REG103FA-5/500 Equivalent & Substitute Parts

Part Overview

The REG103FA-5/500 is a linear voltage regulator IC from Texas Instruments, classified as a Power Management (PMIC) component. It delivers a fixed positive 5V output at 500mA with a maximum input voltage of 15V and a dropout voltage of 0.28V at full load. The device is housed in a TO-263 (DDPAK-5) surface mount package and includes integrated over-current and over-temperature protection features.

The REG103FA-5/500 is currently marked as Obsolete, making it necessary to identify equivalent and substitute parts for new designs or production continuity. Alternative components with matching or enhanced electrical characteristics are available from the same manufacturer.

Substiute Parts

REG103FA-5/500

Texas InstrumentsIn Stock: 1060REG103FA-5/500 Datasheet

Current PartRFQ

REG104FA-5/500

Texas InstrumentsIn Stock: 2420REG104FA-5/500 Datasheet

DirectRFQ

REG103FA-5KTTT

Texas InstrumentsIn Stock: 1237REG103FA-5KTTT Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the REG103FA-5/500 are identified based on the following critical parameters that determine functional compatibility:

• Fixed output voltage of 5V
• Output current capability (500mA minimum)
• Maximum input voltage of 15V
• TO-263 (DDPAK-5) package compatibility
• Integrated over-current and over-temperature protection
• Enable control feature
• Operating temperature range of -40°C ~ 85°C

Two substitute parts meet these criteria with variations in output current capacity and product status:

REG103FA-5KTTT is a parametric equivalent with identical electrical specifications but different packaging format (Tape & Reel instead of Cut Tape).

REG104FA-5/500 is a direct manufacturer substitute with enhanced output current capability (1A versus 500mA), maintaining all other core electrical and mechanical parameters.

Parameter Comparison

Engineering Selection Recommendations

REG103FA-5KTTT is suitable for direct replacement in applications requiring 500mA output current. This part maintains identical electrical performance to the REG103FA-5/500 and differs only in packaging format (Tape & Reel versus Cut Tape). Both parts carry Last Time Buy status, indicating limited future availability. ROHS3 compliance and MSL 2 rating are maintained.

REG104FA-5/500 is appropriate for applications where output current demand may reach 1A or where design margin for current capacity is required. The increased output current rating (1A versus 500mA) results in a higher dropout voltage specification (0.58V @ 1A versus 0.28V @ 500mA). This part also carries Last Time Buy status and maintains full ROHS3 compliance and MSL 2 rating. The identical package footprint (TO-263-6) ensures mechanical compatibility with existing PCB designs.

Selection between these substitutes depends on the actual current requirements of the application. If the design draws 500mA or less, either substitute is functionally equivalent. If current demand approaches or exceeds 500mA, the REG104FA-5/500 provides additional headroom.

Frequently Asked Questions (FAQ)

Q: Can REG103FA-5KTTT be used as a direct replacement for REG103FA-5/500?

A: Yes. REG103FA-5KTTT is a parametric equivalent with identical electrical specifications. The only difference is packaging format: REG103FA-5/500 is supplied in Cut Tape format, while REG103FA-5KTTT is supplied in Tape & Reel format. Both deliver 5V at 500mA with 0.28V dropout voltage and are housed in the same TO-263-6 package.

Q: What is the key difference between REG104FA-5/500 and REG103FA-5/500?

A: The primary difference is output current capability. REG104FA-5/500 delivers 1A, while REG103FA-5/500 delivers 500mA. This results in a higher dropout voltage for the REG104FA-5/500 (0.58V @ 1A versus 0.28V @ 500mA). All other electrical parameters, including output voltage, input voltage rating, protection features, and package type, remain identical.

Q: Are both substitute parts pin-compatible with the original REG103FA-5/500?

A: Yes. Both REG103FA-5KTTT and REG104FA-5/500 use the identical TO-263-6 (DDPAK-5) package with the same pinout and footprint. PCB layout modifications are not required for either substitute.

Q: What is the significance of the Last Time Buy status on the substitute parts?

A: Last Time Buy status indicates that these parts are in their final production phase and will not be manufactured after a specified date. Inventory is available but will eventually be depleted. For long-term production requirements, alternative solutions from current product lines should be evaluated.

Q: Are both substitute parts RoHS compliant?

A: Yes. Both REG103FA-5KTTT and REG104FA-5/500 are ROHS3 compliant and carry MSL 2 (1 Year) moisture sensitivity rating, matching the compliance profile of the original REG103FA-5/500.

Q: Which substitute should be selected for a new design?

A: Selection depends on current requirements. For applications drawing 500mA or less, either substitute is suitable. REG103FA-5KTTT provides an exact electrical match. For applications requiring higher current capacity or design margin, REG104FA-5/500 is appropriate. Both parts are available in inventory and carry equivalent compliance certifications.