REG103FA-AKTTT Equivalent & Substitute Parts

Part Overview

The REG103FA-AKTTT is a linear voltage regulator IC from Texas Instruments designed for positive adjustable output applications. This device delivers 500mA output current in a TO-263 (DDPAK-5) surface mount package and operates across an input voltage range of up to 15V with adjustable output 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-AKTTT

Texas InstrumentsIn Stock: 2299REG103FA-AKTTT Datasheet

Current PartRFQ

TPS7B8601QKVURQ1

Texas InstrumentsIn Stock: 3504TPS7B8601QKVURQ1 Datasheet

MFR RecommendedRFQ

REG103FA-A/500

Texas InstrumentsIn Stock: 1527REG103FA-A/500 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

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

Parametric Equivalence Criteria:

• Output configuration (Positive Adjustable)
• Number of regulators (1)
• Output current capability (500mA minimum)
• Adjustable output voltage range (must encompass or exceed 1.295V to 5.5V)
• Surface mount package compatibility
• Dropout voltage performance at rated current

Substitutes are grouped into two categories:

1. Parametric Equivalent (REG103FA-A/500): Identical electrical specifications and package type, differing only in product status and inventory availability.

2. Functional Substitute with Enhanced Specifications (TPS7B8601QKVURQ1): Meets or exceeds all critical performance parameters with different package type (TO-252-5), higher input voltage rating, lower quiescent current, and active product status.

Parameter Comparison

Engineering Selection Recommendations

REG103FA-A/500 is the direct parametric equivalent with identical electrical performance and package type. Both parts share Last Time Buy status, making this option suitable only for immediate replacement needs where existing inventory is depleted. This part maintains full pin and footprint compatibility.

TPS7B8601QKVURQ1 is recommended for new designs and long-term supply continuity. This part is Active status and carries AEC-Q100 automotive qualification. It provides enhanced specifications including higher input voltage tolerance (40V vs. 15V), significantly lower quiescent current (26 µA vs. 0.7 mA), and extended operating temperature range (-40°C to 150°C). The package differs (TO-252-5 vs. TO-263), requiring PCB layout modification. The higher dropout voltage (0.570V vs. 0.28V) must be evaluated against application thermal and efficiency requirements.

Frequently Asked Questions (FAQ)

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

A: Yes. REG103FA-A/500 is a parametric equivalent with identical electrical specifications, output current, voltage ranges, dropout voltage, and TO-263 package. Pin-for-pin and footprint compatibility is maintained. Both parts are Last Time Buy status.

Q: What are the key differences between REG103FA-AKTTT and TPS7B8601QKVURQ1?

A: The primary differences are package type (TO-263 vs. TO-252-5), product status (Last Time Buy vs. Active), input voltage rating (15V vs. 40V), quiescent current (0.7 mA vs. 26 µA), and operating temperature range (-40°C to 85°C vs. -40°C to 150°C). Dropout voltage is higher in the TPS7B8601QKVURQ1 (0.570V vs. 0.28V). The TPS7B8601QKVURQ1 includes automotive qualification (AEC-Q100).

Q: Does package change from TO-263 to TO-252-5 affect thermal performance?

A: Both packages are surface mount with thermal tabs. Thermal performance depends on PCB layout, copper area, and thermal vias. Specific thermal analysis is required for your application to determine if the package change impacts heat dissipation adequacy.

Q: Is TPS7B8601QKVURQ1 suitable for automotive applications?

A: Yes. TPS7B8601QKVURQ1 carries AEC-Q100 automotive qualification. REG103FA-AKTTT and REG103FA-A/500 do not have automotive qualification.

Q: What is the impact of higher dropout voltage in TPS7B8601QKVURQ1?

A: The TPS7B8601QKVURQ1 has 0.570V dropout at 500mA compared to 0.28V in REG103FA-AKTTT. This means higher input voltage is required to maintain regulation at full load. For applications with tight input voltage margins, verify that the higher dropout voltage does not violate system requirements.

Q: Can I use TPS7B8601QKVURQ1 in existing PCBs designed for REG103FA-AKTTT?

A: No. The package types differ (TO-252-5 vs. TO-263), requiring PCB layout redesign. Pin assignments must be verified before layout modification.