LM317CM & LM317CT
Vishay Semiconductor
Document Number 74809 www.vishay.com
29-Nov-01 1
New Product
3-Terminal Adjustable Output Positive Voltage Regulators
Description
The LM317 is an adjustable 3-terminal positive voltage
regulator capable of supplying in excess of 1.5A over an
output voltage range of 1.2V to 37V.This voltage regulator
is exceptionally easy to use and requires only two external
resistors to set the output voltage .Further , it emplo ys internal
current limiting, thermal shutdown and safe area compen-
sation, making it essentially blow-out proof.
Features
• Output current in excess of 1.5 ampere
• Output adjustable between 1.2V and 37V
• Internal ther mal overload protection
• Internal short-circuit current limiting
constant with temperature
• Output transistor safe-area compensation
• Floating operation for high voltage applications
• Eliminates stocking many fixed voltages
Mechanical Data
Case: TO-220 and TO-263 packages
Weight: approx. 1.35g
Case outlines are on the back page.
Pin Arrangement
1
1Output
Rlimit
Input
Vadj
3
2
Voltage
Reference Protection
Circuitry
+
--
Functional Block Diagram
Vin Vout
Cin
0.1µF
LM317
Co
1µF
IADJ Adjust R1
240Ω
R2
Maximum Ratings Ratings at 25°C ambient temperature unless otherwise specified.
Parameter Symbol Value Unit
Input-Output Voltage Diff erential Vi-Vo 40 Vdc
Power Dissipation, 25°C Free-Air Temperature PD 2W
Power Dissipation, 25°C Case Temperature PD 15 W
Operating Junction Temperature Range TJ0 to +125 °C
Storage Junction Temperature Range Tstg –65 to +150 °C
1. Adjust
2. Vout
3. Vin
Heatsink is connected to pin 2
Standard Application
Notes:
Cin is required if regulator is located an appreciable distance from power
supply filter.
Co is not needed for stability, however, it does improve transient response.
Vout = 1.25V (1 + R2/R1) + IAdj R2
Since IAdj is controlled to less than 100µA, the error associated with this
term is negligible in most applications
3
2
TO-220
(LM317CT)
TO-263
(LM317CM)
1
3
2
Part Number
Vishay Semiconductor
www.vishay.com Document Number 74809
229-Nov-01
Electrical Characteristics – LM317
V
i
-V
o
=5V, I
o
= 0.5A, T
J
= T
low to
T
high
(see Note 1), I
max
and P
max
per Note 2, unless otherwise noted.
Parameter Symbol Conditions Min. Typ. Max. Unit
Line Regulation (Fig. 1)(3) REGline TA= 25°C–0.01 0.04 %Vo/V
3.0V ≤VI– Vo≤40V TJ= 0°C thr u 125°C–0.02 0.07
Load Regulation (Fig. 2)(3) REGload Vo≤5.0 –525mV
TJ= 25°C, 10mA ≤Io≤1.5A Vo≥5.0 –0.1 0.5 %Vo
Load Regulation (Fig. 2)(3) REGload Vo≤5.0 –20 70 mV
10mA ≤Io≤1.5A Vo≥5.0 –0.3 1.5 %Vo
Thermal Regulation REG therm TJ= 25°C, 20ms Pulse –0.03 0.07 %Vo/W
Adjustment Pin Current (Fig. 3) IAdj –50 100 µA
Adjustment Pin Current Change ∆IAdj 10mA ≤IL≤1.5A –0.2 5 µA
2.5V ≤VI– Vo≤40V
Ref erence Voltage (Fig. 3)(4) Vref 10mA ≤Io≤1.5A 1.225 1.25 1.275 V
3V ≤VI– Vo≤40V
Temperature Stability (Fig. 3) TSTlow ≤TJ≤Thigh –1–%Vo
Min. Load Current to Maintain Regulation (Fig. 3) ILmin VI– Vo= 40V –3.5 10 mA
Maximum Output Current (Fig. 3) Imax VI– Vo≤15V 1.5 2.2 –A
VI– Vo= 40V, TJ= 25°C 0.15 0.4 –
RMS Noise, % of VoN
TJ= 25°C, 10HZ≤f ≤10KHZ
—0.003 –%Vo
Ripple Rejection (Fig. 4) RR Vo= 10V, f = 120HZ(5) —65 –dB
CAdj = 10µF6680–
Long-Ter m Stability (after 1000 hr) Fig. 3 STJ= 125°C(6), TJ= 25°C for –0.3 1.0 %
Endpoint Measurements
Thermal Resistance Junction to Case RθJC Tlow ≤TJ≤Thigh –5.0 –°C/W
Notes:
(1) Tlow = 0°C Thigh = 125°C
(2) Imax = 1.5A Pmax :TO-220 = 2W, TO-263 = 2W
(3) Load and line regulation are specified at constant junction temperature. Changes in Vodue to heating effects must be taken into account separately.
Pulse testing with low duty cycle is used.
(4) Selected devices with tightened tolerance reference voltage available.
(5) CAdj, when used, is connected between the addjustment pin and ground.
(6) Since Long-Term Stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability from lot to lot.
Part Number
Vishay Semiconductor
Document Number 74809 www.vishay.com
29-Nov-01 3
Vin
VIVout
Cin
0.1µF
Co
1µF
Adjust R1
R2
1%
240Ω
1%
LM317
RL
(min.
Load)
VOH (min. Load)
VOL (max. Load)
Pulse Testing Required:
1% Duty Cycle is Suggested
Vin Vout
Cin
0.1µF
Co
1µF
Adjust R1
R2
1%
240Ω
1%
LM317
RL
VIH
VIL VOH
VOL
Pulse Testing Required:
1% Duty Cycle is Suggested
Vin Vout
Cin
0.1µF
Co
1µF
Adjust R1
R2
1%
240
1%
RL
Pulse Testing Required:
1% Duty Cycle is Suggested
To Calculate R2:
Vo = ISET R2 + 1.250V
Assume ISET = 5.25mA
Fig. 3 – Standard Test Circuit
LM317 Vin Vout Vo = 10V
Cin
0.1µF
Co
1µF
Adjust R1
R2
1%
240
1%
RL
Fig. 4 – Ripple Rejection Test Circuit
LM317
CAdj
10µF
*D1 Discharges CADJ if
Output is Shorted to Ground
*D1
1N4002
24V
14V
f = 120HZ
IADJ
VI
IADJ
ISET
Vref
IL
VoVo
IL
IADJ
Fig. 2 – Load Regulation and
∆Iadj/Load Test Circuit
Fig. 1 – Line Regulation Test Circuit
Line Regulation (%/V) = x100
VOH -- VOL
VOL Load Regulator (mV) = Vo(min. Load) -- Vo(max. Load)
Load Regulator (%Vo) = x100
Vo(min. Load) -- Vo(max. Load)
Vo(min. Load)
Part Number
Vishay Semiconductor
www.vishay.com Document Number 74809
429-Nov-01
0
0.2
0.4
0.6
--75 --50 --25 0 25 50 75 100 125 150 175
Fig. 5 – Load Regulation
∆Vo -- Output Voltage Change (%)
--1.0
--0.8
--0.6
--0.4
--0.2
0
1
2
3
010203040
Fig. 6 – Current Limit
Io -- Output Current (A)
4
--75 --50 --25 0 25 50 75 100 125 150 175
Fig. 7 – Adjustment Pin Current
IADJ -- Adjustment Pin Current (µA)
35
40
45
50
55
60
65
70
75
--75 --50 --25 0 25 50 75 100 125 150 175
Fig. 9 – Temperature Stability
Vref -- Reference Voltage (V)
1.220
1.230
1.240
1.250
1.260
--75 --50 --25 0 25 50 75 100 125 150 175
Fig. 8 – Dropout Voltage
VI -- Vo -- Input -- Output Voltage
Differential (Vdc)
1.0
1.5
2.0
2.5
3.0
IL = 1.5A
IL = 1.0A
IL = 500mA
IL = 200mA
IL = 20mA
∆Vo = 100mV
0
0.2
0.4
0.6
--75 --50 --25 0 25 50 75 100 125 150 175
∆Vo -- Output Voltage Change (%)
--1.0
--0.8
--0.6
--0.4
--0.2
VI = 15V
Vo = 10V
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
4.0
4.5
01020304050
Fig. 10 – Minimum Operating Current
IO -- Quiescent Current (mA)
TJ = --55°C
TJ = 25°C
5.0
TJ = 150°C
IL = 0.5A
IL = 1.5A
TJ = 25°C
TJ = 150°CTJ = --55°C
Ratings and
Characteristic Curves(TA= 25°C unless otherwise noted)
Part Number
Vishay Semiconductor
Document Number 74809 www.vishay.com
29-Nov-01 5
20
40
60
80
100
510152025303540
Fig. 11 – Ripple Rejection
vs. Output Voltage
RR -- Ripple Rejection (db)
Vo -- Output Voltage (V)
010203040
∆VI -- Input Voltage ∆Vo -- Output Voltage
Change (V) Deviation (V)
t -- Time (µs)
0
0.5
1.0
0
0.5
1.0
1.5
--1.5
--1.0
--0.5
00
VI -- Vo = 5V
IL = 500mA
f = 120HZ
TJ = 25°C
CAdj = 10µF
Without CAdj
20
40
60
80
100
100 1K 100K10K 1M
Fig. 13 – Ripple Rejection
vs. Frequency
RR -- Ripple Rejection (db)
f -- Frequency (Hz)
010
IL = 500mA
VI = 15V
Vo = 10V
TJ = 25°C
CAdj = 10µF
Without CAdj
20
40
60
80
100
120
140
0.01 0.1 101
Fig. 12 – Ripple Rejection
vs. Output Current
RR -- Ripple Rejection (db)
Io -- Output Current (A)
0
VI = 15V
Vo = 10V
f = 120HZ
TJ = 25°C
CAdj = 10µF
Without CAdj
10--3
10--2
10--1
100
101
100 1K 100K10K 1M
Fig. 14 – Output Impedance
Output Impedance (Ω)
f -- Frequency (Hz)
10
VI = 15V
Vo = 10V
IL = 500mA
TJ = 25°C
Vo = 10V
IL = 50mA
TJ = 25°C
Without CAdj
CAdj = 10µF
CL = 1µF CAdj = 10µF
CL = 0
Without CAdj
VI
010203040
IL -- Load Vo -- Output Voltage
Current (A) Deviation (V)
t -- Time (µs)
0
0.5
1.0
1.5
0
1
2
3
--3
--2
--1
VI = 15V
Vo = 10V
INL = 50mA
TJ = 25°C
CL = 1µF CAdj = 10µF
CL = 0 Without CAdj
IL
Fig. 16 – Load Transient Response
Fig. 15 – Line Transient Response
Ratings and
Characteristic Curves(TA= 25°C unless otherwise noted)
Part Number
Vishay Semiconductor
www.vishay.com Document Number 74809
629-Nov-01
13.9 ± 0.41
2.53 ± 0.185
3.84 ± 0.6 Dia.
10.25 ± 0.25
28.7 ± 0.92
3.94 ± 0.375
2.69 ± 0.25
0.8 ± 0.12
1.3 ± 0.185
1.27 ± 0.12
2.55 ± 0.375
4.85 ± 0.375
0.387 ± 0.09
8.54 ± 0.26
6.26 ± 0.25
14.8 ± 0.51
TO-220 Case Outline
Dimensions in
millimeters
9.14
15.24
2.54 1.27
10.29 4.47
1.27
0.38
8° Max.
1.65
20°
2.54
Seating Plane
.10
TO-263 Case Outline
Dimensions in
millimeters
