LM555CMX Equivalent & Substitute Parts

Part Overview

The LM555CMX is a 555 Type Timer/Oscillator (Single) IC manufactured by Texas Instruments, operating at 100kHz in an 8-SOIC surface mount package. This device is classified as Last Time Buy, indicating discontinued production with limited remaining inventory. Equivalent and substitute parts are necessary to ensure design continuity, maintain supply chain flexibility, and support long-term production requirements for applications utilizing 555 timer functionality.

Substiute Parts

LM555CMX

Texas InstrumentsIn Stock: 44509LM555CMX Datasheet

Current PartRFQ

LM555CMX/NOPB

Texas InstrumentsIn Stock: 77198LM555CMX/NOPB Datasheet

Parametric EquivalentRFQ

NE555DR

UMWIn Stock: 189907NE555DR Datasheet

Parametric EquivalentRFQ

NE555DRG4

Texas InstrumentsIn Stock: 2757NE555DRG4 Datasheet

Parametric EquivalentRFQ

MC1455BDR2G

onsemiIn Stock: 3298MC1455BDR2G Datasheet

MFR RecommendedRFQ

MC1455DR2G

onsemiIn Stock: 25363MC1455DR2G Datasheet

MFR RecommendedRFQ

NCV1455BDR2G

onsemiIn Stock: 55207NCV1455BDR2G Datasheet

MFR RecommendedRFQ

NE555S-13

Diodes IncorporatedIn Stock: 7341NE555S-13 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM555CMX is determined by the following critical parameters:

Functional Compatibility: All substitute parts must be 555 Type Timer/Oscillator (Single) devices with matching pin configuration and functional behavior.

Electrical Parameters: Supply voltage range (4.5V ~ 16V), supply current (10 mA), and frequency capability (100kHz or higher) must be maintained or exceeded.

Package Compatibility: All substitutes must use 8-SOIC surface mount packaging with identical 0.154" (3.90mm) width to ensure PCB layout compatibility.

Environmental Specifications: Operating temperature range and moisture sensitivity level determine suitability for specific application environments.

Compliance Requirements: RoHS3 compliance is mandatory for all substitutes to meet regulatory standards.

Substitute parts are categorized as Parametric Equivalents (matching all critical electrical and mechanical parameters) and Manufacturer Recommended alternatives (offering extended operating ranges or enhanced performance characteristics).

Parameter Comparison

Engineering Selection Recommendations

Primary Equivalent (Recommended): LM555CMX/NOPB is the direct parametric equivalent with identical electrical specifications and Active product status. This part maintains full compatibility with existing designs while ensuring continued availability.

Secondary Equivalent: NE555DR (UMW) provides parametric equivalence with extended frequency range capability (1mHz ~ 100kHz) and Active status. This part is suitable for direct substitution in applications requiring standard 555 timer functionality.

Extended Temperature Range Options: MC1455BDR2G and NCV1455BDR2G (onsemi) offer extended operating temperature ranges (-40°C ~ 85°C and -40°C ~ 125°C respectively) for applications requiring enhanced thermal performance. These parts maintain electrical compatibility while providing broader environmental operating conditions.

Matched Temperature Range: MC1455DR2G (onsemi) matches the original 0°C ~ 70°C operating temperature range with Active product status and full electrical compatibility.

Enhanced Frequency Performance: NE555S-13 (Diodes Incorporated) operates at 500kHz with slightly elevated supply current (13 mA). This part is suitable for applications requiring higher frequency operation within the 555 timer architecture.

Avoid: NE555DRG4 is classified as Obsolete and should not be selected for new designs despite parametric equivalence.

Frequently Asked Questions (FAQ)

Q: Can LM555CMX/NOPB be used as a direct replacement for LM555CMX?

A: Yes. LM555CMX/NOPB is a parametric equivalent with identical electrical and mechanical specifications. The primary difference is product status (Active vs. Last Time Buy), making it the recommended choice for continued supply.

Q: What is the difference between the onsemi MC1455 variants?

A: MC1455BDR2G operates at -40°C ~ 85°C, MC1455DR2G at 0°C ~ 70°C, and NCV1455BDR2G at -40°C ~ 125°C. Selection depends on the required operating temperature range for your application. All maintain identical electrical specifications and 8-SOIC packaging.

Q: Is NE555S-13 compatible with LM555CMX designs?

A: NE555S-13 is functionally compatible but operates at 500kHz (versus 100kHz) with 13 mA supply current (versus 10 mA). Use this part only if your application requires higher frequency operation and can accommodate the increased current draw.

Q: Can I use NE555DRG4 as a substitute?

A: NE555DRG4 is classified as Obsolete and should not be used for new designs or production. Select from Active status alternatives instead.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts maintain ROHS3 compliance, meeting regulatory requirements for hazardous substance restrictions.

Q: Does package compatibility affect substitution?

A: All substitute parts use 8-SOIC (0.154", 3.90mm Width) surface mount packaging, ensuring direct PCB layout compatibility with LM555CMX designs without modification.

Q: Which substitute offers the widest operating temperature range?

A: NCV1455BDR2G provides the widest operating temperature range (-40°C ~ 125°C), suitable for applications requiring extended thermal performance beyond standard industrial specifications.