REG103FA-A/500 Equivalent & Substitute Parts

Part Overview

The REG103FA-A/500 is a linear voltage regulator IC from Texas Instruments designed for positive adjustable output applications. This Surface Mount device in TO-263 (DDPAK-5) packaging delivers 500mA output current with adjustable voltage output ranging from 1.295V to 5.5V. The part is classified as Last Time Buy, indicating end-of-life status. Identifying equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain reliability for applications currently using this regulator.

Substiute Parts

REG103FA-A/500

Texas InstrumentsIn Stock: 1527REG103FA-A/500 Datasheet

Current PartRFQ

TPS7B8601QKVURQ1

Texas InstrumentsIn Stock: 3504TPS7B8601QKVURQ1 Datasheet

MFR RecommendedRFQ

REG103FA-AKTTT

Texas InstrumentsIn Stock: 2299REG103FA-AKTTT Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the REG103FA-A/500 are identified based on the following critical parameters that determine functional compatibility:

Parametric Equivalence Criteria:

• Output Configuration: Positive
• Output Type: Adjustable
• Number of Regulators: 1
• Current - Output: 500mA minimum
• Voltage - Output range capability: Must support 1.295V to 5.5V
• Mounting Type: Surface Mount
• Package compatibility: TO-263 or equivalent pinout

Substitution Categories:

1. Parametric Equivalent – REG103FA-AKTTT: Identical electrical specifications and package, same TO-263 (DDPAK-5) form factor, same base product series (REG103)

2. Manufacturer Recommended Substitute – TPS7B8601QKVURQ1: Enhanced specifications with broader input voltage range (40V vs 15V), wider output voltage range (1.2V to 18V), superior quiescent current (26µA vs 0.7mA), and automotive-grade qualification (AEC-Q100). Different package form factor (TO-252-5) requires PCB layout modification.

Parameter Comparison

Engineering Selection Recommendations

REG103FA-AKTTT is the direct parametric equivalent for drop-in replacement applications. This part maintains identical electrical specifications, package form factor, and pinout compatibility with the REG103FA-A/500. Both parts share Last Time Buy status, indicating similar lifecycle positioning. Selection of this substitute requires no design modifications and provides immediate compatibility.

TPS7B8601QKVURQ1 is the manufacturer-recommended substitute for new designs or applications requiring extended product lifecycle. This part offers Active product status, ensuring long-term availability and supply chain stability. The TPS7B8601QKVURQ1 provides enhanced specifications including higher input voltage tolerance (40V), broader output voltage range (1.2V to 18V), significantly lower quiescent current (26µA), and automotive-grade qualification (AEC-Q100). Implementation requires PCB layout modification due to different package form factor (TO-252-5 vs TO-263-6). The increased dropout voltage (0.570V vs 0.28V) must be evaluated for thermal and efficiency impact in the target application.

Frequently Asked Questions (FAQ)

Q: Can REG103FA-AKTTT be used as a direct replacement for REG103FA-A/500?

A: Yes. REG103FA-AKTTT is a parametric equivalent with identical electrical specifications, output voltage range (1.295V to 5.5V), output current (500mA), dropout voltage (0.28V @ 500mA), and package form factor (TO-263-6, D2PAK). No design modifications are required for drop-in replacement.

Q: What are the key differences between REG103FA-A/500 and TPS7B8601QKVURQ1?

A: The primary differences are: (1) Package form factor – TPS7B8601QKVURQ1 uses TO-252-5 instead of TO-263-6, requiring PCB layout changes; (2) Input voltage range – TPS7B8601QKVURQ1 supports up to 40V vs 15V; (3) Output voltage range – TPS7B8601QKVURQ1 supports 1.2V to 18V vs 1.295V to 5.5V; (4) Quiescent current – TPS7B8601QKVURQ1 draws 26µA vs 0.7mA; (5) Dropout voltage – TPS7B8601QKVURQ1 has 0.570V vs 0.28V at 500mA; (6) Product status – TPS7B8601QKVURQ1 is Active vs Last Time Buy; (7) Qualification – TPS7B8601QKVURQ1 is AEC-Q100 automotive-grade.

Q: Is TPS7B8601QKVURQ1 suitable for applications currently using REG103FA-A/500?

A: Functional compatibility depends on application requirements. If the design operates within the TPS7B8601QKVURQ1 specifications (input voltage ≤40V, output voltage within 1.2V to 18V range, and thermal performance acceptable with 0.570V dropout), the part is suitable. PCB layout modification is mandatory due to different package form factor. Verify that the increased dropout voltage does not compromise thermal margins or efficiency requirements.

Q: Why does REG103FA-A/500 have Last Time Buy status?

A: Last Time Buy status indicates the manufacturer has discontinued or is discontinuing production. REG103FA-AKTTT shares this status. For long-term supply chain security, TPS7B8601QKVURQ1 with Active status is recommended for new designs.

Q: Can both TO-263-6 and TO-252-5 packages be used interchangeably on the same PCB?

A: No. TO-263-6 (D2PAK) and TO-252-5 (DPAK) have different physical dimensions and pinout layouts. PCB footprint redesign is required to accommodate TPS7B8601QKVURQ1 in TO-252-5 package.

Q: What is the impact of higher quiescent current in REG103FA-A/500 compared to TPS7B8601QKVURQ1?

A: REG103FA-A/500 draws 0.7mA quiescent current vs 26µA for TPS7B8601QKVURQ1. In battery-powered or low-power standby applications, this 27x difference may be significant. TPS7B8601QKVURQ1 provides superior efficiency in low-load conditions.