LM317BD2T Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LM317BD2T is a linear positive adjustable voltage regulator IC manufactured by onsemi, rated for 1.5A output current in a D2PAK-3 surface mount package. This component is classified as obsolete, which necessitates identification of active equivalent and substitute parts for new designs and production continuity. The LM317 series provides adjustable output voltage regulation from 1.2V to 37V with integrated protection features including over-current, over-temperature, and short-circuit protection.

Substiute Parts

LM317BD2T

onsemiIn Stock: 4790LM317BD2T Datasheet

Current PartRFQ

LM317BD2TG

onsemiIn Stock: 485272LM317BD2TG Datasheet

DirectRFQ

LM317BD2TR4G

onsemiIn Stock: 45137LM317BD2TR4G Datasheet

SimilarRFQ

LM317D2T-TR

STMicroelectronicsIn Stock: 669078LM317D2T-TR Datasheet

DirectRFQ

LM317KTTR

Texas InstrumentsIn Stock: 133229LM317KTTR Datasheet

SimilarRFQ

LM317MDT-TR

STMicroelectronicsIn Stock: 150266LM317MDT-TR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM317BD2T is determined by the following critical parameters:

Primary Substitution Criteria:

• Base product number: LM317
• Output configuration: Positive
• Output type: Adjustable
• Voltage range: Input (Max) 40V, Output 1.2V to 37V
• Current rating: 1.5A
• Protection features: Over Current, Over Temperature, Short Circuit
• Mounting type: Surface Mount
• Package compatibility: D2PAK-3 or equivalent TO-263-3 footprint

Substitution Categories:

Direct Equivalents (Identical Electrical & Package Specifications):

• LM317BD2TG (onsemi) - Active status, Tube packaging, ROHS3 compliant
• LM317BD2TR4G (onsemi) - Active status, Cut Tape & Digi-Reel packaging, ROHS3 compliant

Cross-Manufacturer Equivalents (Identical Electrical Specifications, Same Package):

• LM317D2T-TR (STMicroelectronics) - Active status, Cut Tape & Digi-Reel packaging, ROHS3 compliant, operating temperature 0°C ~ 125°C

Similar Parts (Functional Equivalents with Package or Current Variations):

• LM317KTTR (Texas Instruments) - Active status, TO-263 (DDPAK-3) package, 1.5A rating, operating temperature 0°C ~ 125°C, MSL-3
• LM317MDT-TR (STMicroelectronics) - Active status, DPAK package, reduced to 500mA output current, operating temperature 0°C ~ 125°C

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Specifications & Footprint):

LM317BD2TG and LM317BD2TR4G are the primary direct substitutes for the obsolete LM317BD2T. Both are manufactured by onsemi with identical electrical specifications and D2PAK-3 package compatibility. The distinction between these two is packaging format: LM317BD2TG is supplied in Tube packaging, while LM317BD2TR4G is supplied in Cut Tape & Digi-Reel format. Both achieve ROHS3 compliance, addressing the RoHS non-compliance status of the original part.

For Cross-Manufacturer Equivalence:

LM317D2T-TR (STMicroelectronics) provides identical electrical performance and D2PAK package compatibility with ROHS3 compliance. The operating temperature range is reduced to 0°C ~ 125°C compared to the original -40°C ~ 125°C specification. This part is suitable for applications where the lower temperature limit does not conflict with system requirements.

For Applications with Package Flexibility:

LM317KTTR (Texas Instruments) maintains 1.5A output current and full electrical equivalence but uses a TO-263 (DDPAK-3) package variant. This part is suitable for designs where PCB layout accommodates the DDPAK-3 footprint. Operating temperature is limited to 0°C ~ 125°C, and MSL rating is 3 (168 Hours).

For Current-Limited Applications:

LM317MDT-TR (STMicroelectronics) is suitable only for applications requiring maximum 500mA output current. This part uses a DPAK package and is not recommended as a direct replacement for 1.5A-rated designs.

Frequently Asked Questions (FAQ)

Q: Can LM317BD2TG directly replace LM317BD2T without PCB modifications?

A: Yes. LM317BD2TG is a direct equivalent with identical D2PAK-3 footprint, electrical specifications, and pin configuration. No PCB layout changes are required. The primary difference is product status (Active vs. Obsolete) and RoHS compliance improvement.

Q: What is the difference between LM317BD2TG and LM317BD2TR4G?

A: Both parts are electrically and mechanically identical. The difference is packaging format: LM317BD2TG is supplied in Tube packaging, while LM317BD2TR4G is supplied in Cut Tape & Digi-Reel format. Selection depends on assembly line requirements and quantity needs.

Q: Can LM317D2T-TR be used in applications requiring -40°C operation?

A: No. LM317D2T-TR has an operating temperature range of 0°C ~ 125°C, which does not include -40°C. For applications requiring the full -40°C ~ 125°C range, use LM317BD2TG or LM317BD2TR4G.

Q: Is LM317KTTR compatible with existing LM317BD2T PCB layouts?

A: LM317KTTR uses a TO-263 (DDPAK-3) package, which differs from the D2PAK-3 package of the original part. While both are TO-263 variants, pin configuration and footprint may differ. PCB layout verification is required before substitution.

Q: Why is LM317MDT-TR listed as a similar part rather than a direct substitute?

A: LM317MDT-TR has a reduced output current rating of 500mA compared to the 1.5A specification of LM317BD2T. It is suitable only for applications with lower current requirements. Additionally, it uses a DPAK package instead of D2PAK, requiring PCB redesign.

Q: Are all substitute parts RoHS compliant?

A: Yes. All active substitute parts listed (LM317BD2TG, LM317BD2TR4G, LM317D2T-TR, LM317KTTR, and LM317MDT-TR) are ROHS3 compliant, addressing the RoHS non-compliance status of the obsolete LM317BD2T.

Q: What is the MSL (Moisture Sensitivity Level) consideration for these parts?

A: LM317BD2TG, LM317BD2TR4G, LM317D2T-TR, and LM317MDT-TR have MSL-1 (Unlimited shelf life). LM317KTTR has MSL-3 (168 Hours), requiring controlled storage conditions and bake-out procedures before reflow soldering if shelf life is exceeded.