LP2985IM5-1.5/NOPB Equivalent & Substitute Parts

Part Overview

The LP2985IM5-1.5/NOPB is a linear voltage regulator IC from Texas Instruments designed for positive fixed 1.5V output at 150mA in a SOT-23-5 surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. The device provides regulated 1.5V output with integrated protection features including over-current, over-temperature, and short-circuit protection, suitable for low-power applications requiring stable voltage regulation.

Substiute Parts

LP2985IM5-1.5/NOPB

Texas InstrumentsIn Stock: 1123LP2985IM5-1.5/NOPB Datasheet

Current PartRFQ

LT1761ES5-1.5#TRMPBF

Analog Devices Inc.In Stock: 1387LT1761ES5-1.5#TRMPBF Datasheet

MFR RecommendedRFQ

LT1761ES5-1.5#TRPBF

Analog Devices Inc.In Stock: 1486LT1761ES5-1.5#TRPBF Datasheet

MFR RecommendedRFQ

LT1761IS5-1.5#TRMPBF

Analog Devices Inc.In Stock: 1181LT1761IS5-1.5#TRMPBF Datasheet

MFR RecommendedRFQ

LT1761IS5-1.5#TRPBF

Analog Devices Inc.In Stock: 1842LT1761IS5-1.5#TRPBF Datasheet

MFR RecommendedRFQ

SPX3819M5-L-1-5/TR

MaxLinear, Inc.In Stock: 22964SPX3819M5-L-1-5/TR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LP2985IM5-1.5/NOPB are selected based on the following critical parameters that determine functional compatibility:

Primary Substitution Criteria:

• Output voltage: 1.5V fixed
• Output configuration: Positive
• Package type: SOT-23-5 surface mount
• Input voltage rating: Minimum 16V maximum
• Operating temperature range: -40°C to 125°C
• Control features: Enable function
• Protection features: Over-current and over-temperature protection

Substitute Categories:

1. Direct Replacements (LT1761 Series) – Analog Devices Inc. LT1761ES5-1.5#TRMPBF, LT1761ES5-1.5#TRPBF, LT1761IS5-1.5#TRMPBF, and LT1761IS5-1.5#TRPBF meet all primary criteria with active product status and enhanced specifications (20V input maximum, 65dB PSRR at 120Hz, reverse polarity protection). Output current is 100mA, which is lower than the original 150mA but suitable for applications not requiring full current capacity.

2. Higher Current Alternative (SPX3819M5-L-1-5/TR) – MaxLinear Inc. SPX3819M5-L-1-5/TR provides 500mA output current in the same SOT-23-5 package with 1.5V fixed output and 16V input maximum. This part offers significantly higher current capacity for applications requiring greater load capability while maintaining the same package footprint and voltage specifications.

Parameter Comparison

Engineering Selection Recommendations

For Direct Functional Replacement: Select LT1761ES5-1.5#TRPBF or LT1761IS5-1.5#TRPBF when the application load current does not exceed 100mA. These Analog Devices parts are active products with ROHS3 compliance and enhanced input voltage rating (20V maximum). The LT1761 series offers improved PSRR performance (65dB at 120Hz) and reverse polarity protection compared to the original LP2985IM5-1.5/NOPB. Packaging variants (TRPBF for cut tape and digi-reel, TRMPBF for tape and reel) allow selection based on procurement requirements.

For Higher Current Applications: Select SPX3819M5-L-1-5/TR when the application requires output current up to 500mA while maintaining 1.5V fixed output in the same SOT-23-5 package footprint. This MaxLinear part is an active product with RoHS compliance and matches the original 16V input voltage maximum. The significantly higher current capacity makes this suitable for applications with greater load demands.

Compliance Considerations: All substitute parts maintain ROHS compliance and operate across the full -40°C to 125°C temperature range. The LT1761 series provides additional input voltage headroom (20V vs. 16V), which may improve system reliability in applications with higher input voltage transients.

Frequently Asked Questions (FAQ)

Q: Can the LT1761 series parts directly replace the LP2985IM5-1.5/NOPB in all applications?

A: The LT1761 series provides functional replacement for applications where output current does not exceed 100mA. The original LP2985IM5-1.5/NOPB is rated for 150mA output current. If your application requires the full 150mA capacity, the SPX3819M5-L-1-5/TR is the appropriate substitute. Both options maintain the same 1.5V output voltage, SOT-23-5 package, and operating temperature range.

Q: What is the difference between TRPBF and TRMPBF packaging designations for the LT1761 series?

A: TRPBF indicates cut tape and digi-reel packaging, while TRMPBF indicates tape and reel packaging. Both are surface mount variants of the same TSOT-23-5 package. Selection depends on your procurement and assembly process requirements. Electrical specifications are identical between these packaging variants.

Q: Why does the SPX3819M5-L-1-5/TR have higher output current than the original part?

A: The SPX3819M5-L-1-5/TR is designed with higher current capability (500mA) while maintaining the same SOT-23-5 package and 1.5V output voltage. This part is suitable for applications requiring greater load current. If your circuit only requires 150mA or less, either the LT1761 series or SPX3819 will function correctly, with the SPX3819 providing additional current margin.

Q: Are there compatibility concerns with the TSOT-23-5 package variant used by the LT1761 series?

A: The TSOT-23-5 (thin SOT-23-5) is mechanically and electrically compatible with standard SOT-23-5 packages. Both packages have identical pin configurations and footprints suitable for standard SOT-23-5 PCB layouts. The TSOT-23-5 designation indicates a thinner package profile, which does not affect electrical performance or board-level compatibility.

Q: What protection features should I verify when substituting these parts?

A: All substitute parts include over-current and over-temperature protection. The LT1761 series and SPX3819M5-L-1-5/TR additionally provide reverse polarity protection, which the original LP2985IM5-1.5/NOPB does not include. This additional protection in substitute parts enhances system robustness without requiring circuit modifications.

Q: Can I use the SPX3819M5-L-1-5/TR in place of the LT1761 series?

A: Yes, the SPX3819M5-L-1-5/TR is functionally compatible with the LT1761 series for applications requiring 1.5V output in SOT-23-5 package. The SPX3819 provides higher output current (500mA) and lower quiescent current (8µA vs. not specified for LT1761). Both parts maintain the same output voltage, package, and operating temperature range. Selection depends on your specific current requirements and procurement availability.