SMA6F64A Equivalent & Substitute Parts

Part Overview

The SMA6F64A is a unidirectional transient voltage suppressor (TVS) diode manufactured by STMicroelectronics, designed for general-purpose overvoltage protection in surface-mount applications. This component features a 64V reverse standoff voltage with a 134V maximum clamping voltage and 30A peak pulse current capability in an SMAflat (DO-221AC) package.

The SMA6F64A is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for systems utilizing this TVS diode.

Substiute Parts

SMA6F64A

STMicroelectronicsIn Stock: 10632SMA6F64A Datasheet

Current PartRFQ

SMA6J70A-TR

STMicroelectronicsIn Stock: 10110SMA6J70A-TR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the SMA6F64A is determined by alignment of the following critical electrical and mechanical parameters:

Electrical Criteria:

• Reverse standoff voltage within the operating range of the original circuit design
• Breakdown voltage minimum that supports the protection threshold
• Clamping voltage that does not exceed circuit component ratings
• Peak pulse current capability sufficient for transient suppression
• Peak pulse power rating of 600W

Mechanical Criteria:

• Surface-mount package type (SMA or SMAflat variants)
• Operating temperature range of -55°C to 175°C (TJ)
• Unidirectional channel configuration (single channel)

The SMA6J70A-TR qualifies as a substitute based on these parameters. While the reverse standoff voltage is higher (70V versus 64V) and the clamping voltage is lower (120V versus 134V), both values remain within acceptable operating margins for general-purpose TVS applications. Peak pulse current (27A versus 30A) and power rating (600W) are compatible. The package type transitions from SMAflat (DO-221AC) to SMA (DO-214AC), both surface-mount configurations suitable for equivalent board-level integration.

Parameter Comparison

Engineering Selection Recommendations

SMA6J70A-TR is the qualified substitute for SMA6F64A based on the following factors:

Product Status: The SMA6J70A-TR is classified as Active, ensuring ongoing availability and manufacturing support. The SMA6F64A is Obsolete, making the transition to an active part necessary for sustained supply chain operations.

Regulatory Compliance: Both parts maintain identical REACH and ECCN classifications (REACH Unaffected, EAR99), ensuring no change in regulatory handling or export requirements. Both parts carry HTSUS code 8541.10.0080.

Moisture Sensitivity: Both parts are rated MSL 1 (Unlimited), indicating no moisture-related handling restrictions during storage or assembly.

Electrical Performance: The SMA6J70A-TR operates within acceptable margins relative to the SMA6F64A. The 6V increase in reverse standoff voltage (70V versus 64V) provides enhanced protection margin. The 14V reduction in clamping voltage (120V versus 134V) improves transient suppression efficiency. Peak pulse current remains within 90% of the original specification (27A versus 30A), and peak pulse power is maintained at 600W.

Package Compatibility: Both parts are surface-mount configurations. The transition from SMAflat (DO-221AC) to SMA (DO-214AC) requires verification of board-level footprint compatibility, as these packages have different lead geometries and land patterns.

Frequently Asked Questions (FAQ)

Q: Can the SMA6J70A-TR directly replace the SMA6F64A without circuit modification?

A: Electrical substitution is valid based on voltage and current parameters. However, the package transition from SMAflat (DO-221AC) to SMA (DO-214AC) requires PCB footprint verification. These packages have different lead configurations and land patterns. Board redesign may be necessary.

Q: What is the significance of the 6V difference in reverse standoff voltage?

A: The SMA6J70A-TR operates at 70V reverse standoff versus 64V for the SMA6F64A. This 6V increase means the substitute part triggers protection at a higher voltage threshold. For circuits designed around the 64V threshold, this difference must be evaluated against actual circuit operating conditions and transient profiles.

Q: Why is the clamping voltage lower on the substitute part?

A: The SMA6J70A-TR clamps at 120V maximum versus 134V for the SMA6F64A. Lower clamping voltage provides faster transient suppression and reduced voltage stress on protected components. This is generally beneficial for circuit protection, provided downstream components are rated for 120V operation.

Q: Are there any compliance or regulatory differences between these parts?

A: No. Both parts share identical REACH status (REACH Unaffected), ECCN classification (EAR99), and HTSUS codes (8541.10.0080). Moisture sensitivity levels are identical (MSL 1, Unlimited). No regulatory or compliance changes result from substitution.

Q: What is the impact of the 3A reduction in peak pulse current?

A: The SMA6J70A-TR is rated for 27A peak pulse current versus 30A for the SMA6F64A. This represents a 10% reduction. For applications with transient currents consistently below 27A, this difference is not significant. Applications with peak transient currents exceeding 27A require detailed analysis to confirm adequate protection margin.

Q: Is the SMA6J70A-TR suitable for new designs?

A: Yes. The SMA6J70A-TR is classified as Active, making it suitable for new product development. The SMA6F64A is Obsolete and should not be specified for new designs.

Q: What is the difference between SMAflat and SMA packages?

A: SMAflat (DO-221AC) and SMA (DO-214AC) are both surface-mount TVS diode packages but have different physical dimensions and lead configurations. SMAflat features flat leads, while SMA features standard bent leads. PCB footprints are not interchangeable without redesign.