6 show the information for the SOT-223
package. Figure 6 assumes a θ(J−A) of 74°C/W for 1 ounce
copper and 51°C/W for 2 ounce copper and a maximum junc-
tion temperature of 125°C. Please see AN-1028 for thermal
enhancement techniques to be used with SOT-223 and
TO-252 packages.
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LM117/LM317A/LM317
906357
FIGURE 5. θ(J−A) vs Copper (2 ounce) Area for the
SOT-223 Package
906358
FIGURE 6. Maximum Power Dissipation vs TAMB for the
SOT-223 Package
HEATSINKING THE TO-263 PACKAGE
Figure 7 shows for the TO-263 the measured values of θ(J
−A) for different copper area sizes using a typical PCB with 1
ounce copper and no solder mask over the copper area used
for heatsinking.
As shown in Figure 7, increasing the copper area beyond 1
square inch produces very little improvement. It should also
be observed that the minimum value of θ(J−A) for the TO-263
package mounted to a PCB is 32°C/W.
906355
FIGURE 7. θ(J−A) vs Copper (1 ounce) Area for the TO-263
Package
As a design aid, Figure 8 shows the maximum allowable pow-
er dissipation compared to ambient temperature for the
TO-263 device (assuming θ(J−A) is 35°C/W and the maximum
junction temperature is 125°C).
906356
FIGURE 8. Maximum Power Dissipation vs TAMB for the
TO-263 Package
HEATSINKING THE TO-252 PACKAGE
If the maximum allowable value for θJA is found to be 103°
C/W (Typical Rated Value) 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 θJA
falls below these limits, a heatsink is required.
As a design aid, Table 1 shows the value of the θJA of TO-252
for different heatsink area. The copper patterns that we used
to measure these θJAs are shown at the end of the Application
Notes Section. Figure 9 reflects the same test results as what
are in Table 1.
Figure 10 shows the maximum allowable power dissipation
vs. ambient temperature for the TO-252 device. Figure 11
shows the maximum allowable power dissipation vs. copper
area (in2) for the TO-252 device. Please see AN-1028 for
thermal enhancement techniques to be used with SOT-223
and TO-252 packages.
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LM117/LM317A/LM317
TABLE 1. θJA Different Heatsink Area
Layout Copper Area Thermal Resistance
Top Side (in2)* Bottom Side (in2)(θJA°C/W) TO-252
1 0.0123 0 103
2 0.066 0 87
3 0.3 0 60
4 0.53 0 54
5 0.76 0 52
6 1.0 0 47
7 0.066 0.2 84
8 0.066 0.4 70
9 0.066 0.6 63
10 0.066 0.8 57
11 0.066 1.0 57
12 0.066 0.066 89
13 0.175 0.175 72
14 0.284 0.284 61
15 0.392 0.392 55
16 0.5 0.5 53
Note: * Tab of device attached to topside of copper.
906361
FIGURE 9. θJA vs 2oz Copper Area for TO-252
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LM117/LM317A/LM317
906363
FIGURE 10. Maximum Allowable Power Dissipation vs. Ambient Temperature for TO-252
906362
FIGURE 11. Maximum Allowable Power Dissipation vs. 2oz Copper Area for TO-252
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LM117/LM317A/LM317
906364
FIGURE 12. Top View of the Thermal Test Pattern in Actual Scale
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LM117/LM317A/LM317
906365
FIGURE 13. Bottom View of the Thermal Test Pattern in Actual Scale
Schematic Diagram
906308
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LM117/LM317A/LM317
Typical Applications
5V Logic Regulator with Electronic Shutdown*
906303
*Min. output 1.2V
Slow Turn-On 15V Regulator
906309
Adjustable Regulator with Improved Ripple Rejection
906310
†Solid tantalum
*Discharges C1 if output is shorted to ground
High Stability 10V Regulator
906311
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LM117/LM317A/LM317
High Current Adjustable Regulator
906312
‡Optional—improves ripple rejection
†Solid tantalum
*Minimum load current = 30 mA
0 to 30V Regulator
906313
Full output current not available at high input-output voltages
Power Follower
906314
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LM117/LM317A/LM317
5A Constant Voltage/Constant Current Regulator
906315
†Solid tantalum
*Lights in constant current mode
1A Current Regulator
906316
1.2V–20V Regulator with Minimum Program Current
906317
*Minimum load current 4 mA
High Gain Amplifier
906318
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LM117/LM317A/LM317
Low Cost 3A Switching Regulator
906319
†Solid tantalum
*Core—Arnold A-254168-2 60 turns
4A Switching Regulator with Overload Protection
906320
†Solid tantalum
*Core—Arnold A-254168-2 60 turns
Precision Current Limiter
906321
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LM117/LM317A/LM317
Tracking Preregulator
906322
Current Limited Voltage Regulator
906323
(Compared to LM117's higher current limit)
—At 50 mA output only ¾ volt of drop occurs in R3 and R4
Adjusting Multiple On-Card Regulators with Single Control*
906324
*All outputs within ±100 mV
†Minimum load—10 mA
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LM117/LM317A/LM317