Datasheet

ManualsBrandsST ManualsIntegrated Circuits (ICs)Linear Voltage Regulator, Polar, 1.2 ... 37V, 100mA, SOIC

April 9, 2008

LM317L

3-Terminal Adjustable Regulator

General Description

The LM317L is an adjustable 3-terminal positive voltage reg-

ulator capable of supplying 100mA over a 1.2V to 37V output

range. It is exceptionally easy to use and requires only two

external resistors to set the output voltage. Further, both line

and load regulation are better than standard fixed regulators.

Also, the LM317L is available packaged in a standard TO-92

transistor package which is easy to use.

In addition to higher performance than fixed regulators, the

LM317L offers full overload protection. Included on the chip

are current limit, thermal overload protection and safe area

protection. All overload protection circuitry remains fully func-

tional even if the adjustment terminal is disconnected.

Normally, no capacitors are needed unless the device is sit-

uated more than 6 inches from the input filter capacitors in

which case an input bypass is needed. An optional output ca-

pacitor can be added to improve transient response. The

adjustment terminal can be bypassed to achieve very high

ripple rejection ratios which are difficult to achieve with stan-

dard 3-terminal regulators.

Besides replacing fixed regulators, the LM317L is useful in a

wide variety of other applications. Since the regulator is “float-

ing” and sees only the input-to-output differential voltage,

supplies of several hundred volts can be regulated as long as

the maximum input-to-output differential is not exceeded.

Also, it makes an especially simple adjustable switching reg-

ulator, a programmable output regulator, or by connecting a

fixed resistor between the adjustment and output, the LM317L

can be used as a precision current regulator. Supplies with

electronic shutdown can be achieved by clamping the adjust-

ment terminal to ground which programs the output to 1.2V

where most loads draw little current.

The LM317L is available in a standard TO-92 transistor pack-

age, the SO-8 package, and 6-Bump micro SMD package.

The LM317L is rated for operation over a −25°C to 125°C

range.

Features

■

Adjustable output down to 1.2V

■

Guaranteed 100mA output current

■

Line regulation typically 0.01%V

■

Load regulation typically 0.1%

■

Current limit constant with temperature

■

Eliminates the need to stock many voltages

■

Standard 3-lead transistor package

■

80dB ripple rejection

■

Available in TO-92, SO-8, or 6-Bump micro SMD package

■

Output is short circuit protected

■

See AN-1112 for micro SMD considerations

Connection Diagrams

TO-92 Plastic package

906404

8-Pin SOIC

906405

Top View

LM317L 3-Terminal Adjustable Regulator

Summary of content (20 pages)

PAGE 1
LM317L 3-Terminal Adjustable Regulator General Description The LM317L is an adjustable 3-terminal positive voltage regulator capable of supplying 100mA over a 1.2V to 37V output range. It is exceptionally easy to use and requires only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators. Also, the LM317L is available packaged in a standard TO-92 transistor package which is easy to use.
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LM317L 6-Bump micro SMD micro SMD Laser Mark 906450 906449 *NC = Not Internally connected. Top View (Bump Side Down) Ordering Information Package Marking Media Transport TO-92 Package LM317LZ LM317LZ 1.
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If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Power Dissipation Input-Output Voltage Differential Operating Junction Temperature Range Internally Limited 40V −55°C to +150°C 260°C 2kV −40°C to +125°C Electrical Characteristics (Note 2) Parameter Typ Max Units TJ = 25°C, 3V ≤ (VIN − VOUT) ≤ 40V, IL ≤ 20mA (Note 3) 0.01 0.
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LM317L Typical Performance Characteristics (Output capacitor = 0μF unless otherwise noted.) Load Regulation Current Limit 906434 906435 Adjustment Current Dropout Voltage 906436 906437 Reference Voltage Temperature Stability Minimum Operating Current 906438 www.national.
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LM317L Ripple Rejection Ripple Rejection 906441 906440 Output Impedance Line Transient Response 906442 906443 Load Transient Response Thermal Regulation 906444 906445 5 www.national.
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LM317L Although the LM317L is stable with no output capacitors, like any feedback circuit, certain values of external capacitance can cause excessive ringing. This occurs with values between 500pF and 5000pF. A 1μF solid tantalum (or 25μF aluminum electrolytic) on the output swamps this effect and insures stability. Application Hints In operation, the LM317L develops a nominal 1.25V reference voltage, VREF, between the output and adjustment terminal.
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the rate of decrease of VIN. In the LM317L, this discharge path is through a large junction that is able to sustain a 2A surge with no problem. This is not true of other types of positive regulators. For output capacitors of 25 μF or less, the LM317L's ballast resistors and output structure limit the peak current to a low enough level so that there is no need to use a protection diode. The bypass capacitor on the adjustment terminal can discharge through a low current junction.
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www.national.
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LM317L Slow Turn-On 15V Regulator Typical Applications Digitally Selected Outputs 906415 Adjustable Regulator with Improved Ripple Rejection 906411 *Sets maximum VOUT High Gain Amplifier 906416 †Solid tantalum *Discharges C1 if output is shorted to ground High Stability 10V Regulator 906412 Adjustable Current Limiter 906413 12 ≤ R1 ≤ 240 906417 Precision Current Limiter Adjustable Regulator with Current Limiter 906414 906418 Short circuit current is approximately 600 mV/R3, or 60mA (comp
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LM317L 0V–30V Regulator Power Follower 906419 906421 Full output current not available at high input-output voltages Regulator With 15mA Short Circuit Current 906420 Adjusting Multiple On-Card Regulators with Single Control* 906422 *All outputs within ± 100mV †Minimum load −5mA www.national.
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5V Logic Regulator with Electronic Shutdown* 906423 1.2V–12V Regulator with Minimum Program Current *Minimum output ≈ 1.2V 906426 Current Limited 6V Charger *Minimum load current ≈ 2 mA 906424 50mA Constant Current Battery Charger for Nickel-Cadmium Batteries 906427 *Sets peak current, IPEAK = 0.6V/R1 **1000μF is recommended to filter out any input transients. 906425 11 www.national.
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LM317L Short Circuit Protected 80V Supply 906428 Basic High Voltage Regulator 906429 Q1, Q2: NSD134 or similar C1, C2: 1μF, 200V mylar** *Heat sink www.national.
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LM317L Precision High Voltage Regulator 906430 Q1, Q2: NSD134 or similar C1, C2: 1μF, 200V mylar** *Heat sink **Mylar is a registered trademark of DuPont Co. Tracking Regulator R1, R2 = matched resistors with good TC tracking Regulator With Trimmable Output Voltage 906432 Trim Procedure: —If VOUT is 23.08V or higher, cut out R3 (if lower, don't cut it out). —Then if VOUT is 22.47V or higher, cut out R4 (if lower, don't). —Then if VOUT is 22.16V or higher, cut out R5 (if lower, don't).
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LM317L Precision Reference with Short-Circuit Proof Output 906433 *R1–R4 from thin-film network, Beckman 694-3-R2K-D or similar 1.2V-25 Adjustable Regulator Lamp Flasher 906401 Full output current not available at high input-output voltages †Optional—improves transient response *Needed if device is more than 6 inches from filter capacitors 906403 Output rate—4 flashes per second at 10% duty cycle Fully Protected (Bulletproof) Lamp Driver 906402 www.national.
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LM317L Physical Dimensions inches (millimeters) unless otherwise noted SO-8 Molded Package NS Package Number M08A 15 www.national.
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LM317L TO-92 Plastic Package (Z) NS Package Number Z03A www.national.
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LM317L NOTE: UNLESS OTHERWISE SPECIFIED. 1. EPOXY COATING 2. 63Sn/37Pb EUTECTIC BUMP. 3. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD. 4. PIN A1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION PINS ARE NUMBERED COUNTERCLOCKWISE. 5. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH, X2 IS PACKAGE LENGTH AND X3 IS PACKAGE HEIGHT. 6. REFERENCE JEDEC REGISTRATION MO-211, VARIATION BC. 6-Bump micro SMD NS Package Number BPA06HPB X1 = 0.955 X2 = 1.615 X3 =0.
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LM317L NOTE: UNLESS OTHERWISE SPECIFIED. 1. EPOXY COATING 2. 63Sn/37Pb EUTECTIC BUMP. 3. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD. 4. PIN A1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION PINS ARE NUMBERED COUNTERCLOCKWISE. 5. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH, X2 IS PACKAGE LENGTH AND X3 IS PACKAGE HEIGHT. 6. REFERENCE JEDEC REGISTRATION MO-211, VARIATION BC. 6-Bump micro SMD NS Package Number TPA06HPA X1 = 0.955 X2 = 1.615 X3 =0.
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LM317L Notes 19 www.national.
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LM317L 3-Terminal Adjustable Regulator Notes For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Design Support Amplifiers www.national.com/amplifiers WEBENCH www.national.com/webench Audio www.national.com/audio Analog University www.national.com/AU Clock Conditioners www.national.com/timing App Notes www.national.com/appnotes Data Converters www.national.com/adc Distributors www.national.com/contacts Displays www.