LM317L
SEMICONDUCTOR
TECHNICAL DATA
LOW CURRENT
THREE–TERMINAL
ADJUSTABLE POSITIVE
VOLTAGE REGULATOR
ORDERING INFORMATION
Order this document by LM317L/D
Z SUFFIX
PLASTIC PACKAGE
CASE 29
Pin 1. Adjust
2. Vout
3. Vin
3
1
2
D SUFFIX
PLASTIC PACKAGE
CASE 751
(SOP–8*)
1
8
Pin 1. Vin
2. Vout
3. Vout
4. Adjust
5. N.C.
6. Vout
7. Vout
8. N.C.
* SOP–8 is an internally modified SO–8 pack-
age. Pins 2, 3, 6 and 7 are electrically common
to the die attach flag. This internal lead frame
modification decreases package thermal resis-
tance and increases power dissipation capabili-
ty when appropriately mounted on a printed cir-
cuit board. SOP–8 conforms to all external di-
mensions of the standard SO–8 package.
Operating
Temperature Range
Device
Package
LM317LD
LM317LZ
LM317LBZ
SOP–8
Plastic
Plastic
TJ = –40
°
to +125
°
C
TJ = 0
°
to +125
°
C
LM317LBD
SOP–8
LM317L
SEMICONDUCTOR
TECHNICAL DATA
LOW CURRENT
THREE–TERMINAL
ADJUSTABLE POSITIVE
VOLTAGE REGULATOR
ORDERING INFORMATION
Order this document by LM317L/D
Z SUFFIX
PLASTIC PACKAGE
CASE 29
Pin 1. Adjust
2. Vout
3. Vin
3
1
2
D SUFFIX
PLASTIC PACKAGE
CASE 751
(SOP–8*)
1
8
Pin 1. Vin
2. Vout
3. Vout
4. Adjust
5. N.C.
6. Vout
7. Vout
8. N.C.
* SOP–8 is an internally modified SO–8 pack-
age. Pins 2, 3, 6 and 7 are electrically common
to the die attach flag. This internal lead frame
modification decreases package thermal resis-
tance and increases power dissipation capabili-
ty when appropriately mounted on a printed cir-
cuit board. SOP–8 conforms to all external di-
mensions of the standard SO–8 package.
Operating
Temperature Range
Device
Package
LM317LD
LM317LZ
LM317LBZ
SOP–8
Plastic
Plastic
TJ = –40
°
to +125
°
C
TJ = 0
°
to +125
°
C
LM317LBD
SOP–8
1
MOTOROLA ANALOG IC DEVICE DATA
Three-Terminal Adjustable
Output Positive Voltage
Regulator
The LM317L is an adjustable 3–terminal positive voltage regulator
capable of supplying in excess of 100 mA over an output voltage range of
1.2 V to 37 V. This voltage regulator is exceptionally easy to use and
requires only two external resistors to set the output voltage. Further, it
employs internal current limiting, thermal shutdown and safe area
compensation, making them essentially blow–out proof.
The LM317L serves a wide variety of applications including local, on card
regulation. This device can also be used to make a programmable output
regulator, or by connecting a fixed resistor between the adjustment and
output, the LM317L can be used as a precision current regulator.
•
Output Current in Excess of 100 mA
•
Output Adjustable Between 1.2 V and 37 V
•
Internal Thermal Overload Protection
•
Internal Short Circuit Current Limiting
•
Output Transistor Safe–Area Compensation
•
Floating Operation for High Voltage Applications
•
Standard 3–Lead Transistor Package
•
Eliminates Stocking Many Fixed Voltages
Simplified Application
* 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.
Since IAdj is controlled to less than 100
µ
A, the error
associated with this term is negligible in most applications.
LM317L
Vin
Vout
R1
240
R2
Adjust
IAdj
Cin*
0.1
µ
F
+ CO**
1.0
µ
F
Vout
+
1.25 V 1
)
R2
R1
)
IAdj R2
©
Motorola, Inc. 1996
Rev 1
LM317L
2
MOTOROLA ANALOG IC DEVICE DATA
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Input–Output Voltage Differential
VI–VO
40
Vdc
Power Dissipation
PD
Internally Limited
W
Operating Junction Temperature Range
TJ
–40 to +125
°
C
Storage Temperature Range
Tstg
–65 to +150
°
C
ELECTRICAL CHARACTERISTICS
(VI–VO = 5.0 V; IO = 40 mA; TJ = Tlow to Thigh [Note 1]; Imax and Pmax [Note 2];
unless otherwise noted.)
LM317L, LB
Characteristics
Figure
Symbol
Min
Typ
Max
Unit
Line Regulation (Note 3)
TA = 25
°
C, 3.0 V
≤
VI – VO
≤
40 V
1
Regline
–
0.01
0.04
%/V
Load Regulation (Note 3), TA = 25
°
C
10 mA
≤
IO
≤
Imax – LM317L
VO
≤
5.0 V
VO
≥
5.0 V
2
Regload
–
–
5.0
0.1
25
0.5
mV
% VO
Adjustment Pin Current
3
IAdj
–
50
100
µ
A
Adjustment Pin Current Change
2.5 V
≤
VI – VO
≤
40 V, PD
≤
Pmax
10 mA
≤
IO
≤
Imax – LM317L
1, 2
∆
IAdj
–
0.2
5.0
µ
A
Reference Voltage
3.0 V
≤
VI – VO
≤
40 V, PD
≤
Pmax
10 mA
≤
IO
≤
Imax – LM317L
3
Vref
1.20
1.25
1.30
V
Line Regulation (Note 3)
3.0 V
≤
VI – VO
≤
40 V
1
Regline
–
0.02
0.07
%/V
Load Regulation (Note 3)
10 mA
≤
IO
≤
Imax – LM317L
VO
≤
5.0 V
VO
≥
5.0 V
2
Regload
–
–
20
0.3
70
1.5
mV
% VO
Temperature Stability (Tlow
≤
TJ
≤
Thigh)
3
TS
–
0.7
–
% VO
Minimum Load Current to Maintain Regulation (VI – VO = 40 V)
3
ILmin
–
3.5
10
mA
Maximum Output Current
VI – VO
≤
6.25 V, PD
≤
Pmax, Z Package
VI – VO
≤
40 V, PD
≤
Pmax, TA = 25
°
C, Z Package
3
Imax
100
–
200
20
–
–
mA
RMS Noise, % of VO
TA = 25
°
C, 10 Hz
≤
f
≤
10 kHz
N
–
0.003
–
% VO
Ripple Rejection (Note 4)
VO = 1.2 V, f = 120 Hz
CAdj = 10
µ
F, VO = 10.0 V
4
RR
60
–
80
80
–
–
dB
Long Term Stability, TJ = Thigh (Note 5)
TA = 25
°
C for Endpoint Measurements
3
S
–
0.3
1.0
%/1.0 k
Hrs.
Thermal Resistance, Junction–to–Case
Z Package
R
θ
JC
–
83
–
°
C/W
Thermal Resistance, Junction–to–Air
Z Package
R
θ
JA
–
160
–
°
C/W
NOTES: 1. Tlow to Thigh = 0
°
to +125
°
C for LM317L
–40
°
to +125
°
C for LM317LB
2. Imax = 100 mA
Pmax = 625 mW
3. Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be taken into account separately.
Pulse testing with low duty cycle is used.
4. CAdj, when used, is connected between the adjustment pin and ground.
5. 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.
LM317L
3
MOTOROLA ANALOG IC DEVICE DATA
Representative Schematic Diagram
18k
6.8V
6.8V
350
300
300
300
3.0k
30
0
70
200
k
2.5
60
5
0
130
8.67k
500
40
0
2.4k
12.8k
Vout
5.1k
6.3V
2.0k
6.0k
Adjust
Vin
180
180
10
pF
10
pF
* Pulse Testing Required:
1% Duty Cycle is suggested.
Line Regulation (%/V) =
VOH – VOL
x 100
*
VCC
VIH
VIL
Vin
Vout
VOH
VOL
RL
+
1
µ
F
CO
240
1%
R1
Adjust
R2
1
%
Cin
0.1
µ
F
LM317L
IAdj
Figure 1. Line Regulation and
∆
IAdj/Line Test Circuit
VOL
LM317L
4
MOTOROLA ANALOG IC DEVICE DATA
* Pulse Testing Required:
1% Duty Cycle is suggested.
Load Regulation (mV) = VO (min Load) –VO (max Load)
Load Regulation (% VO) =
VO (min Load) – VO (max Load)
X
100
VO (min Load)
VO (max Load)
LM317L
Cin
0.1
µ
F
Adjust
R2
1%
CO
1.0
µ
F
+
*
RL
(max Load)
RL
(min Load)
Vout
R1
240
1%
Vin*
Vin
IAdj
IL
Figure 2. Load Regulation and
∆
IAdj/Load Test Circuit
VO (min Load)
Pulse Testing Required:
1% Duty Cycle is suggested.
LM317L
Vin
Vout
Adjust
R1
240
1%
+
1
µ
F
CO
RL
Cin
R2
1%
To Calculate R2:
Vout = ISET R2 + 1.250 V
Assume ISET = 5.25 mA
IL
IAdj
ISET
Vref
VO
VI
0.1
µ
F
Figure 3. Standard Test Circuit
LM317L
Vin
Vout
Vout = 1.25 V
RL
Cin
0.1
µ
F
Adjust
R1
240
1%
D1 *
1N4002
CO
+
1
µ
F
14.30V
4.30V
R2
1.65K
1%
**
10
µ
F
+
* D1 Discharges CAdj if Output is Shorted to Ground.
f = 120 Hz
VO
**CAdj provides an AC ground to the adjust pin.
Figure 4. Ripple Rejection Test Circuit
LM317L
5
MOTOROLA ANALOG IC DEVICE DATA
I B
, QUIESCENT
CURRENT
(mA)
V
in
–V
out
, INPUT–OUTPUT
VOL
TAGE
DIFFERENTIAL
(V)
I O
, OUTPUT
CURRENT
(A)
Figure 5. Load Regulation
Figure 6. Ripple Rejection
Figure 7. Current Limit
Figure 8. Dropout Voltage
Figure 9. Minimum Operating Current
Figure 10. Ripple Rejection versus Frequency
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
–50
–25
0
25
50
75
100
125
150
∆
V
out
TJ, JUNCTION TEMPERATURE (
°
C)
, OUTPUT
VOL
TAGE CHANGE (%)
Vin = 45 V
Vout = 5.0 V
IL = 5.0 mA to 40 mA
Vin = 10 V
Vout = 5.0 V
IL = 5.0 mA to 100 mA
80
70
60
50
RR, RIPPLE REJECTION (dB)
–50
–25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (
°
C)
IL = 40 mA
f = 120 Hz
Vout = 10 V
Vin = 14 V to 24 V
–50
–25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (
°
C)
2.5
2.0
1.5
1.0
0.5
IL = 5.0 mA
IL = 100 mA
0.50
0.40
0.30
0.20
0.10
0
0
10
20
30
40
50
Vin–Vout, INPUT–OUTPUT VOLTAGE DIFFERENTIAL (V)
TJ = 25
°
C
TJ = 150
°
C
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
10
20
30
40
Vin–Vout, INPUT–OUTPUT VOLTAGE DIFFERENTIAL (V)
TJ = 55
°
C
TJ = 25
°
C
TJ = 150
°
C
100
90
80
70
60
50
40
30
20
10
10
100
1.0 k
10 k
100 k
1.0 M
f, FREQUENCY (Hz)
RR, RIPPLE REJECTION (dB)
IL = 40 mA
Vin = 5.0 V
±
1.0 VPP
Vout = 1.25 V
LM317L
6
MOTOROLA ANALOG IC DEVICE DATA
V
out
, OUTPUT
VOL
TAGE
∆
DEVIA
TION (V)
V
out
, OUTPUT
VOL
TAGE
∆
DEVIA
TION (V)
V
in
, INPUT
VOL
TAGE
∆
CHANGE (V)
NOISE VOL
TAGE
(
V
)
µ
V
out
, OUTPUT
VOL
TAGE CHANGE (%)
∆
I Adj
, ADJUSTMENT
PIN CURRENT
(
A
)
µ
CL = 0.3
µ
F; CAdj = 10
µ
F
Figure 11. Temperature Stability
Figure 12. Adjustment Pin Current
Figure 13. Line Regulation
Figure 14. Output Noise
Figure 15. Line Transient Response
Figure 16. Load Transient Response
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
1.0
0.5
0
0
10
20
30
40
t, TIME (
µ
s)
CL = 1
µ
F
CL = 0
Vin
Vout = 1.25 V
IL = 20 mA
TJ = 25
°
C
0.3
0.2
0.1
0
–0.1
–0.2
100
50
0
0
10
20
30
40
t, TIME (
µ
s)
I
CURRENT
(mA)
L
, LOAD
CL = 1
µ
F; CAdj = 10
µ
F
Vin = 15 V
Vout = 10 V
INL = 50 mA
TJ = 25
°
C
IL
–50
–25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (
°
C)
1.260
1.250
1.240
1.230
1.220
ref
V
, REFERENCE VOL
TAGE (V)
Vin = 4.2 V
Vout = Vref
IL = 5.0 mA
–50
–25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (
°
C)
80
70
65
60
55
50
45
40
35
Vin = 6.25 V
Vout = Vref
IL = 10 mA
IL = 100 mA
–50
–25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (
°
C)
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
Vin = 4.25 V to 41.25 V
Vout = Vref
IL = 5 mA
–50
–25
0
25
50
75
100
125
150
TJ, JUNCTION TEMPERATURE (
°
C)
10
8.0
6.0
4.0
Bandwidth 100 Hz to 10 kHz
–0.3
LM317L
7
MOTOROLA ANALOG IC DEVICE DATA
APPLICATIONS INFORMATION
Basic Circuit Operation
The LM317L is a 3–terminal floating regulator. In
operation, the LM317L develops and maintains a nominal
1.25 V reference (Vref) between its output and adjustment
terminals. This reference voltage is converted to a
programming current (IPROG) by R1 (see Figure 13), and this
constant current flows through R2 to ground. The regulated
output voltage is given by:
Vout = Vref (1 +
) + IAdj R2
R2
R1
Since the current from the adjustment terminal (IAdj)
represents an error term in the equation, the LM317L was
designed to control IAdj to less than 100
µ
A and keep it
constant. To do this, all quiescent operating current is
returned to the output terminal. This imposes the requirement
for a minimum load current. If the load current is less than this
minimum, the output voltage will rise.
Since the LM317L is a floating regulator, it is only the
voltage differential across the circuit which is important to
performance, and operation at high voltages with respect to
ground is possible.
+
Vref
Adjust
Vin
Vout
LM317L
R1
IPROG
Vout
R2
IAdj
Vref = 1.25 V Typical
Figure 17. Basic Circuit Configuration
Load Regulation
The LM317L is capable of providing extremely good load
regulation, but a few precautions are needed to obtain
maximum performance. For best performance, the
programming resistor (R1) should be connected as close to
the regulator as possible to minimize line drops which
effectively appear in series with the reference, thereby
degrading regulation. The ground end of R2 can be returned
near the load ground to provide remote ground sensing and
improve load regulation.
External Capacitors
A 0.1
µ
F disc or 1.0
µ
F tantalum input bypass capacitor
(Cin) is recommended to reduce the sensitivity to input line
impedance.
The adjustment terminal may be bypassed to ground to
improve ripple rejection. This capacitor (CAdj) prevents ripple
from being amplified as the output voltage is increased. A
10
µ
F capacitor should improve ripple rejection about 15 dB
at 120 Hz in a 10 V application.
Although the LM317L is stable with no output capacitance,
like any feedback circuit, certain values of external
capacitance can cause excessive ringing. An output
capacitance (CO) in the form of a 1.0
µ
F tantalum or 25
µ
F
aluminum electrolytic capacitor on the output swamps this
effect and insures stability.
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.
Figure 14 shows the LM317L with the recommended
protection diodes for output voltages in excess of 25 V or high
capacitance values (CO > 10
µ
F, CAdj > 5.0
µ
F). Diode D1
prevents CO from discharging thru the IC during an input
short circuit. Diode D2 protects against capacitor CAdj
discharging through the IC during an output short circuit. The
combination of diodes D1 and D2 prevents CAdj from
discharging through the IC during an input short circuit.
D1
Vin
Cin
1N4002
LM317L
Vout
R1
+
CO
D2
R2
CAdj
1N4002
Adjust
Figure 18. Voltage Regulator with
Protection Diodes
LM317L
8
MOTOROLA ANALOG IC DEVICE DATA
Figure 19. Adjustable Current Limiter
Figure 20. 5 V Electronic Shutdown Regulator
Figure 21. Slow Turn–On Regulator
Figure 22. Current Regulator
Vref
+25V
Vin
LM317L
Vout
R1
VO
1.25k
Adjust
IO
D2
1N914
1N5314
R2
500
* To provide current limiting of IO
to the system ground, the source of
the current limiting diode must be tied to
a negative voltage below – 7.25 V.
R2
≥
Vref
R1 =
VSS*
D1
1N914
VO < POV + 1.25 V + VSS
ILmin – IP < IO < 100 mA – IP
As shown O < IO < 95 mA
+
10
µ
F
Vin
Vout
240
1N4002
LM317L
Adjust
MPS2907
R2
50k
Vin
D1
1N4002
Vout
120
Adjust
720
+
1.0
µ
F
MPS2222
1.0k
TTL
Control
LM317L
Minimum Vout = 1.25 V
D1 protects the device during an input short circuit.
LM317L
Vin
R1
R2
Adjust
IAdj
Iout
Ioutmax =
Vref
+ IAdj
^
5.0 mA < Iout < 100 mA
Vout
1.25 V
Ioutmax =
Vref
+ IAdj
^
1.25 V
IDSS
IOmax + IDSS
R1