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LM317M
3-Terminal 0.5A Positive Adjustable Regulator
Features
•
•
•
•
•
•
Output Current in Excess of 0.5A
Output Adjustable Between 1.2V and 37V
Internal Thermal Overload Protection
Internal Short Circuit Current Limiting
Output Transistor Safe Area Compensation
Floating Operation for High Voltage Applications
Description
The LM317M is a 3-terminal adjustable positive voltage
regulator capable of supplying in excess of 500mA 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.
D-PAK
2
1 3
1. Adj 2. Output 3. Input
TO-220
12 3
Internal Block Diagram
V in
Input
3
+
-
V olta ge
Re fe re nce
P rote ction
Circ uitry
R lim it
2
1
V ad j
Vo
Output
Rev. 1.0.4
©2011 Fairchild Semiconductor Corporation
LM317M
Absolute Maximum Ratings
Parameter
Input-Output Voltage Differential
Power Dissipation
Thermal Resistance Junction-Case (TO-220)
Thermal Resistance Junction-Air (TO-220)
Thermal Resistance Junction-Air (D-PAK (Note1,2))
Operating Junction Temperature Range
Storage Temperature Range
Symbol
V
I
- V
O
P
D
R
θJC
R
θJA
R
θJA
T
j
T
STG
Value
40
Internally Limited
5
81
100
0 ~ +125
-65 ~ +125
Unit
V
W
°C/W
°C/W
°C/W
°C
°C
Electrical Characteristics
(V
I
-V
O
= 5V, I
O
= 0.1A, 0°C
≤
T
J
≤
+125°C, P
DMAX
= 7.5W, unless otherwise specified)
Parameter
Line Regulation (Note3)
Symbol
Rline
Conditions
T
A
= +25°C, 3V
≤
V
I
−V
O
≤
40V
3V
≤
V
I
−V
O
≤
40V
T
A
=+25°C, 10mA
≤
I
O
≤
0.5A
V
O
≤
5V
V
O
≥
5V
10mA
≤
I
O
≤
0.5A
V
O
≤
5V
V
O
≥
5V
I
ADJ
ΔI
ADJ
V
REF
ST
T
I
L(MIN)
V
I
- V
O
= 40V
V
I
- V
O
≤
15V, P
D
<
P
DMAX
Maximum Output Current
RMS Noise, % of V
OUT
Ripple Rejection
Long-Term Stability
I
O(MAX)
e
N
RR
ST
V
I
- V
O
= 40V
P
D
<
P
DMAX
, T
A
=+25°C
T
A
= +25°C, 10Hz
<
f
<
10kHz
V
O
= 10V, f = 120Hz
without C
ADJ
C
ADJ
= 10uF (Note4)
T
J
= +125°C, 1000Hours
-
3V
≤
V
I
- V
O
≤
40V
10mA
≤
I
O
≤
0.5A, P
D
<
P
DMAX
Min.
-
-
-
Typ.
0.01
0.02
5
0.1
20
0.3
50
0.2
1.25
0.7
3.5
0.9
0.25
0.003
65
80
0.3
Max.
0.04
0.07
25
0.5
70
1.5
100
5
1.30
-
10
-
-
-
-
1
A
%/V
O
dB
%/1000Hrs
mV
%/V
O
mV
%/V
O
uA
uA
V
%/V
O
mA
Unit
%/ V
Rload
Load Regulation (Note3)
-
-
-
Adjustment Pin Current
Adjustment Pin Current Change
Reference Voltage
Temperature Stability
Minimum Load Current to
Maintain Regulation
3V
<
V
I
- V
O
<
40V
1.20
10mA
≤
I
O
≤
0.5A, P
D
<
P
DMAX
-
-
-
0.5
0.15
-
66
-
Note:
1. Thermal resistance test board
Size: 76.2mm * 114.3mm * 1.6mm(1S0P)
JEDEC standard: JESD51-3, JESD51-7
2. Assume no ambient airflow.
3. Load and Line regulation are specified at constant junction temperature. Change in V
O
due to heating effects must be taken
into account separately. Pulse testing with low duty cycle is used.
4. C
ADJ
, when used, is connected between the adjustment pin and ground.
2
LM317M
Typical Performance Characteristics
Figure 1. Minimum Load Current
Figure 2. Peak Output Current vs. Input-Output
Differential Voltage
Figure 3. Adjustment Pin Current vs. Temperature
Figure 4. Ripple Rejection vs. Frequency
Figure 5. Load Regulation vs. Temperature
Figure 6. Line Regulation vs. Temperature
3
LM317M
Typical Performance Characteristics
(Continued)
Figure 7. Outputvoltage vs. Temperature
Figure 8. Thermal Shutdown
4
LM317M
Typical Application
D1
1N4002
V
O
Input
LM317M
+
120
V
ADJ
1K
720
KSP2222
MINIMUM V
O
= 1.25V
1.0uF
Output
TTL CONTROL
Figure 1. 1 5V Electronic Shutdown Regulator
D1 protects the device during an input short circuit.
LM317M
Input
240
50K
V
ADJ
KSP2907
R2
V
O
Output
1N4001
+
1.0uF
Figure 2. Slow Turn-On Regulator
I
O
Input
LM317M
V
O
R1
R2
Output
V
ADJ
I
ADJ
I
I
V
REF
1.25V
-
-
=
⎛
----------------
⎞
+
I
≅
---------------
OMAX
⎝
R1
⎠
ADJ
R1
V
REF
1.25V
-
-
=
⎛
---------------------
⎞
+
I
≅
---------------------
OMAX
⎝
R1
+
R2
⎠
ADJ R1
+
R2
5mA
<
I
O
<
500mA
Figure 3. Current Regulator
5
嵌入式系统
