LMS1587IT-ADJ Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LMS1587IT-ADJ is a linear voltage regulator IC from Texas Instruments designed for positive adjustable output applications. It delivers 3A output current in a TO-220-3 package and operates across an input voltage range up to 13V with adjustable output from 1.25V to 11.7V. The device is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support, production continuity, and system maintenance.

Substiute Parts

LMS1587IT-ADJ

Texas InstrumentsIn Stock: 2283LMS1587IT-ADJ Datasheet

Current PartRFQ

LD1085V

STMicroelectronicsIn Stock: 1215LD1085V Datasheet

MFR RecommendedRFQ

LT1587CT#PBF

Linear TechnologyIn Stock: 1284LT1587CT#PBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LMS1587IT-ADJ are identified based on strict alignment with the following electrical and mechanical parameters:

• Output configuration (positive adjustable)
• Output current capability (3A)
• Package type (TO-220-3)
• Adjustable output voltage range (minimum 1.25V)
• Protection features (over current, over temperature)
• Mounting type (through hole)
• Regulatory compliance (ROHS3, REACH Unaffected)

The identified substitutes maintain functional equivalence within their specified input voltage and output voltage ranges. Substitution validity depends on the application's specific voltage requirements and thermal operating conditions.

Parameter Comparison

Engineering Selection Recommendations

LD1085V (STMicroelectronics) is an active product with extended input voltage capability (30V maximum) and maintains identical output current (3A), adjustable output range (1.25V minimum), and operating temperature range (-40°C ~ 125°C). This substitute is suitable for applications requiring higher input voltage tolerance. Both devices are ROHS3 compliant and feature equivalent PSRR performance.

LT1587CT#PBF (Linear Technology) is an active product with identical dropout voltage (1.3V @ 3A) and includes short circuit protection in addition to over current and over temperature protection. However, this substitute has a reduced maximum input voltage (7V) and maximum output voltage (5.5V), and a narrower operating temperature range (0°C ~ 125°C). This substitute is applicable only to applications with input voltages not exceeding 7V and output requirements within 5.5V.

Selection between substitutes must account for the specific input voltage and output voltage requirements of the target application. Both active substitutes provide through-hole TO-220-3 mounting compatibility and maintain the 3A output current specification.

Frequently Asked Questions (FAQ)

Q: Can LD1085V replace LMS1587IT-ADJ in all applications?

A: LD1085V is mechanically and functionally compatible in applications where the input voltage does not exceed 13V and the required output voltage does not exceed 11.7V. The LD1085V supports higher input voltages (up to 30V) and output voltages (up to 28.5V), so it is suitable for the LMS1587IT-ADJ's specified operating range. Both devices share identical output current (3A), adjustable output minimum (1.25V), PSRR (72dB @ 120Hz), and operating temperature range (-40°C ~ 125°C).

Q: Can LT1587CT#PBF replace LMS1587IT-ADJ in all applications?

A: LT1587CT#PBF is compatible only in applications where the input voltage does not exceed 7V and the output voltage requirement does not exceed 5.5V. This substitute has more restrictive voltage specifications than the LMS1587IT-ADJ and a narrower operating temperature range (0°C ~ 125°C versus -40°C ~ 125°C). Verify application voltage requirements before selection.

Q: Are all three devices pin-compatible?

A: All three devices use the TO-220-3 package with through-hole mounting. Pin compatibility for linear regulators in this package class is standard, with input, output, and adjustment pins in equivalent positions. Verify specific pinout documentation for the target application.

Q: What is the significance of the obsolete status of LMS1587IT-ADJ?

A: Obsolete status indicates the part is no longer manufactured by Texas Instruments. The identified substitutes (LD1085V and LT1587CT#PBF) are active products with ongoing manufacturing and supply availability, making them suitable for design continuity and production support.

Q: How do quiescent current differences affect substitute selection?

A: The LMS1587IT-ADJ has a quiescent current of 7 mA, while both substitutes specify 10 mA. In applications with strict power consumption requirements, this 3 mA difference may be significant. Evaluate the impact on total system power budget before final selection.

Q: Does the absence of PSRR specification for LT1587CT#PBF affect its suitability?

A: The LMS1587IT-ADJ and LD1085V both specify 72dB PSRR at 120Hz. The LT1587CT#PBF does not provide this specification in the available data. For applications requiring specific power supply rejection ratio performance, LD1085V is the preferred substitute.