LM385BYMX-1.2 Equivalent & Substitute Parts

Part Overview

The LM385BYMX-1.2 is a shunt voltage reference IC manufactured by Texas Instruments, designed for precision voltage regulation applications. This component generates a fixed 1.235V output with ±1% tolerance and operates across the 0°C to 70°C temperature range in an 8-SOIC surface mount package. The part is currently listed as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for ongoing production and maintenance applications.

Substiute Parts

LM385BYMX-1.2

Texas InstrumentsIn Stock: 10233LM385BYMX-1.2 Datasheet

Current PartRFQ

LM385BYMX-1.2/NOPB

Texas InstrumentsIn Stock: 3761LM385BYMX-1.2/NOPB Datasheet

DirectRFQ

LM385BD-1.2G

onsemiIn Stock: 5255LM385BD-1.2G Datasheet

MFR RecommendedRFQ

LM385BD-1.2R2G

onsemiIn Stock: 2160LM385BD-1.2R2G Datasheet

MFR RecommendedRFQ

LM385D-1.2G

onsemiIn Stock: 3245LM385D-1.2G Datasheet

MFR RecommendedRFQ

LM385D-1.2R2G

onsemiIn Stock: 21624LM385D-1.2R2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM385BYMX-1.2 is determined by the following critical parameters:

Electrical Compatibility Requirements:

• Fixed output voltage of 1.235V
• Output current capability of 20 mA
• Tolerance specification of ±1% or tighter
• Temperature coefficient within acceptable operational limits
• Noise performance (10Hz to 10kHz) of 60µVrms or lower
• Cathode current specifications compatible with circuit design

Mechanical Compatibility Requirements:

• 8-SOIC package format (0.154", 3.90mm Width)
• Surface mount mounting type
• Moisture Sensitivity Level (MSL) of 1 (Unlimited)

Regulatory & Compliance Considerations:

• RoHS compliance status (preferred for new designs)
• REACH compliance status
• Product status (active preferred over obsolete)

The substitute parts identified below meet these core electrical and mechanical parameters while offering improved product status and compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: LM385BYMX-1.2/NOPB

This Texas Instruments part maintains identical electrical specifications to the original LM385BYMX-1.2, including the tighter 50ppm/°C temperature coefficient and 15 µA cathode current. The primary advantage is active product status and ROHS3 compliance. Packaging is Tape & Reel format, suitable for automated assembly processes. This part provides direct functional equivalence with improved regulatory compliance.

Secondary Recommendations: LM385BD-1.2G and LM385BD-1.2R2G (onsemi)

Both onsemi variants maintain the ±1% tolerance specification and identical output voltage and current ratings. The temperature coefficient increases to 80ppm/°C typical, and cathode current rises to 20 µA. These differences remain within acceptable operational margins for most applications. Both parts carry active status and ROHS3 compliance. LM385BD-1.2R2G offers Tape & Reel packaging for high-volume production; LM385BD-1.2G provides Tube packaging for lower-volume requirements.

Alternative Options: LM385D-1.2G and LM385D-1.2R2G (onsemi)

These onsemi parts feature a wider tolerance specification of -2.4%, +2.01%, which deviates from the original ±1% tolerance. Selection of these parts requires circuit-level tolerance analysis to confirm acceptability. Temperature coefficient and cathode current specifications match the LM385BD variants. Both maintain active status and ROHS3 compliance. Use only when tolerance relaxation is acceptable for the application.

Compliance Advantage:

All recommended substitutes provide ROHS3 compliance and active product status, addressing the obsolescence of the original part while meeting modern regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can LM385D-1.2G and LM385D-1.2R2G be used as direct replacements?

A: These parts are electrically compatible but feature a wider tolerance specification of -2.4%, +2.01% compared to the original ±1%. Direct substitution is possible only if circuit design tolerates this wider specification window. Tolerance analysis at the system level is required before selection.

Q: What is the difference between Tape & Reel and Tube packaging?

A: Tape & Reel packaging is optimized for automated pick-and-place assembly in high-volume production environments. Tube packaging is suitable for lower-volume applications and manual assembly processes. Both formats contain identical die and electrical performance; packaging selection depends on manufacturing process requirements.

Q: Why do onsemi parts show higher cathode current (20 µA vs. 15 µA)?

A: The cathode current specification reflects the minimum current required to maintain regulation. The 5 µA difference is within typical circuit design margins and does not affect functional compatibility. Circuit design should accommodate this specification when selecting onsemi alternatives.

Q: Are all substitute parts RoHS compliant?

A: Yes. All recommended substitutes carry ROHS3 compliance certification. The original LM385BYMX-1.2 is RoHS non-compliant. Substitution provides compliance improvement for new designs and production runs.

Q: What is the significance of the temperature coefficient difference (50ppm/°C vs. 80ppm/°C)?

A: The temperature coefficient defines output voltage drift across the operating temperature range. The original part specifies 50ppm/°C; onsemi alternatives specify 80ppm/°C typical. For the 0°C to 70°C operating range, this represents a maximum drift difference of approximately 2.1mV. Circuit design should accommodate this specification when selecting onsemi parts.

Q: Can I mix different substitute parts in the same production run?

A: All substitute parts maintain identical output voltage (1.235V), output current (20 mA), and package format (8-SOIC). Mixing is possible from a mechanical and basic electrical standpoint. However, tolerance and temperature coefficient variations should be considered in circuit design to ensure consistent performance across the production batch.