LM317
3-TERMINAL ADJUSTABLE REGULATOR
SLVS044H SEPTEMBER 1997 REVISED DECEMBER 2001
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
D
Output Voltage Range Adjustable From
1.2 V to 37 V
D
Output Current Greater Than 1.5 A
D
Internal Short-Circuit Current Limiting
D
Thermal Overload Protection
D
Output Safe-Area Compensation
D
Package Options Include Plastic
Small-Outline Transistor SOT-223 (DCY),
Flange Mounted (KTE) and Heat-Sink
Mounted (KC) Packages
description
The LM317 is an adjustable three-terminal
positive-voltage regulator capable of supplying
more than 1.5 A over an output-voltage range of
1.2 V to 37 V. It is exceptionally easy to use and
requires only two external resistors to set the
output voltage. Furthermore, both line and load
regulation are better than standard fixed
regulators. The LM317 is packaged in the KC
(TO-220AB) and KTE packages, which are easy
to handle and use.
In addition to having higher performance than
fixed regulators, this device includes on-chip
current limiting, thermal overload protection, and
safe-operating-area protection. All overload
protection remains fully functional, even if the
ADJUST terminal is disconnected.
The LM317 is versatile in its applications,
including uses in programmable output regulation
and local on-card regulation. Or, by connecting a
fixed resistor between the ADJUST and OUTPUT
terminals, the LM317 can function as a precision
current regulator. An optional output capacitor can
be added to improve transient response. The
ADJUST terminal can be bypassed to achieve
very high ripple-rejection ratios, which are difficult
to achieve with standard three-terminal
regulators.
The LM317 is characterized for operation over the
virtual junction temperature range of 0
C to
125
C.
The OUTPUT terminal is in electrical
contact with the mounting base.
TO-220AB
INPUT
OUTPUT
ADJUST
KC PACKAGE
(TOP VIEW)
KTE PACKAGE
(TOP VIEW)
INPUT
OUTPUT
ADJUST
The OUTPUT terminal is in electrical
contact with the mounting base.
I
O
A
I O
A
DCY PACKAGE
(TOP VIEW)
INPUT
OUTPUT
ADJUST
Copyright
2001, Texas Instruments Incorporated
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
LM317
3-TERMINAL ADJUSTABLE REGULATOR
SLVS044H SEPTEMBER 1997 REVISED DECEMBER 2001
2
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
AVAILABLE OPTIONS
PACKAGED DEVICES
TJ
HEAT-SINK
(DCY)
HEAT-SINK
MOUNTED, TO-220
(KC)
PLASTIC FLANGE
MOUNTED, POWER FLEX
(KTE)
0
C to 125
C
LM317DCY
LM317KC
LM317KTER
The DCY package also is available taped and reeled, e.g., LM317DCYR.
The KTE package has the same footprint as TO-263 and can be mounted on a TO-263
land pattern. The KTE package is only available taped and reeled.
schematic diagram
ADJUST
OUTPUT
INPUT
absolute maximum ratings over virtual junction temperature range (unless otherwise noted)
Input-to-output differential voltage, V
I
V
O
40
V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Package thermal impedance,
JA
(see Notes 1 and 2): DCY package
49
C/W
. . . . . . . . . . . . . . . . . . . . . . . . .
(see Notes 1 and 3): KC package
25
C/W
. . . . . . . . . . . . . . . . . . . . . . . . . . .
(see Notes 1 and 2): KTE package
23
C/W
. . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds
260
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
stg
65
C to 150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTES:
1. Maximum power dissipation is a function of TJ(max),
JA, and TA. The maximum allowable power dissipation at any allowable
ambient temperature is PD = (TJ(max) TA)/
JA. Operating at the absolute maximum TJ of 150
C can affect reliability.
2. The package thermal impedance is calculated in accordance with JESD 51-5.
3. The package thermal impedance is calculated in accordance with JESD 51-7.
recommended operating conditions
MIN
MAX
UNIT
VI VO
Input-to-output voltage differential
3
37
V
IO
Output current
1.5
A
TJ
Operating virtual junction temperature
0
125
C
LM317
3-TERMINAL ADJUSTABLE REGULATOR
SLVS044H SEPTEMBER 1997 REVISED DECEMBER 2001
3
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
electrical characteristics over recommended ranges of operating virtual junction temperature
(unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Input voltage (line) regulation
VI VO = 3 V to 40 V
TJ = 25
C
0.01
0.04
%/V
Input voltage (line) regulation
VI VO = 3 V to 40 V
TJ = 0
C to 125
C
0.02
0.07
%/V
CADJ = 10
F,
VO
5 V
25
mV
Output voltage
IO = 10 mA to 1500 mA
ADJ
,
TJ = 25
C
VO
5 V
0.1
0.5
%VO
g
(load) regulation
IO = 10 mA to 1500 mA
TJ = 0
C to 125
C
VO
5 V
20
70
mV
TJ = 0
C to 125
C
VO
5 V
0.3
1.5
%VO
Thermal regulation
20-ms pulse,
TJ = 25
C
0.03
0.07
%VO/W
ADJUST terminal current
50
100
A
Change in
ADJUST terminal current
VI VO = 2.5 V to 40 V, PD
20 W, IO = 10 mA to 1500 mA
0.2
5
A
Reference voltage (Vref)
(OUTPUT to ADJUST)
VI VO = 3 V to 40 V, PD
20 W, IO = 10 mA to 1500 mA
1.2
1.25
1.3
V
Output-voltage
temperature stability
TJ = 0
C to 125
C
0.7
%VO
Minimum load current
to maintain regulation
VI VO = 40 V
3.5
10
mA
Peak output current
VI VO
15 V,
PD
<
PMAX (see Note 1)
1.5
2.2
A
Peak output current
VI VO
40 V, PD
<
PMAX (see Note 1), TJ = 25
C
0.15
0.4
A
Output noise voltage (RMS)
f = 10 H
Z
to 10 kH
Z
,
TJ = 25
C
0.003
%VO
Ripple rejection
VO = 10 V
f = 120 H
Z
CADJ = 0
F
57
dB
Ripple rejection
VO = 10 V,
f = 120 H
Z
CADJ = 10
F
62
64
dB
Long-term stability
TJ = 25
C
0.3
1
%/1k Hrs
Unless otherwise noted, the following test conditions apply: |VI VO| = 5 V and IOMAX = 1.5 A, TJ = 0
C to 125
C. Pulse testing techniques are
used to maintain the junction temperature as close to the ambient temperature as possible.
Input regulation is expressed here as the percentage change in output voltage per 1-V change at the input.
CADJ is connected between the ADJUST terminal and GND.
NOTE 4: Maximum power dissipation is a function of TJ(max),
JA, and TA. The maximum allowable power dissipation at any allowable ambient
temperature is PD = (TJ(max) TA)/
JA. Operating at the absolute maximum TJ of 150
C can affect reliability.
LM317
3-TERMINAL ADJUSTABLE REGULATOR
SLVS044H SEPTEMBER 1997 REVISED DECEMBER 2001
4
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
R1
240
IAdj
R2
Cin (Note A)
0.1
F
CO (Note B)
1.0
F
VI
VO
NOTES: A. Cin is not required if the regulator is close enough to the power-supply filter.
B. CO improves transient response, but is not needed for stability.
Since IAdj is typically 50
A, it is negligible in most applications.
Vref = 1.25 V
V
out
+
V
ref
1
)
R2
R1
) (
I
Adj
R2
)
Vout is calculated as:
INPUT
OUTPUT
ADJUST
LM317
Figure 1. Adjustable Voltage Regulator
C1
0.1
F
R1
120
R2
3 k
INPUT
OUTPUT
ADJUST
LM317
VO
+35 V
R3
680
10 V
Since IAdj is typically 50
A, it is negligible in most applications.
V
out
+
V
ref
1
)
R2
)
R3
R1
)
I
Adj
(
R2
)
R3
)
10 V
Vout is calculated as:
Figure 2. 0-V to 30-V Regulator Circuit
LM317
3-TERMINAL ADJUSTABLE REGULATOR
SLVS044H SEPTEMBER 1997 REVISED DECEMBER 2001
5
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
C1
0.1
F
C3
1
F
R1
240
INPUT
OUTPUT
ADJUST
LM317
VO
VI
D1
1N4002
(see Note A)
R2
5 k
C2
10
F
NOTE A: D1 discharges C2 if the output is shorted to ground.
Figure 3. Adjustable Regulator Circuit With Improved Ripple Rejection
ADJUST
OUTPUT
INPUT
VI
R1
LM317
I
limit
+
1.2
R1
Figure 4. Precision Current-Limiter Circuit
C1
0.1
F
C2
1
F
R1
240
INPUT
OUTPUT
ADJUST
LM317
VI
INPUT
OUTPUT
ADJUST
VO
LM317
R2
720
R3
120
R4
1 k
Output
Adjust
Figure 5. Tracking Preregulator Circuit
LM317
3-TERMINAL ADJUSTABLE REGULATOR
SLVS044H SEPTEMBER 1997 REVISED DECEMBER 2001
6
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
R1
1.2 k
R2
20 k
INPUT
OUTPUT
ADJUST
LM317
VO
VI
Figure 6. 1.2-V to 20-V Regulator Circuit With Minimum Program Current
INPUT
OUTPUT
ADJUST
LM317
VO
VI
INPUT
OUTPUT
ADJUST
LM317
VO
VI
INPUT
OUTPUT
ADJUST
LM317
VO
VI
R1
120
R2
1 k
Minimum load current from each output is 10 mA. All output voltages are within 200 mV of each other.
Figure 7. Adjusting Multiple On-Card Regulators With a Single Control
R1
240
R2
2.4 k
INPUT
OUTPUT
ADJUST
LM317
VI
RS
0.2
(see Note A)
NOTE A: RS controls the output impedance of the charger.
The use of RS allows for low charging rates with a fully charged battery.
Z
OUT
+
R
S
1
)
R2
R1
Figure 8. Battery-Charger Circuit
LM317
3-TERMINAL ADJUSTABLE REGULATOR
SLVS044H SEPTEMBER 1997 REVISED DECEMBER 2001
7
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
INPUT
OUTPUT
ADJUST
LM317
VI
24
Figure 9. 50-mA Constant-Current Battery-Charger Circuit
R1
240
INPUT
OUTPUT
ADJUST
LM317
VO = 15 V
VI
D1
1N4002
R2
2.7 k
C1
25
F
R3
50 k
2N2905
Figure 10. Slow Turn-On 15-V Regulator Circuit
480
120
INPUT
OUTPUT
ADJUST
LM317
VI
120
480
INPUT
OUTPUT
ADJUST
LM317
VI
12 VI(PP)
6 VO(PP)
2 W (TYP)
Figure 11. AC Voltage-Regulator Circuit
LM317
3-TERMINAL ADJUSTABLE REGULATOR
SLVS044H SEPTEMBER 1997 REVISED DECEMBER 2001
8
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
R1
240
R2
1.1 k
INPUT
OUTPUT
ADJUST
LM317
VI+
R3
(see Note A)
VI
NOTE A: R3 sets the peak current (0.6 A for a 1-
resistor).
Figure 12. Current-Limited 6-V Charger Circuit
INPUT
OUTPUT
ADJUST
LM317
VI
2N2905
INPUT
OUTPUT
ADJUST
LM317
INPUT
OUTPUT
ADJUST
LM317
TL080
0.2
0.2
0.2
100
5 k
5 k
150
1.5 k
200 pF
4.5 V to 25 V
_
+
Figure 13. Adjustable 4-A Regulator Circuit
LM317
3-TERMINAL ADJUSTABLE REGULATOR
SLVS044H SEPTEMBER 1997 REVISED DECEMBER 2001
9
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
INPUT
OUTPUT
ADJUST
LM317
2N2905
22
VI
5 k
500
120
1N4002
See
Note A
10
F
(see Note B)
47
F
10
F
TIP73
VO
NOTES: A. The minimum load current is 30 mA.
B. This optional capacitor improves ripple rejection.
Figure 14. High-Current Adjustable Regulator Circuit
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Copyright
2001, Texas Instruments Incorporated
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