LP3856ET-3.3 Equivalent & Substitute Parts

Part Overview

The LP3856ET-3.3 is a linear voltage regulator IC from Texas Instruments, delivering a fixed 3.3V output at 3A in a TO-220-5 package. This part is classified as obsolete, making equivalent substitutes necessary for new designs and ongoing production requirements. The regulator provides positive fixed output configuration with integrated protection features including over-current, over-temperature, and short-circuit protection, suitable for applications requiring stable 3.3V power delivery in through-hole mounting configurations.

Substiute Parts

LP3856ET-3.3

Texas InstrumentsIn Stock: 2327LP3856ET-3.3 Datasheet

Current PartRFQ

LP3856ET-3.3/NOPB

Texas InstrumentsIn Stock: 1151LP3856ET-3.3/NOPB Datasheet

DirectRFQ

LP3853ET-3.3/NOPB

Texas InstrumentsIn Stock: 1164LP3853ET-3.3/NOPB Datasheet

Parametric EquivalentRFQ

LT1764AET-3.3#PBF

Analog Devices Inc.In Stock: 1379LT1764AET-3.3#PBF Datasheet

MFR RecommendedRFQ

LT1764ET-3.3#PBF

Analog Devices Inc.In Stock: 919LT1764ET-3.3#PBF Datasheet

MFR RecommendedRFQ

LP3876ET-3.3/NOPB

National SemiconductorIn Stock: 2190LP3876ET-3.3/NOPB Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LP3856ET-3.3 is determined by the following critical parameters: fixed 3.3V output voltage, 3A output current capability, TO-220-5 package compatibility, through-hole mounting, and operating temperature range of -40°C to 125°C. All substitute parts must maintain these core electrical and mechanical specifications to ensure functional equivalence in existing circuit designs.

The substitute parts are grouped into three categories:

Direct Manufacturer Equivalent: LP3856ET-3.3/NOPB maintains identical electrical specifications and differs only in packaging format (Tube vs. unspecified original packaging) and product status (Active vs. Obsolete).

Parametric Equivalents: LP3853ET-3.3/NOPB and LP3876ET-3.3/NOPB deliver the same output voltage, current, and package configuration. Variations exist in quiescent current, dropout voltage, and PSRR specifications, but these remain within acceptable tolerances for most applications.

Manufacturer Recommended Alternatives: LT1764AET-3.3#PBF and LT1764ET-3.3#PBF from Analog Devices Inc. provide superior performance characteristics including higher maximum input voltage (20V vs. 7V), lower quiescent current (1.5 mA vs. 4 mA), and enhanced protection features (Reverse Polarity protection included).

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement: LP3856ET-3.3/NOPB is the primary choice, offering identical electrical performance to the obsolete LP3856ET-3.3 while maintaining Active product status and ROHS3 compliance. This part requires no circuit modifications and provides the most straightforward transition path.

For Active Production: LP3853ET-3.3/NOPB serves as an alternative Texas Instruments source with equivalent specifications and Active status. Both LP3856ET-3.3/NOPB and LP3853ET-3.3/NOPB are suitable for new designs requiring 3.3V regulation at 3A with 7V maximum input voltage.

For Enhanced Performance: LT1764AET-3.3#PBF and LT1764ET-3.3#PBF from Analog Devices Inc. offer superior specifications including 20V maximum input voltage, lower quiescent current (1.5 mA), and reverse polarity protection. These parts are recommended for applications with higher input voltage requirements or where reduced power consumption is beneficial. Both variants are ROHS3 compliant and Active.

For Cost-Optimized Applications: LP3876ET-3.3/NOPB from National Semiconductor maintains core specifications but exhibits higher dropout voltage (1.2V vs. 0.6V) and slightly elevated quiescent current (5 mA vs. 4 mA). This part is suitable for applications where these performance differences are acceptable and cost optimization is prioritized.

Frequently Asked Questions (FAQ)

Q: Can LP3856ET-3.3/NOPB directly replace the obsolete LP3856ET-3.3?

A: Yes. LP3856ET-3.3/NOPB is electrically and mechanically identical to the original part, differing only in packaging format and product status. No circuit modifications are required.

Q: What is the primary difference between Texas Instruments and Analog Devices substitutes?

A: Texas Instruments substitutes (LP3856ET-3.3/NOPB, LP3853ET-3.3/NOPB) maintain the original 7V maximum input voltage specification. Analog Devices LT1764 series parts support 20V maximum input voltage, lower quiescent current, and reverse polarity protection, making them suitable for applications with higher input voltage requirements.

Q: Are all substitute parts available in the same TO-220-5 package?

A: Yes. All listed substitute parts use TO-220-5 Formed Leads package with through-hole mounting, ensuring mechanical compatibility with existing PCB designs.

Q: Which substitute offers the best power efficiency?

A: LT1764AET-3.3#PBF and LT1764ET-3.3#PBF provide the lowest quiescent current at 1.5 mA compared to 4-5 mA in other options, resulting in reduced standby power consumption.

Q: Is RoHS compliance a factor in selecting a substitute?

A: Yes. LP3856ET-3.3/NOPB, LP3853ET-3.3/NOPB, LT1764AET-3.3#PBF, and LT1764ET-3.3#PBF are all ROHS3 compliant. The original LP3856ET-3.3 is RoHS non-compliant. For applications requiring RoHS compliance, select from the compliant alternatives.

Q: What is the significance of dropout voltage differences?

A: Dropout voltage determines the minimum input-to-output voltage differential required for regulation. LP3876ET-3.3/NOPB has 1.2V dropout versus 0.6V in other options. In applications with tight input voltage margins, lower dropout voltage parts (0.6V or 0.66V) are preferred.

Q: Can LT1764 parts handle higher input voltages than the original LP3856ET-3.3?

A: Yes. LT1764AET-3.3#PBF and LT1764ET-3.3#PBF support 20V maximum input voltage compared to 7V for the LP3856ET-3.3. This makes them suitable for applications with higher supply voltages, though circuit design must accommodate this capability.