RC1585M Equivalent & Substitute Parts

Part Overview

The RC1585M is an obsolete Intel Pentium® II GTL+ Pro Voltage Regulator IC manufactured by onsemi. This single-output converter operates with input voltage range of 4.6V to 7V and delivers adjustable output voltage from 1.5V to 3.6V. The part is packaged in TO-263-3 (D2PAK) surface mount configuration and is no longer in active production. Due to its obsolete status, identifying functionally equivalent substitute parts is essential for system redesign, legacy product support, and component procurement.

Substiute Parts

RC1585M

onsemiIn Stock: 3074RC1585M Datasheet

Current PartRFQ

LMS1585ACSX-ADJ/NOPB

National SemiconductorIn Stock: 2445LMS1585ACSX-ADJ/NOPB Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the RC1585M is determined by the following critical parameters:

• Input Voltage Compatibility: The substitute must accept input voltage within or exceeding the 4.6V ~ 7V range
• Output Voltage Range: The substitute must provide adjustable output voltage that encompasses or exceeds the 1.5V ~ 3.6V range
• Single Output Configuration: Only single-output regulators qualify as direct substitutes
• Package Compatibility: Surface mount TO-263 (D2PAK) packaging ensures mechanical and thermal compatibility
• Operating Temperature Range: The substitute must support the 0°C ~ 125°C operating window
• Regulatory Compliance: REACH and ECCN classifications must align with the original part

The LMS1585ACSX-ADJ/NOPB from National Semiconductor meets these substitution criteria through its adjustable output configuration, compatible packaging, and overlapping electrical specifications.

Parameter Comparison

Engineering Selection Recommendations

The LMS1585ACSX-ADJ/NOPB qualifies as a functional substitute for the obsolete RC1585M based on the following engineering criteria:

Electrical Compatibility: The LMS1585ACSX-ADJ/NOPB provides adjustable output voltage from 1.25V to 11.6V, which fully encompasses the RC1585M's 1.5V to 3.6V output range. The substitute accepts input voltage up to 13V, exceeding the RC1585M's 7V maximum, providing additional design margin.

Package and Thermal Compatibility: Both parts use TO-263 (D2PAK) surface mount packaging with identical lead configuration (3 Leads + Tab), ensuring direct PCB layout compatibility without redesign.

Operating Environment: Both parts operate across the 0°C to 125°C temperature range, maintaining functional equivalence in the same thermal envelope.

Regulatory Alignment: Both parts carry EAR99 ECCN classification, ensuring consistent export compliance. The substitute's active product status provides long-term availability and supply chain stability compared to the obsolete RC1585M.

Availability: The LMS1585ACSX-ADJ/NOPB is currently in active production with 2353 pieces in stock, providing immediate procurement capability versus the limited remaining inventory of the obsolete RC1585M.

Frequently Asked Questions (FAQ)

Q: Can the LMS1585ACSX-ADJ/NOPB directly replace the RC1585M without PCB modifications?

A: Yes. Both parts use identical TO-263 (D2PAK) packaging with the same pinout configuration (3 Leads + Tab). No PCB layout changes are required for mechanical and electrical connection.

Q: What is the key difference in output voltage capability between these parts?

A: The RC1585M provides output voltage from 1.5V to 3.6V, while the LMS1585ACSX-ADJ/NOPB provides 1.25V to 11.6V. The substitute covers the original range and extends capability for broader application flexibility.

Q: Are there input voltage considerations when substituting?

A: The RC1585M accepts 4.6V to 7V input, while the LMS1585ACSX-ADJ/NOPB accepts up to 13V input. If your circuit supplies voltage above 7V, the substitute provides additional headroom. If your circuit supplies below 4.6V, verify the substitute's minimum input requirement aligns with your power source.

Q: Do both parts have the same operating temperature range?

A: Yes. Both the RC1585M and LMS1585ACSX-ADJ/NOPB operate from 0°C to 125°C, ensuring equivalent thermal performance in the same application environment.

Q: What is the output current capability of the LMS1585ACSX-ADJ/NOPB?

A: The LMS1585ACSX-ADJ/NOPB provides 5A maximum output current. Verify that your application's current requirements do not exceed this specification.

Q: Are there any compliance or certification differences?

A: Both parts carry EAR99 ECCN classification and are REACH compliant. No additional compliance documentation is required when substituting between these parts.

Q: Why is the RC1585M obsolete?

A: The RC1585M was designed specifically for Intel Pentium® II GTL+ Pro processors, which are no longer in production. As the target application became obsolete, component production ceased. The LMS1585ACSX-ADJ/NOPB provides equivalent voltage regulation functionality for modern applications.