RC1587M Equivalent & Substitute Parts

Part Overview

The RC1587M is an obsolete Intel Pentium II GTL+ Pro Voltage Regulator IC manufactured by onsemi, designed as a single-output converter for legacy processor power management applications. The part operates with input voltage range of 4.5V to 7V and adjustable output voltage from 1.5V to 3.6V in a TO-263-3 surface mount package. Due to its obsolete product status, equivalent substitute parts from active manufacturers are necessary for system redesigns, repairs, and new production requirements.

Substiute Parts

RC1587M

onsemiIn Stock: 1764RC1587M Datasheet

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LMS1587CS-ADJ/NOPB

Texas InstrumentsIn Stock: 1379LMS1587CS-ADJ/NOPB Datasheet

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LMS1587CSX-ADJ/NOPB

Texas InstrumentsIn Stock: 1633LMS1587CSX-ADJ/NOPB Datasheet

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LMS1587IS-ADJ/NOPB

National SemiconductorIn Stock: 1624LMS1587IS-ADJ/NOPB Datasheet

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LMS1587ISX-ADJ/NOPB

National SemiconductorIn Stock: 1675LMS1587ISX-ADJ/NOPB Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the RC1587M are qualified based on the following critical parameters that determine functional and mechanical compatibility:

Electrical Compatibility Criteria:

• Output Configuration: Positive adjustable output
• Number of Outputs: Single output (1)
• Package / Case: TO-263-3 (D2PAK, 3 Leads + Tab) — identical pinout and form factor
• Voltage - Input (Max): Must accommodate or exceed 7V input
• Voltage - Output Range: Must support adjustable output capability with minimum 1.25V and maximum output voltage ≥ 3.6V
• Operating Temperature: Must support 0°C ~ 125°C minimum range
• Current - Output: 3A rated output current

Mechanical Compatibility Criteria:

• Surface mount TO-263 package with identical lead configuration
• Identical thermal and mechanical footprint

All four substitute parts meet these criteria and are manufactured by Texas Instruments and National Semiconductor, both active suppliers with current product status.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Texas Instruments LMS1587 Series): LMS1587CS-ADJ/NOPB and LMS1587CSX-ADJ/NOPB are functionally equivalent to RC1587M with active product status and ROHS3 compliance. Both parts are identical in electrical performance and package configuration. Selection between these two variants depends on packaging requirements: LMS1587CS-ADJ/NOPB is supplied in Tube packaging, while LMS1587CSX-ADJ/NOPB is supplied in Cut Tape (CT) & Digi-Reel® format. Both operate within the 0°C to 125°C temperature range matching the original specification.

Extended Temperature Substitutes (National Semiconductor LMS1587 Series): LMS1587IS-ADJ/NOPB and LMS1587ISX-ADJ/NOPB provide identical electrical functionality with extended operating temperature range of -40°C to 125°C, offering superior performance in temperature-critical applications. These parts are suitable for environments requiring lower temperature operation beyond the RC1587M specification. Selection between variants depends on packaging: LMS1587IS-ADJ/NOPB is supplied without specified packaging, while LMS1587ISX-ADJ/NOPB is supplied in Bulk format.

All substitute parts maintain identical TO-263 package geometry, pinout compatibility, and electrical output characteristics within the specified voltage and current ranges. The higher maximum input voltage (13V vs. 7V) and extended output voltage range (1.25V to 11.7V) of substitute parts provide design flexibility without compromising compatibility with legacy RC1587M circuit designs.

Frequently Asked Questions (FAQ)

Q: Can LMS1587 parts directly replace RC1587M without PCB modifications? A: Yes. All substitute parts use identical TO-263 (D2PAK-3) package geometry with matching pinout. Direct PCB footprint compatibility is confirmed. No layout changes are required.

Q: What is the difference between LMS1587CS-ADJ/NOPB and LMS1587CSX-ADJ/NOPB? A: Both parts are electrically identical. The difference is packaging format: CS-ADJ/NOPB is supplied in Tube, while CSX-ADJ/NOPB is supplied in Cut Tape & Digi-Reel. Select based on assembly process requirements.

Q: Why do National Semiconductor LMS1587IS variants have -40°C to 125°C temperature range while Texas Instruments variants are 0°C to 125°C? A: Both temperature ranges exceed the RC1587M minimum specification of 0°C to 125°C. National Semiconductor variants provide extended lower temperature capability for applications requiring operation below 0°C. For standard 0°C to 125°C applications, either variant is acceptable.

Q: Are all substitute parts RoHS compliant? A: Texas Instruments LMS1587 variants are ROHS3 compliant. National Semiconductor variants do not specify RoHS status in provided data. Verify RoHS compliance requirements with your supply chain if mandated by application standards.

Q: What is the maximum input voltage for substitute parts compared to RC1587M? A: RC1587M maximum input is 7V. All LMS1587 substitutes accept 13V maximum input, providing design margin and compatibility with higher input voltage sources without circuit modification.

Q: Can I use LMS1587 parts in applications requiring the full 1.5V to 3.6V output range of RC1587M? A: Yes. LMS1587 parts support 1.25V to 11.7V adjustable output range, which fully encompasses the RC1587M 1.5V to 3.6V specification. Output voltage is set by external resistor network and is fully adjustable within the LMS1587 range.