LM317-D - 1.5 A Adjustable Output, Positive Voltage Regulator

Nov 2, 2026

Uploaded by OKfine

LM317, NCV317 provides an adjustable positive voltage regulation range from 1.2 V to 37 V with output current exceeding 1.5 A. The device requires only two external resistors to set output voltage, and includes internal current limiting, thermal shutdown, and safe-area compensation to improve reliability. It supports applications such as local on-card regulation, programmable output regulation, and precision current regulation using a fixed resistor. Available packages include D2PAK-3 and TO-220 variants, including NCV for automotive use.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages12

Reading Time30 min

AccessFree to download

Features

Output adjustment and protection features

Applications and stability notes

Maximum Ratings

Input-output differential and temperature ranges

Electrical Characteristics

Line and load regulation

Reference voltage and noise

Thermal and stability parameters

LM317, NCV317 1.5 A Adjustable Output, Positive Voltage Regulator The LM317 is an adjustable 3−terminal positive voltage regulator capable of supplying in excess of 1.5 A over an output voltage range of 1.2 V to 37 V. This voltage regulator is exceptionally easy to use and requires only two external resistors to set the output voltage. Further, it employs internal current limiting, thermal shutdown and safe area compensation, making it essentially blow−out proof. The LM317 serves a wide variety of applications including local, on card regulation. This device can also be used to make a programmable output regulator, or by connecting a fixed resistor between the adjustment and output, the LM317 can be used as a precision current regulator. Features • Output Current in Excess of 1.5 A • Output Adjustable between 1.2 V and 37 V • Internal Thermal Overload Protection • Internal Short Circuit Current Limiting Constant with Temperature • Output Transistor Safe−Area Compensation • Floating Operation for High Voltage Applications • Eliminates Stocking many Fixed Voltages • Available in Surface Mount D2PAK−3, and Standard 3−Lead Transistor Package • NCV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC−Q100 Qualified and PPAP Capable • These are Pb−Free Devices * Cin is required if regulator is located an appreciable distance from power supply filter. ** CO is not needed for stability, however, it does improve transient response. Vout 􀀂 1.25 V 􀀃 1 􀀄 RR~~2~~1􀀅 􀀄 IAdj R2 Since IAdj is controlled to less than 100 􀀂A, the error associated with this term is negligible in most applications. Figure 1. Standard Application [www.onsemi.com](www.onsemi.com) D2PAK−3 D2T SUFFIX CASE 936 Heatsink surface (shown as terminal 4 incase outline drawing) is connected to Pin 2. TO−220 T SUFFIX CASE 221AB Pin 1. Adjust 2. Vout 3. Vin 12 3 Heatsink surface connected to Pin 2. DEVICE MARKING INFORMATION See general marking information in the device marking section on page 10 of this data sheet. LM317, NCV317 MAXIMUM RATINGS | Rating | Symbol | Value | Unit | | --- | --- | --- | --- | | Input−Output Voltage Differential | VI−VO | −0.3 to 40 | Vdc | | Power Dissipation
Case 221A
TA = +25°C
Thermal Resistance, Junction−to−Ambient
Thermal Resistance, Junction−to−Case
Case 936 (D2PAK−3)
TA = +25°C
Thermal Resistance, Junction−to−Ambient
Thermal Resistance, Junction−to−Case | PD
􀀃 JA
􀀃 JC
PD
􀀃 JA
􀀃 JC | Internally Limited
65
5.0
Internally Limited
70
5.0 | W
°C/W
°C/W
W
°C/W
°C/W | | Operating Junction Temperature Range | TJ | −55 to +150 | °C | | Storage Temperature Range | Tstg | −65 to +150 | °C | Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. ELECTRICAL CHARACTERISTICS (VI−VO = 5.0 V; IO = 0.5 A for D2T and T packages; TJ = T low to Thigh(Note 1); Imax and Pmax (Note 2); unless otherwise noted.) | Characteristics | Figure | Symbol | Min | Typ | Max | Unit | | --- | --- | --- | --- | --- | --- | --- | | Line Regulation (Note 3), TA = +25°C, 3.0 V ≤ VI−VO ≤ 40 V | 1 | Reg line | − | 0.01 | 0.04 | %/V | | Load Regulation (Note 3), TA = +25°C, 10 mA ≤ IO ≤ Imax
VO ≤ 5.0 V
VO ≥ 5.0 V | 2 | Reg load | −
− | 5.0
0.1 | 25
0.5 | mV
% VO | | Thermal Regulation, TA = +25°C (Note 4), 20 ms Pulse | − | Regtherm | − | 0.03 | 0.07 | % VO/W | | Adjustment Pin Current | 3 | IAdj | − | 50 | 100 | 􀀂A | | Adjustment Pin Current Change, 2.5 V ≤ VI−VO≤ 40 V,
10 mA ≤ IL ≤ Imax , PD ≤ Pmax | 1, 2 | 􀀄IAdj | − | 0.2 | 5.0 | 􀀂A | | Reference Voltage, 3.0 V ≤ VI−VO≤ 40 V, 10 mA ≤ IO ≤ Imax , PD ≤ Pmax | 3 | V ref | 1.2 | 1.25 | 1.3 | V | | Line Regulation (Note 3), 3.0 V ≤ VI−VO ≤ 40 V | 1 | Reg line | −

FAQs

What output voltage range and current can LM317 provide?

LM317/NCV317 supports an output voltage range of 1.2 V to 37 V and can supply in excess of 1.5 A.

How is the output voltage set for LM317?

Output voltage is set using two external resistors, since the LM317 is an adjustable 3-terminal regulator.

What protections and reliability features are built into LM317?

LM317 includes internal current limiting, thermal shutdown, and output transistor safe-area compensation, helping it operate reliably under fault and thermal conditions.

Nov 2, 2026

Uploaded by OKfine