©2001 Fairchild Semiconductor Corporation

www.fairchildsemi.com

Rev. 1.0.0

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

DescriptionThe LM337 is a 3-terminal negative adjustable regulator. Itsupplies in excess of 1.5A over an output voltage range of -1.2V to - 37V. This regulator requires only two externalresistor to set the output voltage. Included on the chip arecurrent limiting, thermal overload protection and safe areacompensation.

TO-220

1. Adj 2. Input 3. Output

1

Internal Block Diagram

1

VoltageReference

-

+

2

ProtectionCircuitry

3 Output

Input

Vadj

LM3373-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 detween the adjustment pin and ground.

Parameter Symbol Value UnitInput-Output Voltage Differential |VI - VO| 40 VPower Dissipation PD Internally limited WOperating Temperature Range TOPR 0 ~ +125 °CStorage Temperature Range TSTG -65 ~+125 °C

Parameter Symbol Conditions Min Typ. Max. Unit

Line Regulation (Note1) Rline

TA = +25°C3V ≤ I VI - VO I ≤ 40V - 0.01 0.04 %/ V3V ≤ I VI - VO I ≤ 40V - 0.02 0.07

Load Regulation (Note1) RloadTA = +25°C10mA ≤ IO ≤ 0.5A

- 15 50mV

10mA ≤ IO ≤ 1.5A - 15 150Adjustable Pin Current IADJ - - 50 100 µA

Adjustable Pin Current Change ∆IADJTA =+ 25°C10mA ≤ IO ≤ 1.5A3V ≤I VI - VO I ≤ 40V

- 2 5 µA

TA =+ 25°C -1.213 -1.250 -1.287Reference Voltage VREF 3V ≤ I VI - VO I ≤ 40V

10mA ≤ IO ≤ 1.5A -1.200 -1.250 -1.300 V

Temperature Stability STT 0°C ≤ ΤJ ≤ +125°C - 0.6 - %Minimum Load Current to Maintain Regulation IL(MIN)

3V ≤I VI - VO I ≤ 40V - 2.5 103V ≤I VI - VO I ≤ 10V - 1.5 6 mA

Output Noise eN TA =+25°C 10Hz ≤ f ≤10KHz - 0.003 - V/106

Ripple Rejection Ratio RRVO = -10V, f = 120Hz - 60 -CADJ = 10µF (Note2) 66 77 - dB

Long Term Stability ST TJ = 125°C ,1000Hours - 0.3 1 %Thermal Resistance Junction to Case RθJC - - 4 - °C/ W

LM337

3

Typical 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 aluminum electrolytic is recommended.

• VO= -1.25V (1+R2/R1)

-VI KA337

Ci0. 1µµµµF

VI VoVadj

R2

Iadj R1

IPROG

Co1µµµµF

-Vo

+ +

LM337

LM337

4

Mechanical DimensionsPackage

4.50 ±0.209.90 ±0.20

1.52 ±0.10

0.80 ±0.102.40 ±0.20

10.00 ±0.20

1.27 ±0.10

ø3.60 ±0.10

(8.70)

2.80

±0.

1015

.90

±0.2

0

10.0

8 ±0

.30

18.9

5MA

X.

(1.7

0)

(3.7

0)(3

.00)

(1.4

6)

(1.0

0)

(45°)

9.20

±0.

2013

.08

±0.2

0

1.30

±0.

10

1.30+0.10–0.05

0.50+0.10–0.05

2.54TYP[2.54 ±0.20]

2.54TYP[2.54 ±0.20]

TO-220