MSG140 Schottky Diode 40V 1A DO-204AL Equivalent & Substitute Parts

Part Overview

The MSG140 is a Schottky rectifier diode rated for 40V DC reverse voltage and 1A average rectified current in a DO-204AL (DO-41) through-hole axial package. This component is classified as obsolete, necessitating identification of active equivalent parts for new designs and ongoing production requirements. Schottky diodes in this voltage and current class are commonly used in power supply circuits, reverse polarity protection, and high-frequency switching applications where fast recovery characteristics are required.

Substiute Parts

MSG140

Microchip TechnologyIn Stock: 1173MSG140 Datasheet

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MSG104

Microsemi CorporationIn Stock: 1012MSG104 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MSG140 is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• Voltage - DC Reverse (Vr) (Max): 40V
• Current - Average Rectified (Io): 1A
• Technology: Schottky
• Mounting Type: Through Hole
• Package / Case: DO-204AL (DO-41) Axial

Allowable Variation Parameters:

• Voltage - Forward (Vf) (Max) @ If: Substitute parts may exhibit higher forward voltage drop within the Schottky diode characteristic range
• Operating Temperature - Junction: Substitute parts may support extended upper temperature limits
• Product Status: Active substitutes are preferred over obsolete parts

The MSG104 manufactured by Microsemi Corporation meets all mandatory matching criteria and qualifies as a direct substitute for the MSG140.

Parameter Comparison

Engineering Selection Recommendations

MSG104 as Primary Substitute:

The MSG104 is the qualified substitute for MSG140 applications. Both devices share identical voltage and current ratings, package configuration, and recovery speed characteristics. The MSG104 is currently in active production status, ensuring long-term availability and supply chain continuity.

Electrical Compatibility:

The MSG104 exhibits a higher forward voltage drop (690 mV vs. 580 mV at 1A). This 110 mV difference must be evaluated within the context of the application circuit. In power supply and rectification circuits, this variance affects efficiency and heat dissipation but does not compromise functional compatibility for standard 40V/1A Schottky diode applications.

Thermal Considerations:

The MSG104 supports an extended operating temperature range (-65°C to 175°C) compared to the MSG140 (-65°C to 150°C). This provides additional thermal margin in applications subject to elevated ambient or self-heating conditions.

Compliance and Certification:

Both the MSG140 and MSG104 carry identical RoHS non-compliance status, REACH unaffected classification, and EAR99 ECCN designation. No compliance advantage exists between the two parts. Moisture sensitivity level (MSL 1) is equivalent, indicating unlimited shelf life under standard storage conditions.

Frequently Asked Questions (FAQ)

Q: Can MSG104 directly replace MSG140 in existing designs?

A: Yes. The MSG104 meets all mandatory electrical and mechanical specifications for MSG140 substitution. The devices are pin-compatible in DO-204AL axial through-hole applications and share identical voltage, current, and speed ratings.

Q: What is the significance of the 110 mV forward voltage difference?

A: The MSG104 forward voltage (690 mV @ 1A) is higher than the MSG140 (580 mV @ 1A). In rectification circuits, this increases power dissipation proportionally to load current. Circuit designers must verify that thermal management and voltage regulation remain within specification with the higher forward drop.

Q: Are there any temperature-related limitations when substituting MSG104 for MSG140?

A: No. The MSG104 supports a higher maximum junction temperature (175°C vs. 150°C), providing additional thermal headroom. Applications operating within the MSG140 temperature range are fully compatible with MSG104 thermal specifications.

Q: Does the MSG104 have the same package footprint as MSG140?

A: Yes. Both devices use the DO-204AL (DO-41) axial through-hole package. Physical dimensions, lead spacing, and mounting characteristics are identical, enabling direct board-level substitution without layout modifications.

Q: What is the product status difference, and why does it matter?

A: MSG140 is obsolete, indicating discontinued production and limited inventory availability. MSG104 is active, ensuring ongoing manufacturing and reliable supply chain access for current and future production runs.

Q: Are there compliance or certification differences between these parts?

A: No. Both parts share identical RoHS status (non-compliant), REACH classification (unaffected), and ECCN designation (EAR99). No regulatory advantage exists between the two devices.

Q: Can MSG104 be used in high-frequency switching applications?

A: Yes. The MSG104 meets the fast recovery specification (≤ 500ns for currents > 200mA), qualifying it for high-frequency switching, power factor correction, and other applications requiring rapid diode turn-off characteristics.