LM117/LM317A/LM317 3-Terminal Adjustable Regulator
August 1999
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
voltage. 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 situ-
ated more than 6 inches from the input filter capacitors in
which case an input bypass is needed. An optional output
capacitor 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
“floating” and sees only the input-to-output differential volt-
age, supplies of several hundred volts can be regulated as
long as the maximum input to output differential is not ex-
ceeded, i.e., avoid short-circuiting the output.
Also, it makes an especially simple adjustable switching
regulator, 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. Sup-
plies with electronic shutdown can be achieved by clamping
the adjustment terminal to ground which programs the out-
put 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
negative complement, see LM137 series data sheet.
Features
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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
LM117 Series Packages
Part Number
Suffix
K
H
T
E
S
EMP
MDT
DS009063-1
Design
Package
TO-3
TO-39
TO-220
LCC
TO-263
SOT-223
TO-252
Load
Current
1.5A
0.5A
1.5A
0.5A
1.5A
1A
0.5A
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 1 µF to 1000 µF of aluminum or tantalum electrolytic are commonly
used to provide improved output impedance and rejection of transients.
SOT-223 vs D-Pak (TO-252)
Packages
DS009063-54
Scale 1:1
© 1999 National Semiconductor Corporation
DS009063
www.national.com
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
LM317A
LM317
−55˚C
≤
T
J
≤
+150˚C
−40˚C
≤
T
J
≤
+125˚C
0˚C
≤
T
J
≤
+125˚C
Preconditioning
Thermal Limit Burn-In
All Devices 100%
Electrical Characteristics
(Note 3)
Specifications with standard type face are for T
J
= 25˚C, and those with
boldface type
apply over
full Operating Tempera-
ture Range.
Unless otherwise specified, V
IN
− V
OUT
= 5V, and I
OUT
= 10 mA.
Parameter
Reference Voltage
3V
≤
(V
IN
− V
OUT
)
≤
40V,
10 mA
≤
I
OUT
≤
I
MAX
, P
≤
P
MAX
Line Regulation
Load Regulation
Thermal Regulation
Adjustment Pin Current
Adjustment Pin Current Change
Temperature Stability
Minimum Load Current
Current Limit
10 mA
≤
I
OUT
≤
I
MAX
3V
≤
(V
IN
− V
OUT
)
≤
40V
T
MIN
≤
T
J
≤
T
MAX
(V
IN
− V
OUT
) = 40V
(V
IN
− V
OUT
)
≤
15V
K Package
H Packages
(V
IN
− V
OUT
) = 40V
K Package
H Package
RMS Output Noise, % of V
OUT
Ripple Rejection Ratio
10 Hz
≤
f
≤
10 kHz
V
OUT
= 10V, f = 120 Hz,
C
ADJ
= 0 µF
V
OUT
= 10V, f = 120 Hz,
C
ADJ
= 10 µF
Long-Term Stability
Thermal Resistance,
Junction-to-Case
Thermal Resistance, Junction-
to-Ambient (No Heat Sink)
T
J
= 125˚C, 1000 hrs
K Package
H Package
E Package
K Package
H Package
E Package
35
140
66
1.5
0.5
0.3
0.15
2.2
0.8
0.4
0.2
0.003
65
80
0.3
2.3
12
1
3
15
3.4
1.8
A
A
A
A
%
dB
dB
%
˚C/W
˚C/W
˚C/W
˚C/W
˚C/W
˚C/W
1
3.5
5
%
mA
3V
≤
(V
IN
− V
OUT
)
≤
40V (Note 4)
10 mA
≤
I
OUT
≤
I
MAX
(Note 4)
20 ms Pulse
0.01
0.02
0.1
0.3
0.03
50
0.2
0.02
0.05
0.3
1
0.07
100
5
%/V
%/V
%
%
%/W
µA
µA
1.20
1.25
1.30
Conditions
Min
LM117
(Note 2)
Typ
Max
V
V
Units
www.national.com
2
Electrical Characteristics
(Note 3)
Specifications with standard type face are for T
J
= 25˚C, and those with
boldface type
apply over
full Operating Tempera-
ture Range.
Unless otherwise specified, V
IN
− V
OUT
= 5V, and I
OUT
= 10 mA.
Parameter
Reference Voltage
3V
≤
(V
IN
− V
OUT
)
≤
40V,
10 mA
≤
I
OUT
≤
I
MAX
, P
≤
P
MAX
Line Regulation
Load Regulation
Thermal Regulation
Adjustment Pin Current
Adjustment Pin Current
Change
Temperature Stability
Minimum Load Current
Current Limit
10 mA
≤
I
OUT
≤
I
MAX
3V
≤
(V
IN
− V
OUT
)
≤
40V
T
MIN
≤
T
J
≤
T
MAX
(V
IN
− V
OUT
) = 40V
(V
IN
− V
OUT
)
≤
15V
K, T, S Packages
H Package
MP Package
(V
IN
− V
OUT
) = 40V
K, T, S Packages
H Package
MP Package
RMS Output Noise, % of V
OUT
Ripple Rejection Ratio
10 Hz
≤
f
≤
10 kHz
V
OUT
= 10V, f = 120 Hz,
C
ADJ
= 0 µF
V
OUT
= 10V, f = 120 Hz,
C
ADJ
= 10 µF
Long-Term Stability
Thermal Resistance,
Junction-to-Case
T
J
= 125˚C, 1000 hrs
K Package
MDT Package
H Package
T Package
MP Package
Thermal Resistance,
Junction-to-Ambient (No Heat
Sink)
K Package
MDT Package(Note 6)
H Package
T Package
S Package (Note 6)
12
4
23.5
35
140
50
50
15
5
66
1.5
0.5
1.5
0.15
0.075
0.55
2.2
0.8
2.2
0.4
0.2
0.4
0.003
65
80
0.3
1
66
3.4
1.8
3.4
1.5
0.5
1.5
0.15
0.075
0.15
2.2
0.8
2.2
0.4
0.2
0.4
0.003
65
80
0.3
2.3
5
12
4
23.5
35
92
140
50
50
1
3
15
3.4
1.8
3.4
A
A
A
A
A
A
%
dB
dB
%
˚C/W
˚C/W
˚C/W
˚C/W
˚C/W
˚C/W
˚C/W
˚C/W
˚C/W
˚C/W
1
3.5
10
1
3.5
10
%
mA
3V
≤
(V
IN
− V
OUT
)
≤
40V (Note 4)
10 mA
≤
I
OUT
≤
I
MAX
(Note 4)
20 ms Pulse
0.005
0.01
0.1
0.3
0.04
50
0.2
0.01
0.02
0.5
1
0.07
100
5
0.01
0.02
0.1
0.3
0.04
50
0.2
0.04
0.07
0.5
1.5
0.07
100
5
%/V
%/V
%
%
%/W
µA
µA
Conditions
Min
1.238
1.225
LM317A
Typ
1.250
1.250
Max
1.262
1.270
1.20
1.25
1.30
Min
LM317
Typ
Max
V
V
Units
Note 1:
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is in-
tended 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:
Although power dissipation is internally limited, these specifications are applicable for maximum power dissipations of 2W for the TO-39 and SOT-223 and
20W for the TO-3, TO-220, and TO-263. I
MAX
is 1.5A for the TO-3, TO-220, and TO-263 packages, 0.5A for the TO-39 package and 1A for the SOT-223 Package.
All limits (i.e., the numbers in the Min. and Max. columns) are guaranteed to National’s AOQL (Average Outgoing Quality Level).
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:
If the TO-263 or TO-252 packages are used, the thermal resistance can be reduced by increasing the PC board copper area thermally connected to the
package. If the SOT-223 package is used, the thermal resistance can be reduced by increasing the PC board copper area (see applications hints for heatsinking).
3
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