©2009 Fairchild Semiconductor Corporation
www.fairchildsemi.com
Rev. 1.0.1
Features
• Output Current in Excess of 1.5A
• Output Voltage Adjustable Between -1.2V and -37V
• Internal Thermal Overload Protection
• Internal Short Circui t Current Limiting
• Output Transistor Safe Area Compensation
• Floating Operation for High Voltage Applications
• Standard 3-Pin TO-220 Package
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. Adj 2. Input 3. Output
1
Internal Block Diagram
1
Voltage
Reference -
+
2
Protection
Circuitry
3Output
Input
Vadj
LM337
3-Terminal 1.5A Negative Adjustable Regulator
LM337
2
Absolute Maximum Ratings
Electrical Characteristics
(VI - VO = 5V, IO = 40mA, 0°C ≤ TJ ≤ +125°C, PDMAX = 20W, unless otherwise specified)
Note:
1. Load and line regulation are specified at constant junction temperature. Change in VO due to heating effects must be taken into
account separately. Pulse testing with low duty is used.
2. CADJ, when used, is connected between the adjustment pin and ground.
Parameter Symbol Value Unit
Input-Output Voltage Differential |VI - VO|40 V
Power Dissipation PDInternally limited W
Operating Temperature Range TOPR 0 ~ +125 °C
Storage Temperature Range TSTG -65 ~ +125 °C
Parameter Symbol Conditions Min. Typ. Max. Unit
Line Regulation (Note1) Rline TA = +25°C
3V ≤ I VI - VO I ≤ 40V -0.010.04
%/ V
3V ≤ I VI - VO I ≤ 40V - 0.02 0.07
Load Regulation (Note1) Rload TA = +25°C
10mA ≤ IO ≤ 0.5A -1550
mV
10mA ≤ IO ≤ 1.5A - 15 150
Adjustable Pin Current IADJ --50100μA
Adjustable Pin Current Change ΔIADJ
TA = +25°C, 10mA ≤ IO ≤ 1.5A
3V ≤I VI - VO I ≤ 40V -25
μA
TA = +25°C -1.213 -1.250 -1.287
Reference Volt ag e VREF 3V ≤ I VI - VO I ≤ 40V
10mA ≤ IO ≤ 1.5A -1.200 -1.250 -1.300 V
Temperature Stability STT0°C ≤ ΤJ ≤ +125°C - 0.6 - %
Minimum Load Current to Maintain
Regulation IL(MIN) 3V ≤I VI - VO I ≤ 40V - 2.5 10 mA
3V ≤I VI - VO I ≤ 10V - 1.5 6
Output Noise eNTA = +25°C 10Hz ≤ f ≤10kHz - 0.003 - V/106
Ripple Rejection Ratio RR VO = -10V, f = 120Hz - 60 - dB
CADJ = 10μF (Note2) 66 77 -
Long Term Stability ST TJ = 125°C ,1000Hours - 0.3 1 %
Thermal Resistance Junction to
Case RθJC --4-°C/W
LM337
3
Ty pical Application
Figure 1. Programmable Regulator
• Ci is required if regulator is located more then 4 inches 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 alumin um electrolytic is recommended.
•V
O= -1.25V (1+R2/R1)
-VI KA337
Ci
0. 1μF
VI Vo
Vadj
R2
Iadj R1
IPROG
Co
1μF
-Vo
++
LM337
LM337
4
Mechanical Dimensions
Package Dimensions in millimeters
TO-220 [SINGLE GAUGE]
LM337
5
Ordering Information
Product Number Package Operating Temperature
LM337T TO-220 0°C to +125°C
LM337
7/3/09 0.0m 001
Stock#DS400296
© 2009 Fairchild Semiconductor Corporation
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