LM117/LM217/LM317 - Adjustable Voltage Regulator - Data Sheet

Q: What output voltage range do LM117/LM217/LM317 provide?

The output voltage is adjustable over a 1.2V to 37V range.

Q: How is the regulator output voltage set in the basic adjustable configuration?

Using a resistive divider: VO = VREF (1 + R2/R1) + IADJ·(R2/R1), with VREF defined between the output and adjustment terminals.

Q: What protection and operating features are included?

The devices include a complete series of protections such as current limiting, thermal shutdown, and SOA control.

Nov 2, 2026

Uploaded by Dewi_Sukmawati

LM117/LM217/LM317 are monolithic integrated positive adjustable voltage regulators in TO-220 and TO-3 packages, providing output voltage adjustable from 1.2V to 37V and load current above 1.5A (with lower limits in smaller packages). Key characteristics include 0.1% line/load regulation performance, internal reference voltage of 1.25V, current limiting, thermal shutdown, and SOA control. The document specifies absolute maximum ratings, thermal data, pin connections, ordering codes, electrical characteristics under defined test conditions, and application guidance using external resistor dividers and recommended capacitors/diodes.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages10

Reading Time25 min

AccessFree to download

Description

Absolute Maximum Rating

Thermal Data

Pin Connection and Ordering Number

Schematic Diagram

Electrical Characteristics

Application Information

Basic Adjustable Regulator

Capacitor and Protection Diodes Recommendations

Example Circuits Figures

LM117/217 LM317 1.2V TO 37V ADJUSTABLE VOLTAGE REGULATOR . OUTPUT VOLTAGE RANGE : 1 .2 TO 37V . OUTPUT CURRENT IN EXCESS OF 1 .5A (0.5A for TO-39) . 0. 1% LINE AND LOAD REGULATION . FLAGOEASTING OPERATION FOR HIGH VOLT- . COMPLETE SERIES OF PROTECTIONS : CURRENT LIMITING, THERMAL SHUTDOWN AND SOA CONTROL TO-3 DESCRIPTION The LM117/LM217/LM317 are monolithic integrated circuit in TO-220 and TO-3 packages intended for use as positive adjustable voltage regulators. They are designed to supply more than 1.5A of load current with an output voltage adjustable over a 1.2 to 37V range. The nominal output voltage is selected by means of only a resistive divider, making the device exceptionally easy to use and eliminating the stocking of many fixed regulators. TO-220 TO-39 ABSOLUTE MAXIMUM RATING Symbol Parameter Vi-o Input-output Differential Voltage IO Output Current Top Operating Junction Temperature for: Ptot Power Dissipation LM117 LM217 LM317 Value 40 Intenrally Limited -55 to 150 -25 to 150 0 to 125 Internally Limited Unit V oC oC oC THERMAL DATA Rthj-case Rthj-amb Thermal Resistance Junction-case Max Thermal Resistance Junction-ambient Max March 1993 TO-3 4 35 TO-220 3 50 ISOWATT220 4 60 TO-39 15 160 oC/W oC/W 1/10 LM117/LM217/LM317 PIN CONNECTION AND ORDERING NUMBER TO-220 TO-3 TO-3 Type LM117 LM217 LM317 TO-3 LM117K LM217K LM317K pin 1 = INPUT pin2 = ADJ pin3 = OUTPUT TO-220 LM217T LM317T ISOWATT220 LM217P LM317P TO-39 LM117H LM217H LM317H SCHEMATIC DIAGRAM LM117/LM217/LM317 Basic adjustable regulator. ELECTRICAL CHARACTERISTICS (Vi -Vo = 5 V, Io = 500 mA for TO-3 and TO-220, Io = 100 mA for TO-39, IMAX and P MAX according note 2, unless otherwise specified) Symbol Parameter Test Conditions LM117/LM217 LM317 Unit Min. Typ. Max. Min. Typ. Max. ∆Vo Line Regulation Vi -Vo = 3 to 40 V Tj = 25 oC 0.01 0.02 0.01 0.04 %/V 0.02 0.05 0.02 0.07 %/V ∆Vo Load Regulation Vo ≤ 5V Tj = 25 oC 5 15 5 25 mV Io = 10 mA to IMAX 20 50 20 70 mV Vo ≥ 5V Tj = 25 oC 0.1 0.3 0.1 0.5 % Io = 10 mA to IMAX 0.3 1 0.3 1.5 % IADJ Adjustment Pin 50 100 50 100 µA Current ∆ IADJ Adjustment Pin Vi -Vo = 2.5 to 40 V 0.2 5 0.2 5 µA Current Io = 10 mA to IMAX VREF Reference Voltage Vi -Vo = 2 .5 to 40 V [1.2 1.25 1.3](1.2 1.25 1.3) [1.2 1.25 1.3](1.2 1.25 1.3) V (between pin 3 and Io = 10 mA to IMAX pin 1) PD ≤ PMAX ∆Vo Output Voltage 1 1 % Vo Temperature Stability Io(min) Minimum Load Vi -Vo = 40 V 3.5 5 3.5 10 mA Current Io(max) Maximum Load Vi -Vo ≤ 15 V TO-3 1.5 2.2 1.5 2.2 A Current PD < PMAX TO-220 TO-39 0.5 0.8 0.5 0.8 A Vi -Vo = 40 V TO-3 0.4 0.4 A PD < PMAX TO-220 Tj = 25 oC TO-39 0.07 0.07 A eN Output Noise Voltage B = 10Hz to 10KHz 0.003 0.003 % (percentance of VO) Tj = 25 oC SVR Supply Voltage Tj = 25 oC CADJ=0 65 65 dB Rejection (*) f = 120 Hz CADJ=10µF 66 80 66 80 dB (*) CADJ is connected between pin 1 and ground. Note: (1) Unless otherwise specified the above specs, apply over the following conditions : LM 117 Tj = – 55 to 150°C; LM 217 Tj = – 25 to 150°C ; LM 317 Tj = 0 to 125°C. (2) IMAX: 1 .5 A for TO-3 and TO-220; 0 .5 A for TO-39 PMAX: 20 W for TO-3 and TO-220; 2 W for TO-39 LM117/LM217/LM317 Figure 1 : Output Current vs. Input-output Differential Voltage. Figure 2 : Dropout Voltage vs. Junction Temperature. Figure 3 : Reference Voltage vs. Junction APPLICATION INFORMATION The LM117/217/317 provides an internal reference voltage of 1 .25V between the output and adjustments terminals. This is used to set a constant current flow across an external resistor divider (see fig. 4), giving an output voltage VO of: R2 VO = VREF (1 + ) + IADJ R2 R1 The device was designed to minimize the term IADJ (100µA max) and to maintain it very constant with line and load changes. Usually, the error term IADJ ⋅ R2 can be neglect

FAQs

What output voltage range do LM117/LM217/LM317 provide?

The output voltage is adjustable over a 1.2V to 37V range.

How is the regulator output voltage set in the basic adjustable configuration?

Using a resistive divider: VO = VREF (1 + R2/R1) + IADJ·(R2/R1), with VREF defined between the output and adjustment terminals.

What protection and operating features are included?

The devices include a complete series of protections such as current limiting, thermal shutdown, and SOA control.

Nov 2, 2026

Uploaded by Dewi_Sukmawati