SM8S26A-TP Equivalent & Substitute Parts

Part Overview

The SM8S26A-TP is a unidirectional Zener transient voltage suppressor (TVS) diode designed for surface mount applications in automotive-grade circuits. It provides transient overvoltage protection with a 26V reverse standoff voltage and 42.1V maximum clamping voltage. The device is rated for 157A peak pulse current and 6.6kW peak pulse power dissipation across an operating temperature range of -55°C to 175°C.

This part carries a "Not For New Designs" status, making identification of equivalent substitute components essential for ongoing production and design continuity. Suitable alternatives must maintain identical electrical performance parameters while accommodating different packaging and availability constraints.

Substiute Parts

SM8S26A-TP

Micro Commercial CoIn Stock: 10121SM8S26A-TP Datasheet

Current PartRFQ

SLD8S26A

LittelfuseIn Stock: 359387SLD8S26A Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SM8S26A-TP is determined by strict equivalence across the following critical parameters:

Voltage specifications must match exactly: 26V reverse standoff, 28.9V minimum breakdown, and 42.1V maximum clamping voltage. These parameters define the protection threshold and response characteristics of the TVS diode.

Current and power ratings must meet or exceed the original specification: 157A peak pulse current (10/1000µs waveform) and 6.6kW peak pulse power dissipation. Substitute parts with lower ratings are not acceptable.

Operating temperature range must span the full -55°C to 175°C specification to ensure performance across automotive thermal extremes.

Automotive-grade classification and AEC-Q101 qualification are mandatory for applications requiring automotive compliance.

Unidirectional topology (single channel) must be preserved for circuit compatibility.

RoHS3 compliance and MSL 1 rating must be maintained for manufacturing and environmental requirements.

Package type may differ (DO-218AB versus alternative surface mount packages) provided the footprint is compatible with the circuit board design and assembly process.

Parameter Comparison

Engineering Selection Recommendations

The SLD8S26A from Littelfuse qualifies as a direct electrical substitute for the SM8S26A-TP. All critical voltage and current parameters are equivalent or exceed the original specification. The substitute device maintains automotive-grade classification and AEC-Q101 qualification, ensuring compliance with automotive reliability and qualification standards.

The primary consideration for substitution is package compatibility. The SM8S26A-TP uses a DO-218AB package, while the SLD8S26A employs an SMTO-263 package. Circuit board layout and assembly equipment must accommodate the different footprint and lead configuration. Mechanical verification against PCB design files is required before implementation.

The SLD8S26A carries an "Active" product status, providing long-term availability and supply chain stability compared to the "Not For New Designs" status of the original part. This status transition supports production continuity and future design iterations.

Both devices maintain identical RoHS3 compliance and MSL 1 ratings, eliminating environmental and manufacturing process concerns during substitution.

Frequently Asked Questions (FAQ)

Q: Can the SLD8S26A replace the SM8S26A-TP in existing designs without circuit modification?

A: Electrical substitution is valid. The SLD8S26A meets or exceeds all voltage, current, and power specifications. However, package differences (DO-218AB versus SMTO-263) require PCB layout verification. If the circuit board footprint is designed specifically for DO-218AB, physical compatibility must be confirmed or the board redesigned for SMTO-263 before implementation.

Q: What is the significance of the higher peak pulse current (167A) and power rating (7kW) in the SLD8S26A?

A: The substitute part's higher ratings provide additional margin above the original 157A and 6.6kW specifications. This does not affect circuit operation; the device will clamp at the same 42.1V voltage threshold. The increased ratings enhance reliability and thermal headroom under transient overvoltage events.

Q: Are both parts suitable for automotive applications?

A: Yes. Both the SM8S26A-TP and SLD8S26A carry automotive-grade classification and AEC-Q101 qualification, meeting automotive reliability and qualification requirements.

Q: What packaging formats are available for each part?

A: The SM8S26A-TP is supplied in Tape & Reel (TR) format. The SLD8S26A is available in Cut Tape (CT) and Digi-Reel® formats. Packaging selection depends on assembly process requirements and volume considerations.

Q: Why is the SM8S26A-TP marked "Not For New Designs"?

A: This status indicates the manufacturer is discontinuing the part for new design applications. Existing production may continue, but new designs should transition to active alternatives such as the SLD8S26A to ensure long-term supply availability.

Q: Are there any compliance or certification differences between the two parts?

A: No. Both parts maintain ROHS3 compliance, MSL 1 rating, and AEC-Q101 automotive qualification. Substitution does not introduce compliance concerns.