SMF20A-M3-18 Equivalent & Substitute Parts

Part Overview

The SMF20A-M3-18 is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Vishay General Semiconductor - Diodes Division. This component is part of the eSMP® series and is designed for general-purpose transient voltage suppression applications. The device features a 20V reverse standoff voltage with a 32.4V maximum clamping voltage and 6.2A peak pulse current capability. The SMF20A-M3-18 is currently in active production status with 946 pieces available in inventory. Equivalent and substitute parts are identified when they maintain identical or functionally compatible electrical parameters while meeting the same application requirements and compliance standards.

Substiute Parts

SMF20A-M3-18

Vishay General Semiconductor - Diodes DivisionIn Stock: 1036SMF20A-M3-18 Datasheet

Current PartRFQ

SMF20A-HM3-08

Vishay General Semiconductor - Diodes DivisionIn Stock: 30904SMF20A-HM3-08 Datasheet

DirectRFQ

SZSMF20AT1G

Littelfuse Inc.In Stock: 2939SZSMF20AT1G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SMF20A-M3-18 are qualified based on the following critical electrical and mechanical parameters:

• Voltage - Reverse Standoff (Typ): 20V
• Voltage - Breakdown (Min): 22.2V
• Voltage - Clamping (Max) @ Ipp: 32.4V
• Current - Peak Pulse (10/1000µs): 6.2A
• Power - Peak Pulse: 200W
• Type: Zener, Unidirectional
• RoHS Status: ROHS3 Compliant
• Mounting Type: Surface Mount

Two substitute parts meet these criteria. The SMF20A-HM3-08 is a direct equivalent from the same manufacturer (Vishay) with identical electrical specifications and the same DO-219AB package. The SZSMF20AT1G is a manufacturer-recommended substitute from Littelfuse Inc. with matching electrical parameters but uses the SOD-123F package instead of DO-219AB. Both substitutes maintain the same voltage ratings, peak pulse current, and power dissipation characteristics required for equivalent circuit protection performance.

Parameter Comparison

Engineering Selection Recommendations

All three parts maintain active production status and ROHS3 compliance. The SMF20A-HM3-08 provides a direct package-compatible substitute with identical electrical specifications and the same DO-219AB footprint. This part is qualified to automotive standards (AEC-Q101) and offers the highest inventory availability at 30,806 pieces.

The SZSMF20AT1G from Littelfuse is a manufacturer-recommended alternative with equivalent electrical performance and automotive qualification (AEC-Q101). This part uses the SOD-123F package, which requires PCB layout modification compared to the original DO-219AB package. The operating temperature range is reduced to -55 to 150°C (TJ) compared to the SMF20A-M3-18 specification of -65 to 175°C (TJ).

Selection between these substitutes depends on package compatibility requirements and thermal operating range constraints specific to the application circuit.

Frequently Asked Questions (FAQ)

Q: Can SMF20A-HM3-08 be used as a direct replacement for SMF20A-M3-18?

A: Yes. Both parts share identical electrical specifications (20V standoff, 22.2V breakdown, 32.4V clamping, 6.2A peak pulse current, 200W peak power) and use the same DO-219AB package. PCB layout and component placement remain unchanged.

Q: What is the primary difference between SMF20A-HM3-08 and SZSMF20AT1G?

A: The SMF20A-HM3-08 maintains the DO-219AB package footprint identical to the original part. The SZSMF20AT1G uses the SOD-123F package, requiring PCB redesign. Additionally, SZSMF20AT1G has a reduced operating temperature range (-55 to 150°C vs. -65 to 175°C).

Q: Are all three parts automotive-qualified?

A: The SMF20A-HM3-08 and SZSMF20AT1G both carry AEC-Q101 automotive qualification. The SMF20A-M3-18 does not list automotive qualification in the provided specifications.

Q: Do these parts have identical capacitance characteristics?

A: The SMF20A-M3-18 and SMF20A-HM3-08 both specify 283pF capacitance at 1MHz. The SZSMF20AT1G does not provide capacitance data in the available specifications.

Q: Which substitute has the best inventory availability?

A: The SMF20A-HM3-08 has 30,806 pieces in stock, compared to 2,864 pieces for SZSMF20AT1G and 946 pieces for the original SMF20A-M3-18.