LM117K

1.5A Adjustable Regulator, 1.25V-37V, TO-3 Metal Can Package

3105

Effective Inventory
Go to Inquiry

Image for reference only

Manufacturer Part：

LM117K

Package：

TO-3 (Metal Can), 28.7 x 10.92 mm

Brand：
Product Categories：
Quality Commitment
Shipping & Payment
Service & Packaging
Product Manual
Other recommendations you may be interested in.

OC5A2B00

NCV887103D1R2G

NAE12S17-A

MIC4428YM

MIC2951-03BN

LTM4673Y

LTC3780IG

LTC3112EFE

Description

Product Overview

The LM117K is a 1.5A three-terminal adjustable voltage regulator in a rugged TO-3 metal can package. Manufactured by Texas Instruments, this military-grade device operates over a -55°C to +150°C temperature range and provides an adjustable output from 1.25V to 37V using only two external resistors. The LM117 represents the extended-temperature version of the industry-standard LM317, offering the same classic floating regulator architecture with internal current limiting, thermal shutdown, and safe-area compensation for maximum reliability in high-power and harsh-environment applications.

Key Specifications

Parameter Value
Manufacturer Texas Instruments
Part Number LM117K
Product Category Adjustable Linear Regulators
Output Type Adjustable
Output Voltage Range 1.25V to 37V
Output Current 1.5A
Input-Output Differential 1.2V min, 40V max
Line Regulation 0.01% typical
Load Regulation 0.1% typical
Reference Voltage 1.25V ±1%
Package / Case TO-3 (Metal Can)
Operating Temperature -55°C to +150°C

Features

  • Adjustable output from 1.25V to 37V with two resistors
  • 1.5A output current capability
  • Military temperature range: -55°C to +150°C
  • Internal current limiting with foldback
  • Thermal shutdown protection
  • Safe-area (SOA) compensation for pass transistor
  • Rugged TO-3 metal can package for high power dissipation
  • Standard 3-terminal pinout, easy drop-in replacement

Applications

  • Military and aerospace power systems
  • High-power adjustable bench power supplies
  • Industrial motor drives and controls
  • High-temperature environment equipment
  • High-reliability power conditioning systems

The LM117K is a high-reliability three-terminal adjustable voltage regulator supplied in a robust TO-3 metal can package. Manufactured by Texas Instruments, the LM117 is the military/extended temperature version of the world-famous LM317 regulator, rated for continuous operation from -55°C to +150°C.

Using the classic floating regulator architecture pioneered by National Semiconductor, the LM117 maintains a precise 1.25V reference voltage between its OUTPUT and ADJUST pins. With only two external resistors, users can set the output to any voltage between 1.25V and 37V. The device floats on top of the output voltage, making it insensitive to variations in input voltage relative to ground.

The TO-3 metal can package provides exceptional thermal conductivity and mechanical strength. The metal case is electrically connected to the input (collector of the pass transistor), enabling direct mounting to a heat sink for high-power dissipation. This package style is the standard for high-reliability military and industrial applications.

Comprehensive on-chip protection includes internal current limiting with foldback characteristics, thermal shutdown, and safe-operating-area (SOA) compensation. These features ensure the regulator survives and recovers from fault conditions such as output short circuits and thermal overload.

The LM117 employs a floating regulator architecture that differs from conventional ground-referenced regulators:

1. Floating Reference Principle: The regulator maintains a precise 1.25V bandgap reference between the OUTPUT and ADJUST pins. This voltage drives a constant current (1.25V/R1) through resistor R1, which then flows through R2 to ground, creating the output voltage: VOUT = 1.25V × (1 + R2/R1).

2. Error Amplifier: The error amplifier compares the 1.25V reference against the voltage across R1. It adjusts the base drive to the pass transistor to maintain this voltage precisely, regardless of input or load variations.

3. Darlington Pass Transistor: A Darlington-connected NPN pair provides the high current gain needed to drive 1.5A of output current while maintaining sufficient base drive from the error amplifier. The tradeoff is a higher dropout voltage (~1.2V to 2.5V depending on load).

4. Current Limiting: A foldback current limit circuit reduces the output current under short-circuit conditions, minimizing power dissipation in the pass transistor while still providing sufficient current for start-up.

5. Thermal Shutdown: When the die temperature reaches approximately 165°C, the thermal shutdown circuit disables the pass transistor. The device automatically restarts when it cools below the hysteresis threshold.

6. SOA Compensation: As the input-output voltage differential increases, the current limit threshold is reduced to keep the pass transistor operating within its safe operating area, preventing second breakdown failures.

Pin Name Type Description
Case INPUT Input Input voltage (collector of pass transistor). The TO-3 metal case is electrically connected to this pin. Maximum 40V input-output differential.
1 OUTPUT Output Regulated output voltage (emitter of pass transistor). Connect output capacitor and load here.
2 ADJUST Input Adjust pin. Connect bottom of resistor divider (R2) here. The ADJUST pin is nominally 1.25V below the OUTPUT pin.

Note: The metal case is at INPUT potential. Use an insulator when mounting to a grounded heat sink if INPUT is not at ground potential.

  • Military-grade power supply systems
  • Aerospace and avionics power conditioning
  • Industrial adjustable power supplies (0-30V, 0-36V)
  • Laboratory bench power supply designs
  • High-temperature downhole and drilling equipment
Manufacturer Part Number Package Notes
Texas Instruments LM317K TO-3 Commercial grade (0 to 125°C)
Texas Instruments LM138K TO-3 5A higher current version
Texas Instruments LM150K TO-3 3A medium current version
STMicroelectronics LM317K TO-3 Pin-compatible commercial alternative
ON Semiconductor LM317K TO-3 Direct substitute
Linear Tech LT1083CK TO-3 7.5A high-performance option
Recommend Parts

OC5A2B00

High-voltage buck LED driver, 6-60V input, constant current up to 3A, PWM+analog dimming, ESOP-8

Brand:

Package:

ESOP-8 (4.9 x 3.9 x 0.8 mm, exposed thermal pad)

In stock:

6500pcs

Cargo cycle: 3~7 Days
The minimum order is 1

Go to Inquiry

NCV887103D1R2G

Automotive boost controller, 3.2-40V input, 340kHz, peak current mode, AEC-Q100, SOIC-8

Brand:

Package:

SOIC-8 (4.9 x 3.9 x 1.5 mm, 1.27mm pitch)

In stock:

10000pcs

Cargo cycle: 3~7 Days
The minimum order is 1

Go to Inquiry

NAE12S17-A

17W isolated DC-DC converter, 12V input, 15V output, 1500VDC isolation, DIP package, industrial

Brand:

Package:

DIP Module (50.8 x 25.4 x 10.2 mm, through-hole)

In stock:

2400pcs

Cargo cycle: 3~7 Days
The minimum order is 1

Go to Inquiry

MIC4428YM

Dual 1.5A low-side MOSFET driver, 4.5-18V, 15ns rise time, TTL/CMOS input, SOIC-8, industrial

Brand:

Package:

SOIC-8 (150 mils body width)

In stock:

8400pcs

Cargo cycle: 3~7 Days
The minimum order is 1

Go to Inquiry

MIC2951-03BN

3.0V 500mA LDO regulator, ultra-low dropout 58mV, 26V input, reverse battery protection, TO-263-5

Brand:

Package:

TO-263-5 (D2PAK, 10.16 x 10.67 mm)

In stock:

9100pcs

Cargo cycle: 3~7 Days
The minimum order is 1

Go to Inquiry

LTM4673Y

Quad-Output 5A Digital μModule Regulator, PMBus, 4.5V-17V In, BGA-144

Brand:

Package:

BGA-144 (15 x 9 x 3.42 mm)

In stock:

4236pcs

Cargo cycle: 3~7 Days
The minimum order is 1

Go to Inquiry
Quality Assurance

Quality is the core foundation of our long-term global cooperation. With over 20 years of experience in the electronic component industry, Materialparts has built a strict and standardized quality management system covering component sourcing, incoming inspection, full-batch testing, packaging and delivery. We are committed to delivering 100% genuine, high-reliability electronic components for industrial control, automotive electronics, consumer electronics and medical device industries, and fully safeguarding your production and R&D projects.

1. Authorized & Genuine Sourcing Promise

All of our electronic components are procured from official authorized distributors and original manufacturers. We strictly reject counterfeits, refurbished parts, disassembled components and gray-market goods. Every product is guaranteed to be brand-new original parts and fully consistent with the original technical parameters. For branded products such as NXP IC series, we maintain complete supply channel documents to realize full product traceability.

2. Strict Full-batch Quality Inspection

We implement 100% full-batch quality control for all goods before shipment. Our professional QC team conducts multi-dimensional tests including appearance inspection, electrical parameter testing, performance verification and packaging check. Each batch of components is attached with complete inspection reports and batch records. We stick to zero-tolerance standards for defective products to ensure every piece of component meets industrial application requirements.

3. Industry Standard Compliance

Our products comply with a variety of international industry quality standards to adapt to high-standard application scenarios:
  • Automotive Electronics: All automotive-grade components pass AEC-Q series certification, featuring excellent stability and durability to adapt to complex vehicle operating environments.
  • Medical Devices: High-reliability components meet medical industry safety and compliance regulations, ensuring stable operation for medical equipment.
  • Industrial Control & Consumer Electronics: Products conform to universal international electronic industry standards, suitable for long-term continuous operation of various equipment.

4. Professional Reliability Control

For static-sensitive, moisture-sensitive and precision components such as ICs, PCBs, sensors and connectors, we carry out reliability screening in advance. Combined with standardized ESD anti-static packaging and vacuum moisture-proof packaging, we avoid component damage caused by static electricity, dampness or collision during storage and transportation, and retain the original performance of products.

5. Traceability Management System

We establish a complete product traceability system. Each batch of goods corresponds to independent batch number, sourcing record, inspection record and delivery record. Customers can query the whole lifecycle information of components at any time. This system effectively solves quality risks and facilitates after-sales handling and production quality control for your company.

6. After-sales Quality Guarantee

If any product is confirmed to have non-conformity quality problems due to our reasons after receipt, we provide free return, exchange and supplementary delivery services. Our professional quality team will also conduct root cause analysis to optimize our quality control process. We respond to quality feedback within 24 hours to resolve your worries efficiently.

Contact Us

If you have inquiries about our quality standards, inspection procedures or product certification documents, please feel free to contact us:

 

Email: info@ic-vendor.com
Tel / WhatsApp: +86 13760382860
Address: Room 2919, Guoli Building, Huaqiang North, Futian District, Shenzhen, Guangdong, China

 

Shipping & Payment

Materialparts is a professional global supplier of electronic components with over 20 years of industry experience. We provide one-stop supply of passive components, integrated circuits, as well as parts for industrial control, automotive electronics, consumer electronics and medical devices. Below are the unified shipping and payment policies applicable to all orders, samples and bulk purchases worldwide.

1. Payment Terms

We offer a variety of secure and convenient payment methods to meet diverse business cooperation needs. Details are as follows:
  1. Accepted Payment Methods
  • T/T (Bank Wire Transfer): The primary settlement method for bulk orders and a widely used international payment channel.
  • PayPal: Ideal for small orders, sample orders and quick payments.

  1. Settlement Currency

     

    US Dollar (USD) is the default settlement currency. RMB is available for domestic customers.

  2. Bank Charges

     

    All transfer fees, intermediary bank charges and other remittance-related expenses shall be borne by the buyer.

  3. Payment Requirements
  • Sample and small orders: Shipment will be arranged upon full payment.
  • In-stock bulk orders: Goods will be delivered within 2 to 3 working days after full payment.

2. Shipping & Delivery

We partner with leading global logistics providers to ensure safe and fast delivery worldwide. Relevant details are listed below:
  1. Logistics Partners
  • International Express: DHL, FedEx, UPS, TNT
  • Economy Logistics: Air freight and sea freight for large-volume cargo
  • Domestic Delivery: SF Express, Yunda Express
  1. Order Processing Time
  • In-stock items: Orders confirmed and fully paid before 14:00 (GMT+8) will be shipped on the same day. All other orders will be dispatched within 1 to 2 working days.
  • Out-of-stock or sourced items: The delivery lead time will be confirmed separately according to brand and inventory status.
  1. Estimated Transit Time
  • International Express: 3 – 7 working days globally
  • Air Freight: 7 – 12 working days
  • Sea Freight: 25 – 40 working days for heavy and large bulk cargo
  1. Shipping Fee Rules
  • Shipping cost is calculated based on package weight, volume, destination and delivery method.
  • Both freight prepaid and freight collect are available. Please provide your courier account number in advance if you choose freight collect.
  • Free international express delivery is offered for large orders. Terms for long-term partners can be negotiated separately.
  1. Shipment Tracking
     

    Within 24 hours after dispatch, we will send the tracking number, commercial invoice, packing list and other documents to your email or communication account. You may check the shipment status online in real time.

3. General Order Rules & Notes

  1. MOQ & Sample Service

     

    We support flexible minimum order quantities for samples, small-batch and large-batch orders. All sample orders shall comply with the above shipping and payment policies.

  2. Packaging Standard

     

    All electronic components are packed with professional anti-static and shockproof materials. Original factory packaging is available for branded chips and integrated circuits.

4. Customs & Liability Statement

  1. Import Duties & Taxes

     

    All import duties, customs clearance fees and local taxes incurred for international shipments shall be borne by the buyer. We will provide complete customs documents to assist you with clearance procedures.

  2. Handling of Lost or Damaged Goods
  • In case of loss or severe damage during transit, please contact us within 48 hours after receiving the tracking information. We will assist you in filing a claim with the logistics provider.
  • We shall not be liable for any losses caused by incorrect delivery address, wrong contact information or the buyer’s refusal to complete customs clearance.

5. Local Pickup in Shenzhen

Local pickup service is available for customers in Shenzhen and surrounding areas:
  • Address: Room 2919, Guoli Building, Huaqiang North, Futian District, Shenzhen, Guangdong Province, China
  • Business Hours: 09:00 – 18:00, Monday to Friday. Closed on weekends and official public holidays.
  • Notice: Please make an appointment via email or communication tools one day in advance, and present your order information upon pickup.

Contact Information

Email: info@ic-vendor.com

Tel / WhatsApp: +86 13760382860

Service & Packaging

Materialparts is a professional electronic component supplier based in Shenzhen, China, with over 20 years of global trading experience. We integrate component procurement, quality inspection, technical support, customized packaging, and global delivery services to provide one-stop supply chain solutions. Our business covers industrial control, automotive electronics, consumer electronics, medical devices and other industries. We always adhere to genuine sources, stable supply and considerate after-sales service.

Core Services

1. One-stop Sourcing & BOM Support

We specialize in a full range of passive and active electronic components, including SMD resistors, power resistors, connectors, aviation connectors, LED beads, flexible circuit boards, printed circuit boards, and integrated circuits. Our professional team provides BOM list consolidation, component matching, and alternative model recommendation services. We support sample orders, small-batch trial production, and mass production orders with flexible MOQs to meet diverse procurement needs.

2. Genuine Product Guarantee & Full-process Quality Inspection

All products are sourced from official authorized channels and are 100% original genuine parts. Every batch of goods undergoes strict full-process quality inspection before delivery, with complete batch records and traceability documents provided. Our products comply with AEC-Q standards for automotive electronics and high-reliability specifications for medical devices. We eliminate counterfeits, refurbished parts and defective products from the source to secure your project production.

3. Fast Quotation & Order Processing

Our customer service team responds promptly to inquiries and quotation requests. All in-stock orders will be processed within one working day. We provide stocking reservation services for long-term cooperative customers, effectively solving problems such as component shortages and unstable supply chains.

4. Professional Technical Support

Our senior engineer team provides free technical consultation, model selection guidance and original manufacturer datasheets. We assist customers in solving problems related to product R&D, circuit design and component application, providing reliable technical support for project progress.

5. Sourcing for Special Components

Relying on our global supply chain network, we professionally source scarce components, obsolete parts and customized special components to efficiently solve your procurement difficulties.

6. Global Logistics & Document Services

We cooperate with mainstream international logistics providers including DHL, FedEx, UPS and TNT to achieve fast global delivery. We can provide complete export documents such as customs declaration files, commercial invoices and packing lists to ensure smooth customs clearance for international shipments. Local pickup is also available for customers in Shenzhen, China.

Professional Packaging Standards

Electronic components are sensitive to static electricity, collision, moisture and dust. We adopt industry-standard anti-static packaging solutions to fully ensure the integrity of goods during transportation and storage.

1. General Packaging Specifications

  • All components are packed separately to avoid damage caused by friction and collision;
  • Shockproof buffer materials are added for fragile products to ensure transportation safety;
  • Each package is clearly marked with part number, quantity, batch number and specifications for easy inventory counting and management.

2. Classified Professional Packaging

  • Anti-static Packaging: Static-sensitive components such as chips, circuit boards and sensors are packaged with anti-static bags, shielding boxes and conductive foam in strict accordance with international anti-static standards to prevent static damage.
  • Vacuum Moisture-proof Packaging: Moisture-sensitive components are vacuum-sealed with desiccants to isolate humid air, suitable for ocean transportation and long-term storage.
  • Original Factory Packaging: Integrated circuits of brands such as NXP are delivered with original reels, trays or tubes by default, retaining complete original packaging and adapting to automated SMT production lines.
  • Discrete Device Packaging: Discrete devices such as SMD resistors, power resistors and LEDs are quantitatively and classifiedly packaged with accurate quantity and clear marking.
  • Connector / Aviation Connector Packaging: Hard outer packaging is adopted to prevent pin bending and structural deformation.

3. Custom Packaging Services

We provide value-added services including personalized packaging, custom labeling and re-reeling according to customer requirements, fully matching your production and warehouse management standards.

Contact Information

For service consultation or packaging customization, please feel free to contact us:
Email: info@ic-vendor.com
Tel / WhatsApp: +86 13760382860
Address: Room 2919, Guoli Building, Huaqiang North, Futian District, Shenzhen, Guangdong, China
 

Online Inquiry Form

Support Excel, PDF, CSV format files for full BOM list quotation

Submit your component procurement and custom packaging needs via the form below. We will provide a detailed quotation and professional solution within 1–8 working hours.

Company
insights
Industries
All Products
Integrated Circuits
C&I Devices
Discrete
Memory Chips
MPUs & MCUs