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LM337
3-Terminal 1.5A Negative Adjustable Regulator
Features
• Output current in excess of 1.5A
• Output voltage 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
• Standard 3-pin TO-220 package
Internal Block Diagram
Description
The LM337 is a 3-terminal negative adjustable regulator. It
supplies in excess of 1.5A over an output voltage range of
-1.2V to - 37V. This regulator requires only two external
resistor to set the output voltage. Included on the chip are
current limiting, thermal overload protection and safe area
compensation.
TO-220
1
1. Adj 2. Input 3. Output
Vadj
1
Voltage
Reference
©2001 Fairchild Semiconductor Corporation
3
Output
-
+
Protection
Circuitry
Input
2
Rev. 1.0.0
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LM337
Absolute Maximum Ratings
Parameter Symbol Value Unit
Input-Output Voltage Differential |V
Power Dissipation P
Operating Temperature Range T
Storage Temperature Range T
- VO|40 V
I
D
OPR
STG
Internally limited W
0 ~ +125 °C
-65 ~+125 °C
Electrical Characteristics
≤ T
(VI - VO = 5V, IO = 40mA, 0°C
Parameter Symbol Conditions Min Typ. Max. Unit
Line Regulation (Note1) R
Load Regulation (Note1) R
Adjustable Pin Current I
Adjustable Pin Current Change ∆I
Reference Voltage V
Temperature Stability ST
Minimum Load Current to Maintain
Regulation
Output Noise e
Ripple Rejection Ratio RR
Long Term Stability ST T
Thermal Resistance Junction to
Case
≤ +125°C, P
J
load
ADJ
REF
I
L(MIN)
R
θJC
line
ADJ
T
N
= 20W, unless otherwise specified)
DMAX
TA = +25°C
3V ≤
V
I
- VO I ≤ 40V
I
- 0.01 0.04
3V ≤ I VI - VO I ≤ 40V - 0.02 0.07
TA = +25°C
10mA ≤ I
10mA ≤ I
O
O
≤ 0.5A
≤ 1.5A - 15 150
-1550
- - 50 100 µA
TA =+ 25°C
10mA ≤ I
3V ≤I V
=+ 25°C -1.213 -1.250 -1.287
T
A
≤ 1.5A
O
- VO I ≤ 40V
I
3V ≤ I VI - VO I ≤ 40V
10mA ≤ I
≤ 1.5A
O
-25µA
-1.200 -1.250 -1.300 V
0°C ≤ ΤJ ≤ +125°C - 0.6 - %
3V ≤I VI - VO I ≤ 40V - 2.5 10
3V ≤I V
- VO I ≤ 10V - 1.5 6 mA
I
TA =+25°C 10Hz ≤ f ≤10KHz - 0.003 - V/10
V
= -10V, f = 120Hz - 60 -
O
C
= 10µF (Note2) 66 77 - dB
ADJ
= 125°C ,1000Hours - 0.3 1 %
J
--4-°C/ W
%/ V
mV
6
Note:
1. Load and line regulation are specified at constant junction temperature. Change in V
account separately. Pulse testing with low duty is used.
2. C
, when used, is connected detween the adjustment pin and ground.
ADJ
2
O due to heating effects
must be taken into
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Typical Application
I
PROG
R
I
adj
Vadj
KA337
LM337
2
R
1
+
Ci
0. 1
F
µµµµ
-V
I
VI Vo
Figure 1. Programmable Regulator
• Ci is required if regulator is located more then 4 inch es from power supply filter.
A 1.0µF solid tantalum or 10µF aluminum electrolytic is recommended.
Co is necessary for stability. A 1.0µF solid tantalum or 10µF aluminum electrolytic
•VO= -1.25V (1+R2/R1)
+
Co
F
1
µµµµ
-V
o
is recommended.
LM337
3
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LM337
Mechanical Dimensions
Package
9.90
±0.20
(8.70)
(1.70)
±0.20
9.20
±0.10
1.30
(1.46)
ø3.60
±0.10
TO-220
±0.10
2.80
(3.70)(3.00)
±0.20
15.90
(45°)
18.95MAX.
4.50
1.30
±0.20
+0.10
–0.05
±0.20
13.08
[2.54
(1.00)
1.27
±0.10
2.54TYP
±0.20
]
10.00
±0.20
1.52
±0.10
0.80
±0.10
2.54TYP
[2.54
±0.20
±0.30
10.08
+0.10
0.50
–0.05
2.40
±0.20
]
4
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Ordering Information
Product Number Package Operating Temperature
LM337T TO-220 0°C to + 125°C
LM337
5
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LM337
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURT HER NOTICE TO ANY
PRODUCTS HEREI N TO IMPROVE RELIABILITY, FUNCTIO N OR DESIGN. FAIRCH IL D DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER IT S PATENT RIGHTS, NOR THE RIGHTS OF OTHE RS.
LIFE SUPPORT POL I CY
FAIRCHILD’S PR ODUCTS ARE NOT AUTH ORIZED FOR USE AS C RITICAL COMPONENT S IN LIFE SUPPORT DE VICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein :
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
2. A critical component in any component of a life support
device or sy stem whose fai lure to perform can be
reasonably expec ted to cause the failur e of the life support
device or system, or to affect its safety or effec t iv ene ss .
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
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2001 Fairchild Semiconductor Corporation
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