UMW LM317 - Adjustable 3-Terminal Positive Voltage Regulator - Description

Q: What output voltage range and load current does UMW LM317 support?

LM317 provides an adjustable positive output voltage from 1.2V to 37V and supports more than 1.5A load current.

Q: What internal protections are included in the LM317?

The regulator includes internal current limiting, thermal shut-down, and safe area compensation, plus internal thermal overload protection and short-circuit current limiting.

Q: How is the LM317 output voltage typically set in the application circuit?

The document states VO=1.25V(1+R2/R1)+Iadj*R2, and notes capacitor placement requirements for performance depending on distance to the power supply filter.

Nov 2, 2026

Uploaded by AditGamingID

UMW LM317 is a monolithic adjustable 3-terminal positive voltage regulator designed to deliver more than 1.5A of load current. The output voltage is adjustable from 1.2V to 37V and uses internal current limiting, thermal shut-down, and safe area compensation. Internal features include thermal overload protection and short-circuit current limiting, along with output transistor SOA compensation. The document provides absolute maximum ratings, electrical characteristics such as line/load regulation, reference voltage, noise, ripple rejection, stability, thermal resistance, typical application formula, package outlines, and ordering information.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Description

Features

Pinning information

Absolute Maximum Rating

Electrical Characteristics

Typical Application

Package Outline Dimensions

TO-220-3L

SOT-223

TO-252

Ordering information

Disclaimer

UMW LM317 1.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 1.2 to 37V. It employs internal current limiting , thermal shut-down and safe area compensation. 2.Features Internal thermal overload protection Internal short circuit current limiting Output transistor safe operating area compensation 3.Pinning information ~~ ~~ SOT-223 TO-252-2L SOT-89-3L 4.Internal Block Digram Vadj UTD Semiconductor Co., Limited [www.umw-ic.com](www.umw-ic.com) Jan.2025 1 of 9 [www.umw-ic.com](www.umw-ic.com) UMW LM317 5.Absolute Maximum Rating | Parameter | | Symbol | Value | Units | | --- | --- | --- | --- | --- | | Input-Output Voltage Differential | | VI-VO | 40 | V | | Lead Temperature | | TLEAD | 230 | °C | | Power Dissipation | TO-220 | PD | Internally limited | W | | | TO-252 | | 2 | W | | | SOT-223 | | 1 | W | | Junction Temperature Range | | TJ | -40 to 125 | °C | | Storage Temperature Range | | TSTG | -55 to 125 | °C | | Temperature Coefficient of Output Voltage | | ΔVO/ΔT | ±0.02 | %/°C | 2 of 9 UTD Semiconductor Co., Limited Jan.2025 [www.umw-ic.com](www.umw-ic.com) UMW LM317 6. Electrical Characteristics (VO-VI=5V, IO=0 .5A, 0°C≤TJ≤+125°C, IMAX=1 .5A, PDMAX=20W, unless otherwise specified) | Parameter | Symbol | Conditions | | Min | Typ | Max | Units | | --- | --- | --- | --- | --- | --- | --- | --- | | Line Regulation (note1) | Rline | TA=25°C, 3V≤VI-VO≤40V | | | 0.01 | 0.04 | %/V | | | | 3V≤VI-VO≤40V | | | 0.02 | 0.07 | | | Load Regulation (note1) | Rload | TA=25°C, 10mA≤IO≤IMAX | | | | | mV | | | | VO<5V | | | 18 | 25 | | | | | VO≥5V | | | 0.4 | 0.5 | | | | | 10mA≤IO≤IMAX | | | | | %VO | | | | VO<5V | | | 40 | 70 | | | | | VO≥5V | | | 0.8 | 1.5 | | | Adjustable Pin Current | IADJ | | | | 46 | 100 | µA | | Adjustable Pin Current Change | ΔIADJ | 3V≤VI-VO≤40V
10mA≤IO≤IMAX, PD≤ PMAX | | | 2 | 5 | | | Reference Voltage | VREF | 3V≤VIN-VO≤40V
10mA≤IO≤IMAX, PD≤ PMAX | | 1.2 | 1.25 | 1.3 | V | | Temperature Stability | STT | | | | 0.7 | | %/VO | | Minimum Load Current to Maintain
Regulation | IL(MIN) | VI-VO=40V | | | 3.5 | 12 | mA | | Maximum Output Current | IO(MAX) | VI-VO≤15V, PD≤PMAX | TA=25°C | 1 | 2.2 | | A | | | | VI-VO≤40V, PD≤PMAX | | | 0.3 | | | | RMS Noise,% of VOUT | eN | TA=25°C, 10Hz≤f≤10KHz | | | 0.003 | 0.01 | %/VO | | Ripple Rejection | RR | VO=10V, f=120Hz without CADJ | | 66 | 60 | | dB | | | | CADJ=10µF(note2) | | | 75 | | | | Long-Term Stability,TJ=THIGH | ST | TA=25°C for end point
mesasurements, 1000HR | | | 0.3 | 1 | % | | Thermal Resistance Junction to case | RθJC | | | | 25.2 | | °C/W | Notes: 1. Load and line regulation are specified at constant junction temperature. Change in VD due to heating effects must betaken into account separately. Pulse testing with low duty is used. (PMAX=20W) 2.CADJ . when used, is connected between the adjustment pin and ground. UTD Semiconductor Co., Limited Jan.2025 3 of 9 [www.umw-ic.com](www.umw-ic.com) UMW LM317 7.Typical Application OUTPUT VO=1.25V(1+R2/R1)+Iadj R2 Ci is required when regulator is located an appreciable distance from power supply filter. Co is not needed for stability , however, it does improve transient response. Since IADJ is controlled to less than 100µA, the error associated with this term is negligible in most applications [www.umw-ic.com](www.umw-ic.com) UMW LM317 8.1TO-220-3L Package Outline Dimensions DIMENSIONS (mm are the original dimensions) | Symbol | A | A1 | b | b1 | c | c1 | D | E | E1 | e | e1 | F | h | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Min | 4.470 | 2.520 | 0.710 | 1.170 | 0.310 | 1.170 | 10 .010 | 8.500 | 12 .060 | 2 .540
TYP | 4.980 | 2.590 | 0.000 | | Max | 4.670

FAQs

What output voltage range and load current does UMW LM317 support?

LM317 provides an adjustable positive output voltage from 1.2V to 37V and supports more than 1.5A load current.

What internal protections are included in the LM317?

The regulator includes internal current limiting, thermal shut-down, and safe area compensation, plus internal thermal overload protection and short-circuit current limiting.

How is the LM317 output voltage typically set in the application circuit?

The document states VO=1.25V(1+R2/R1)+Iadj*R2, and notes capacitor placement requirements for performance depending on distance to the power supply filter.

Nov 2, 2026

Uploaded by AditGamingID