REG103FA-2.5 Equivalent & Substitute Parts

Part Overview

The REG103FA-2.5 is a linear voltage regulator IC from Texas Instruments, delivering a fixed 2.5V output at 500mA in a TO-263 (DDPAK-5) surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production support. The regulator features integrated over-current and over-temperature protection with an enable control function, suitable for applications requiring stable low-voltage power delivery in compact form factors.

Substiute Parts

REG103FA-2.5

Texas InstrumentsIn Stock: 2200REG103FA-2.5 Datasheet

Current PartRFQ

REG103FA-2.5KTTT

Texas InstrumentsIn Stock: 1397REG103FA-2.5KTTT Datasheet

DirectRFQ

REG104FA-2.5KTTT

Texas InstrumentsIn Stock: 1323REG104FA-2.5KTTT Datasheet

DirectRFQ

TC1263-2.5VETTR

Microchip TechnologyIn Stock: 818TC1263-2.5VETTR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the REG103FA-2.5 is determined by the following critical parameters: fixed 2.5V output voltage, TO-263 (DDPAK-5) package compatibility, surface mount mounting type, and functional equivalence in linear voltage regulation. The substitute parts are grouped into two categories:

Category 1: Direct Electrical Equivalents (Same Output Current) Parts maintaining 500mA output current with identical 2.5V fixed output and TO-263 packaging. These parts differ primarily in packaging format (Tape & Reel vs. Tube) and product status (Active vs. Obsolete).

Category 2: Higher Current Capability (Upgraded Output Current) Parts with 1A output current capability, providing increased current headroom while maintaining 2.5V fixed output and TO-263 packaging. These are suitable for applications requiring higher current delivery.

Category 3: Alternative Manufacturer (Cross-Manufacturer Equivalent) Parts from Microchip Technology with equivalent functional specifications, 500mA output current, and TO-263 packaging, offering alternative sourcing options.

Parameter Comparison

Engineering Selection Recommendations

REG103FA-2.5KTTT is the primary direct substitute for the obsolete REG103FA-2.5. Both parts are electrically and mechanically identical, with the key difference being product status (Active vs. Obsolete) and packaging format (Tape & Reel vs. Tube). The REG103FA-2.5KTTT carries ROHS3 compliance, addressing regulatory requirements for new designs. This part is recommended for direct replacement in existing applications without circuit modification.

REG104FA-2.5KTTT provides increased output current capability (1A vs. 500mA) while maintaining the same 2.5V output voltage and TO-263 package. This part is suitable for applications requiring higher current delivery or designs with future current scaling requirements. The part carries ROHS3 compliance but is classified as Last Time Buy, indicating limited future availability.

TC1263-2.5VETTR from Microchip Technology offers an alternative sourcing option with equivalent 500mA output current and 2.5V fixed output. This part features lower quiescent current (130 µA vs. 0.7 mA), extended operating temperature range (-40°C ~ 125°C vs. -40°C ~ 85°C), and superior moisture sensitivity rating (MSL 1 vs. MSL 2). However, the maximum input voltage is limited to 6V compared to 15V for Texas Instruments parts, and dropout voltage is higher (0.65V vs. 0.28V). This part is suitable for applications with input voltages below 6V and where lower quiescent current is beneficial.

Frequently Asked Questions (FAQ)

Q: Can REG103FA-2.5KTTT be used as a direct replacement for REG103FA-2.5?

A: Yes. Both parts are electrically and mechanically identical linear voltage regulators with 2.5V fixed output, 500mA output current, and TO-263 (DDPAK-5) packaging. The primary difference is product status and packaging format. REG103FA-2.5KTTT is the active production equivalent.

Q: What is the difference between REG103FA-2.5KTTT and REG104FA-2.5KTTT?

A: The REG104FA-2.5KTTT provides double the output current (1A vs. 500mA) while maintaining the same 2.5V output voltage and TO-263 package. Both parts are suitable for 2.5V applications, but REG104FA-2.5KTTT is selected when higher current delivery is required. The REG104FA-2.5KTTT is classified as Last Time Buy, indicating limited future availability.

Q: Can TC1263-2.5VETTR replace REG103FA-2.5 in all applications?

A: TC1263-2.5VETTR is functionally equivalent for 2.5V, 500mA applications in the same TO-263 package. However, the maximum input voltage is limited to 6V (vs. 15V for REG103FA-2.5), and dropout voltage is higher (0.65V vs. 0.28V). Verify input voltage requirements before substitution. The part is suitable for applications with input voltages below 6V.

Q: What are the packaging format differences between these parts?

A: REG103FA-2.5 is supplied in Tube packaging, while REG103FA-2.5KTTT, REG104FA-2.5KTTT, and TC1263-2.5VETTR are supplied in Tape & Reel (TR) format. Both formats are compatible with the same TO-263 (DDPAK-5) package footprint. Tape & Reel format is standard for automated assembly processes.

Q: Why does TC1263-2.5VETTR have lower quiescent current?

A: The TC1263-2.5VETTR from Microchip Technology is designed with lower quiescent current (130 µA vs. 0.7 mA), which reduces standby power consumption. This characteristic makes it suitable for battery-powered or low-power applications where quiescent current is a critical design parameter.

Q: Are all substitute parts RoHS compliant?

A: REG103FA-2.5KTTT, REG104FA-2.5KTTT, and TC1263-2.5VETTR are all ROHS3 compliant. The original REG103FA-2.5 is RoHS non-compliant. For new designs subject to RoHS regulations, use one of the compliant substitute parts.

Q: What is the MSL rating and why does it matter?

A: MSL (Moisture Sensitivity Level) indicates the component's sensitivity to moisture during storage and handling. REG103FA-2.5, REG103FA-2.5KTTT, and REG104FA-2.5KTTT have MSL 2 (1 Year shelf life), while TC1263-2.5VETTR has MSL 1 (Unlimited shelf life). Lower MSL ratings provide longer storage windows and reduced risk of moisture-related failures.