REG103FA-3.3/500 Equivalent & Substitute Parts

Part Overview

The REG103FA-3.3/500 is a linear voltage regulator IC from Texas Instruments designed for positive fixed 3.3V output at 500mA in a TO-263 (DDPAK-5) surface mount package. This device is classified as Not For New Designs, indicating it has reached end-of-life status. Finding equivalent or substitute parts is necessary for ongoing production support, maintenance applications, and inventory management where the original part is no longer readily available or recommended for new circuit designs.

Substiute Parts

REG103FA-3.3/500

Texas InstrumentsIn Stock: 911REG103FA-3.3/500 Datasheet

Current PartRFQ

REG103FA-3.3KTTT

Texas InstrumentsIn Stock: 2028REG103FA-3.3KTTT Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the REG103FA-3.3/500 is determined by strict equivalence across the following critical parameters:

• Output voltage specification: 3.3V fixed
• Output current capability: 500mA minimum
• Maximum input voltage: 15V or greater
• Voltage dropout: 0.28V @ 500mA or lower
• Package compatibility: TO-263 (DDPAK-5) surface mount
• Operating temperature range: -40°C to 85°C minimum
• Protection features: Over Current and Over Temperature protection required
• Control features: Enable function required
• Regulatory compliance: ROHS3 Compliant

The substitute part REG103FA-3.3KTTT meets all these criteria and is manufactured by the same supplier (Texas Instruments), ensuring functional and mechanical compatibility.

Parameter Comparison

Engineering Selection Recommendations

The REG103FA-3.3KTTT is a direct parametric equivalent to the REG103FA-3.3/500. Both parts share identical electrical specifications, thermal performance, and package configuration. The primary distinction is product lifecycle status: the original part is classified as Not For New Designs, while the substitute is designated Last Time Buy, indicating limited availability.

For applications currently using REG103FA-3.3/500, the REG103FA-3.3KTTT provides functional continuity with no circuit modifications required. Both parts maintain ROHS3 compliance and identical regulatory certifications (REACH Unaffected, ECCN EAR99).

Selection between these parts should be based on inventory availability and project timeline requirements. The substitute part currently has higher stock availability (2000 Pcs vs. 830 Pcs), which may be relevant for production planning.

Frequently Asked Questions (FAQ)

Q: Can REG103FA-3.3KTTT be used as a direct replacement for REG103FA-3.3/500?

A: Yes. Both parts are parametrically identical across all electrical and thermal specifications. No circuit modifications, PCB layout changes, or firmware updates are required. The TO-263 (DDPAK-5) package footprint is identical, allowing direct board-level substitution.

Q: What is the difference between these two part numbers?

A: The parts are electrically and mechanically equivalent. The difference lies in product lifecycle designation and packaging configuration. REG103FA-3.3/500 uses Tape & Reel packaging and is marked Not For New Designs. REG103FA-3.3KTTT also uses Tape & Reel packaging but carries Last Time Buy status, indicating it remains available for a limited period.

Q: Are there any compliance or certification differences?

A: No. Both parts maintain identical compliance certifications: ROHS3 Compliant, REACH Unaffected, and ECCN EAR99. Moisture Sensitivity Level (MSL) is 2 (1 Year) for both parts.

Q: What is the package compatibility?

A: Both parts use the TO-263-6 package, also designated D2PAK (5 Leads + Tab) or TO-263BA. This is a surface mount package with identical pin configuration, spacing, and thermal characteristics. PCB footprints are fully compatible.

Q: Which part should be selected for new inventory procurement?

A: REG103FA-3.3KTTT is the appropriate choice for ongoing procurement. It maintains all functional equivalence while offering higher current stock availability. The original part's Not For New Designs status indicates it should not be selected for new applications or long-term inventory builds.