LP2957AIT Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LP2957AIT is a linear voltage regulator IC from Texas Instruments designed for positive fixed 5V output at 250mA in a TO-220-5 through-hole package. This device is classified as obsolete product status. Due to its obsolete classification, identifying equivalent and substitute parts is necessary to maintain design continuity and ensure component availability for new production runs and field replacements.

Substiute Parts

LP2957AIT

Texas InstrumentsIn Stock: 1078LP2957AIT Datasheet

Current PartRFQ

LP2957AIT/NOPB

Texas InstrumentsIn Stock: 1497LP2957AIT/NOPB Datasheet

DirectRFQ

LP2954AIS/NOPB

Texas InstrumentsIn Stock: 1465LP2954AIS/NOPB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LP2957AIT are identified based on the following critical parameters that determine functional equivalence:

Electrical Parameters (Must Match):

• Output voltage: 5V fixed
• Maximum input voltage: 30V
• Output current capability: 250mA
• Voltage dropout: 0.8V @ 250mA
• Control features: Enable function
• Protection features: Over Current, Over Temperature, Reverse Polarity
• Operating temperature range: -40°C ~ 125°C

Mechanical Parameters (Package Considerations):

• Mounting type (through-hole vs. surface mount)
• Package designation and pin configuration

Substitutes are grouped into two categories: direct package equivalents and alternative package solutions with identical electrical specifications.

Parameter Comparison

Engineering Selection Recommendations

LP2957AIT/NOPB is the direct equivalent substitute for LP2957AIT. Both parts share identical electrical specifications, control features, and protection characteristics. The primary difference is product status: LP2957AIT/NOPB is active and carries ROHS3 compliance certification, whereas the original LP2957AIT is obsolete and RoHS non-compliant. This part maintains the same TO-220-5 through-hole package, requiring no PCB layout modifications. Selection of LP2957AIT/NOPB is appropriate for designs requiring direct form-fit-function replacement with improved regulatory compliance.

LP2954AIS/NOPB is a manufacturer-recommended alternative that provides identical electrical performance with a different package form factor. This part uses a TO-263 (DDPAK-3) surface-mount package instead of through-hole mounting. The quiescent current is lower at 150 µA compared to 200 µA. This substitute is suitable for new designs or redesigns where surface-mount assembly is preferred. PCB layout and assembly process modifications are required. The MSL rating of 3 (168 Hours) requires controlled moisture handling during storage and assembly compared to the unlimited MSL of through-hole variants.

Both substitute parts carry ROHS3 compliance and REACH Unaffected status, meeting current regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can LP2957AIT/NOPB be used as a direct replacement for LP2957AIT?

A: Yes. LP2957AIT/NOPB is electrically and mechanically identical to LP2957AIT. Both use the TO-220-5 through-hole package with the same pin configuration. No circuit modifications or PCB layout changes are required. The primary advantage is that LP2957AIT/NOPB is an active product with ROHS3 compliance.

Q: What is the difference between LP2957AIT/NOPB and LP2954AIS/NOPB?

A: The primary difference is package type. LP2957AIT/NOPB uses a TO-220-5 through-hole package, while LP2954AIS/NOPB uses a TO-263 (DDPAK-3) surface-mount package. Electrically, both deliver 5V at 250mA with identical dropout voltage and protection features. The LP2954AIS/NOPB has a lower quiescent current of 150 µA versus 200 µA. PCB redesign is necessary to use LP2954AIS/NOPB.

Q: Can LP2954AIS/NOPB be used in a through-hole design?

A: No. LP2954AIS/NOPB is a surface-mount component in TO-263 package format. It cannot be directly installed in a PCB designed for through-hole TO-220-5 components. A PCB redesign and assembly process change to surface-mount technology would be required.

Q: Are there any compliance differences between these parts?

A: Yes. LP2957AIT is RoHS non-compliant, while both LP2957AIT/NOPB and LP2954AIS/NOPB are ROHS3 compliant. All three parts are REACH Unaffected. For new designs or applications with regulatory requirements, the ROHS3-compliant variants are recommended.

Q: What is the moisture sensitivity consideration for LP2954AIS/NOPB?

A: LP2954AIS/NOPB has an MSL rating of 3 (168 Hours), meaning the component must be used within 168 hours of opening the moisture barrier bag. LP2957AIT and LP2957AIT/NOPB have MSL 1 (Unlimited), requiring no special moisture handling. For high-volume production, the MSL 3 rating of LP2954AIS/NOPB requires controlled storage and assembly environment management.

Q: What are the key electrical parameters that make these parts substitutable?

A: The critical parameters are: 5V fixed output voltage, 250mA output current, 30V maximum input voltage, 0.8V maximum dropout voltage at 250mA, Enable control feature, and identical protection features (Over Current, Over Temperature, Reverse Polarity). All three parts meet these specifications across the -40°C to 125°C operating temperature range.