LM 317.pdf

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LM317

3-Terminal Positive Adjustable Regulator

Features

•

Description

This monolithic integrated circuit is an adjustable 3-terminal

positive voltage regulator designed to supply more than 1.5A

of load current with an output voltage adjustable over a

1.2V to 37V. It employs internal current limiting, thermal

shut-down and safe area co mpensation.

Output Current In Excess of 1.5A

•

Output Adjustable Between 1.2V and 37V

•

Internal Thermal Overload Protection

•

Internal Short Circuit Current Limiting

•

Output Transistor Safe Operating Area Compensation

•

TO-220 Package

TO-220 (Single Gauge)

Output

1. Adj 2. Output 3. Input

Internal Block Diagram

Vin

Input

Protection

Circuitry

Voltage

Reference

Rlimit

Output

Adj

Vadj

Rev. 1.0.6

LM317

Absolute Maximum Ratings

Parameter

Symbol

Value

Unit

Input-Output Voltage Differential

V I - V O

Lead Temperature

T LEAD

230

° C

Power Dissipation

P D

Internally limited

Operating Junction Temperature Range

T j

0 ~ +125

° C

Storage Temperature Range

T STG

-65 ~ +125

° C

Temperature Coefficient of Output Voltage

Δ Vo/ Δ T

±0.02

%/ ° C

Note 1: Absolute Maximum Ratings: are those values beyond which the safety of the device cannot be guaranteed. The device

should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed

at the absolute maximum ratings. The "Recommended Operating Conditions" table will define the conditions for actual device

operation.

Electrical Characteristics

(VI-VO = 5V, IO = 0.5A, 0 ° C ≤ TJ ≤ +125 ° C, IMAX = 1.5A, PDMAX = 20W, unless otherwise specified)

Parameter

Symbol

Conditions

Min.

Typ.

Max.

Unit

TA = +25 ° C

3V ≤ V I - V O ≤ 40V

0.01

0.04

%/ V

Line Regulation (Note2)

Rline

3V ≤ V I - V O ≤ 40V

0.02

0.07

%/ V

T A = +25 ° C, 10mA ≤ I O ≤ I MAX

V O < 5V

V O ≥ 5V

0.4

0.5

%/V O

Load Regulation (Note2)

Rload

10mA ≤ I O ≤ I MAX

V O < 5V

V O ≥ 5V

0.8

1.5

%/V O

Adjustable Pin Current

I ADJ

100

μ A

3V ≤ V I - V O ≤ 40V

10mA ≤ I O ≤ I MAX P D ≤ P MAX

Adjustable Pin Current Change

Δ I ADJ

2.0

μ A

3V ≤ V IN - V O ≤ 40V

10mA ≤ IO ≤ IMAX

P D ≤ P MAX

Reference Voltage

VREF

1.20

1.25

1.30

Temperature Stability

ST T

0.7

%/V O

Minimum Load Current to Maintain

Regulation

I L(MIN)

V I - V O = 40V

3.5

V I - V O ≤ 15V, P D ≤ P MAX

V I - V O ≤ 40V, P D ≤ P MAX

T A =25 ° C

1.5

2.2

0.3

Maximum Output Current

I O(MAX)

RMS Noise, % of V OUT

e N

T A = +25 ° C, 10Hz ≤ f ≤ 10kHz

0.003

0.01

%/V O

V O = 10V, f = 120Hz

without C ADJ

C ADJ = 10 μ F (Note3)

Ripple Rejection

T A = +25 ° C for end point

measurements, 1000HR

Long-Term Stability, T J = T HIGH

0.3

Thermal Resistance Junction to Case

R θ JC

° C/W

Note 2: Load and line regulation are specified at constant junction temperature. Change in V D due to heating effects must be

taken into account separately. Pulse testing with low duty is used. (P MAX = 20W)

Note 3: C ADJ , when used, is connected between the adjustment pin and ground.

LM317

Typical Performance Characteristics

TEMPERATURE (° C)

Figure 1. Load Regulation

Figure 2. Adjustment Current

TEMPERATURE (° C)

Figure 3. Dropout Voltage

Figure 4. Reference Voltage

LM317

Typical Application

LM317

KA317

V I

Output

Input

Vadj

R 1

0. 1 μ F

1 μ F

I adj

R 2

V O = 1.25V (1+ R 2 / R 1 )+I adj R 2

Figure 5. Programmable Regulator

•Ci is required when regulator is located an appreciable distance from power supply filter.

C o is not needed for stability, however, it does improve transient response.

Since I ADJ is controlled to less than 100μA, the error associated with this term is negligible in most applications.

LM317

Mechanical Dimensions

Package

Dimensions in millimeters

TO-220 [ SINGLE GAUGE ]

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