Vishay General Semiconductor - Diodes Division SM6T36A-M3/5B

Overview

SM6T36A-M3/5B from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMB (DO-214AA) package, with 34.2 V minimum breakdown voltage (V_BR), 30.8 V standoff voltage (V_WM), 49.9 V clamping voltage (V_C) at 12.0 A peak pulse current, and 600 W peak pulse power rating per 10/1000 μs waveform - deployed for overvoltage protection of MOSFETs, ICs, and sensor signal lines in automotive and industrial control systems.

For engineers reviewing the SM6T36A-M3/5B datasheet, SM6T36A-M3/5B pinout, SM6T36A-M3/5B application, or SM6T36A-M3/5B equivalent, key selection considerations include verified clamping performance under 10/1000 μs transients, halogen-free RoHS-compliant construction (M3 suffix), SMB package thermal resistance (R_θJA = 100 °C/W), and AEC-Q101 qualification availability via HM3 variant.

Technical Context

The SM6T36A-M3/5B operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its 34.2–37.8 V breakdown range at 1 mA test current. Its low-inductance SMB package enables fast response to ESD and lightning-induced transients, with clamping action limiting downstream voltage to ≤49.9 V at 12.0 A (10/1000 μs).

Designed for board-level surge immunity, it sustains 100 A non-repetitive forward surge (10 ms half-sine) and operates across –65 °C to +150 °C junction temperature. The cathode band denotes polarity; no marking on bidirectional variants. Thermal derating applies above 25 °C ambient per Fig. 2.

Key Specifications

Pinout & Package

SMB (DO-214AA) package: molded plastic case meeting UL 94 V-0 flammability rating; matte tin-plated leads solderable per J-STD-002 and JESD 22-B102; cathode indicated by band on unidirectional devices like SM6T36A-M3/5B.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with SMAJ36A-E3/5B and SMCJ36A-M3/5B, the SM6T36A-M3/5B delivers optimal balance of 600 W surge capacity, SMB footprint, and halogen-free compliance - making it ideal for cost-sensitive automotive modules and industrial sensors where moderate surge immunity and RoHS adherence are jointly required.

Availability

SM6T36A-M3/5B is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, and consumer power adapter designs requiring stable component supply, halogen-free compliance, and proven transient immunity per IEC 61000-4-2/4-5.

Supply support for SM6T36A-M3/5B includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.

The SM6T Series was engineered for surface-mount transient suppression in space-constrained, high-volume applications - delivering consistent clamping performance, AEC-Q101 qualification pathways, and compatibility with automated SMT assembly lines.

FAQ

What is the clamping voltage of SM6T36A-M3/5B at its rated peak pulse current?

The SM6T36A-M3/5B has a maximum clamping voltage (V_C) of 49.9 V at 12.0 A peak pulse current under the 10/1000 μs waveform condition. This value is measured per Figure 1 in the official Vishay datasheet (Doc. #88385, Rev. 09-Jan-2024) and defines the upper voltage limit imposed on protected circuits during surge events. It reflects actual device behavior under standardized test conditions, not a theoretical or derated figure.

Is SM6T36A-M3/5B suitable for automotive applications requiring AEC-Q101 qualification?

The SM6T36A-M3/5B itself is not AEC-Q101 qualified; it carries the M3 suffix indicating halogen-free RoHS compliance for commercial use. However, Vishay offers the functionally identical SM6T36AHM3_B/I variant - which shares the same electrical specs and SMB package - explicitly qualified to AEC-Q101. Engineers requiring automotive-grade validation must specify that variant, not SM6T36A-M3/5B.

What is the standoff voltage (V_WM) of SM6T36A-M3/5B and how does it relate to system operating voltage?

The SM6T36A-M3/5B has a standoff voltage (V_WM) of 30.8 V, meaning it remains non-conductive with leakage <1.0 μA up to this reverse voltage. For reliable operation, system DC operating voltage must stay below V_WM - e.g., it is appropriate for 24 V nominal systems (max transient-tolerant rail ~28.8 V) but not for 36 V or 48 V buses without derating or additional series impedance.

Does SM6T36A-M3/5B have bidirectional capability?

No, SM6T36A-M3/5B is strictly unidirectional, as indicated by the "A" suffix and cathode band marking. Bidirectional functionality requires the "CA" suffix (e.g., SM6T36CA). Using SM6T36A-M3/5B on AC-coupled or bipolar signal lines would result in forward conduction during negative half-cycles, potentially damaging the device or circuit.

What is the thermal resistance of SM6T36A-M3/5B and how does it affect PCB layout?

The SM6T36A-M3/5B has a typical junction-to-ambient thermal resistance (R_θJA) of 100 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. To maintain safe junction temperatures under repeated surges, PCB layout must provide at least this pad area - reducing copper area increases R_θJA, risking thermal failure during high-duty-cycle transients.