LP3964ET-2.5 Equivalent & Substitute Parts

Part Overview

The LP3964ET-2.5 is a linear voltage regulator IC manufactured by Texas Instruments, designed to deliver a fixed 2.5V output at 800mA in a TO-220-5 package. This positive fixed output regulator includes integrated protection features for over-current, over-temperature, and short-circuit conditions, with an enable control feature for power management applications.

The LP3964ET-2.5 is classified as obsolete. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or maintenance requirements for systems utilizing this regulator.

Substiute Parts

LP3964ET-2.5

Texas InstrumentsIn Stock: 784LP3964ET-2.5 Datasheet

Current PartRFQ

TC1265-2.5VAT

Microchip TechnologyIn Stock: 1073TC1265-2.5VAT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LP3964ET-2.5 are identified based on the following critical parameters that determine functional equivalence:

• Fixed output voltage of 2.5V
• Output current capability of 800mA minimum
• TO-220-5 package configuration for mechanical and thermal compatibility
• Positive output configuration
• Single regulator output
• Operating temperature range of -40°C to 125°C
• Enable control feature for power management
• Over-current and over-temperature protection

The TC1265-2.5VAT from Microchip Technology meets these substitution criteria. While certain electrical characteristics differ (input voltage maximum, dropout voltage, and quiescent current), these differences do not prevent functional substitution when the application design accommodates the specified operating parameters of the substitute part.

Parameter Comparison

Engineering Selection Recommendations

The TC1265-2.5VAT is an active product from Microchip Technology and represents the primary substitute for the obsolete LP3964ET-2.5. Both parts are ROHS3 compliant and maintain identical output voltage and current specifications.

Selection of the TC1265-2.5VAT requires verification that the application design accommodates the following differences:

• Maximum input voltage is reduced from 7V to 6V
• Dropout voltage increases from 0.35V to 1.4V at full load
• Quiescent current is significantly lower (130 µA versus 9 mA)

The lower quiescent current of the TC1265-2.5VAT provides improved efficiency in standby or low-load conditions. The increased dropout voltage may require adjustment to input supply voltage margins in power-constrained applications. The reduced maximum input voltage necessitates confirmation that the application input supply does not exceed 6V.

Both parts provide identical mechanical compatibility through the TO-220-5 package and support the same operating temperature range. The TC1265-2.5VAT is recommended for new designs and ongoing production where supply continuity is required.

Frequently Asked Questions (FAQ)

Q: Can the TC1265-2.5VAT be used as a direct drop-in replacement for the LP3964ET-2.5?

A: The TC1265-2.5VAT is mechanically and functionally compatible through the TO-220-5 package and identical output specifications. However, the application design must accommodate the reduced maximum input voltage (6V versus 7V) and increased dropout voltage (1.4V versus 0.35V). Verification of input supply voltage margins is required before substitution.

Q: What are the key differences between these two regulators?

A: The primary differences are input voltage rating (7V maximum for LP3964ET-2.5 versus 6V for TC1265-2.5VAT), dropout voltage (0.35V versus 1.4V at 800mA), and quiescent current (9 mA versus 130 µA). Output voltage, output current, package, and operating temperature range are identical.

Q: Why is the quiescent current significantly lower in the TC1265-2.5VAT?

A: The TC1265-2.5VAT employs a different internal circuit design that reduces standby power consumption. This characteristic is beneficial for battery-powered or low-power applications where quiescent current directly impacts system efficiency.

Q: Are both parts RoHS compliant?

A: Yes, both the LP3964ET-2.5 and TC1265-2.5VAT are ROHS3 compliant and REACH unaffected.

Q: What is the impact of the increased dropout voltage on circuit design?

A: The increased dropout voltage (1.4V versus 0.35V) means the input supply must be at least 1.4V higher than the 2.5V output to maintain regulation at full load. Applications with tight input voltage margins may require input supply adjustment or thermal management review.

Q: Is the TC1265-2.5VAT available in production quantities?

A: Yes, the TC1265-2.5VAT is an active product from Microchip Technology with established supply chain availability, unlike the obsolete LP3964ET-2.5.