SM12-7 Transient Voltage Suppressor (TVS) Diode - Equivalent & Substitute Parts

Part Overview

The SM12-7 is an automotive-grade transient voltage suppressor diode manufactured by Diodes Incorporated, designed for surface mount applications in SOT-23-3 packaging. This unidirectional TVS diode provides transient protection with a 12V reverse standoff voltage and 19V maximum clamping voltage. The part is active in production with full AEC-Q101 automotive qualification and ROHS3 compliance. Substitute parts may be required due to inventory constraints, supply chain discontinuities, or application-specific performance requirements within compatible electrical and mechanical parameters.

Substiute Parts

SM12-7

Diodes IncorporatedIn Stock: 17336SM12-7 Datasheet

Current PartRFQ

MA3075WALT1G

onsemiIn Stock: 21235MA3075WALT1G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SM12-7 is limited by strict electrical and mechanical compatibility requirements. The primary substitute identified is the MA3075WALT1G from onsemi. However, this substitute operates at a significantly lower voltage rating (6.5V reverse standoff versus 12V) and therefore cannot be considered a direct functional equivalent for applications requiring the SM12-7's 12V protection threshold.

Substitution logic is based on the following criteria:

• Package compatibility: SOT-23-3 surface mount form factor
• Unidirectional channel configuration: 2 channels
• Automotive qualification: AEC-Q101 certification required
• RoHS compliance: ROHS3 Compliant
• Moisture sensitivity: MSL 1 (Unlimited)

The MA3075WALT1G meets packaging, qualification, and compliance requirements but operates outside the voltage specification window of the SM12-7. This part should only be selected if the application circuit can tolerate a 6.5V protection threshold instead of 12V.

Parameter Comparison

Engineering Selection Recommendations

The SM12-7 is the primary component for applications requiring 12V transient voltage suppression with automotive-grade reliability. Both the SM12-7 and MA3075WALT1G hold active product status and carry full AEC-Q101 automotive qualification with ROHS3 compliance, ensuring suitability for regulated automotive environments.

The MA3075WALT1G is not recommended as a substitute for the SM12-7 in applications where the 12V protection threshold is a functional requirement. The 6.5V reverse standoff voltage of the MA3075WALT1G falls outside the electrical specification window of the SM12-7 and would provide inadequate protection for circuits designed around the 12V clamping characteristic.

Selection should be based on the actual voltage protection requirement of the application circuit. If 12V protection is required, the SM12-7 must be used. If a lower voltage threshold (6.5V) is acceptable, the MA3075WALT1G may be considered as an alternative only after circuit validation confirms compatibility with the reduced voltage rating.

Frequently Asked Questions (FAQ)

Q: Can the MA3075WALT1G replace the SM12-7 in my circuit?

A: Only if your application can tolerate a 6.5V protection threshold instead of 12V. The MA3075WALT1G has significantly lower voltage ratings and peak pulse power handling (15W versus 300W). Direct substitution without circuit redesign is not recommended.

Q: Are both parts automotive qualified?

A: Yes. Both the SM12-7 and MA3075WALT1G carry AEC-Q101 automotive qualification and are ROHS3 compliant, making them suitable for regulated automotive applications.

Q: Do both parts use the same package?

A: Yes. Both parts are packaged in SOT-23-3 (TO-236-3, SC-59) surface mount form factor, ensuring mechanical compatibility on the PCB.

Q: What is the operating temperature difference between these parts?

A: The SM12-7 operates from -65°C to 150°C, while the MA3075WALT1G operates from -55°C to 150°C. The SM12-7 provides a 10°C lower temperature rating, which may be critical for applications in extreme cold environments.

Q: Why is the peak pulse power so different between these parts?

A: The SM12-7 is rated for 300W peak pulse power, while the MA3075WALT1G is rated for only 15W. This 20-fold difference reflects fundamentally different design specifications and transient energy handling capabilities. The MA3075WALT1G is not suitable for high-energy transient suppression applications.

Q: Are there any moisture sensitivity concerns?

A: No. Both parts carry MSL 1 (Unlimited) moisture sensitivity level, indicating no moisture-related handling restrictions during storage or assembly.