Vishay General Semiconductor - Diodes Division SM6T27CAHM3_B/H

Overview

SM6T27CAHM3_B/H from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, rated for 600 W peak pulse power (10/1000 μs), 27 V breakdown voltage (V_BR = 25.7–28.4 V at 1 mA), 37.5 V maximum clamping voltage at I_PPM, and 150 °C max junction temperature. It protects signal lines and power rails in automotive sensor units and industrial control interfaces against ESD and inductive switching transients.

For engineers reviewing the SM6T27CAHM3_B/H datasheet, SM6T27CAHM3_B/H pinout, SM6T27CAHM3_B/H application, or SM6T27CAHM3_B/H equivalent, key selection criteria include bidirectional clamping symmetry, AEC-Q101 qualification status, 37.5 V clamping performance at 16.0 A peak pulse current, halogen-free RoHS compliance, and SMB package thermal resistance (R_θJA = 100 °C/W).

Technical Context

This bidirectional TVS operates with symmetrical reverse standoff (V_WM = 23.1 V) and breakdown characteristics in both directions, enabling protection of AC-coupled or differential signal paths without polarity concerns. Its glass-passivated junction ensures stable leakage (<1.0 μA at V_WM) and low inductance for fast response to sub-nanosecond transients.

The device is qualified to AEC-Q101 and manufactured with halogen-free molding compound (HM3 suffix), meeting JESD201 Class 2 whisker resistance and MSL Level 1 reflow compatibility (260 °C peak). Thermal design relies on 0.2" × 0.2" copper pads per terminal to sustain 600 W pulse dissipation.

Key Specifications

Pinout & Package

SM6T27CAHM3_B/H uses an SMB (DO-214AA) package with two terminals: anode and cathode. As a bidirectional device, it has no polarity marking; both terminals are functionally symmetric and interchangeable in circuit layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ24CA and SMCJ24CA, SM6T27CAHM3_B/H delivers optimal balance of 600 W surge capacity, SMB footprint, AEC-Q101 qualification, and halogen-free compliance-making it preferred for space-constrained automotive and industrial signal-line protection where 16 A peak current is the design target.

Availability

SM6T27CAHM3_B/H is available at Aetrix Electronics and suitable for automotive sensor modules, industrial CAN bus nodes, and telecom line card designs requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for SM6T27CAHM3_B/H 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 is designed specifically for robust, surface-mount transient suppression in automotive, industrial, and communications systems-prioritizing AEC-Q101 qualification, low-clamp performance, and automated assembly compatibility.

FAQ

What is the clamping voltage of SM6T27CAHM3_B/H at its rated peak pulse current?

The SM6T27CAHM3_B/H has a maximum clamping voltage (V_C) of 37.5 V when subjected to its rated peak pulse current of 16.0 A using the standard 10/1000 μs waveform. This value is measured across the device terminals during transient conduction and represents the upper voltage limit imposed on protected circuitry during surge events. The clamping performance is symmetrical due to the device's bidirectional structure, ensuring consistent protection regardless of surge polarity. SM6T27CAHM3_B/H maintains this specification across its full operating temperature range.

Is SM6T27CAHM3_B/H qualified for automotive applications?

Yes, SM6T27CAHM3_B/H is AEC-Q101 qualified, as indicated by the "HM3" suffix in its ordering code. This qualification confirms that the device has passed stress tests covering temperature cycling, humidity, mechanical shock, and accelerated life testing required for automotive electronic components. It is suitable for use in engine control units, body electronics, ADAS sensors, and infotainment systems where reliability under harsh environmental conditions is mandatory. SM6T27CAHM3_B/H meets these requirements while retaining halogen-free and RoHS-compliant construction.

What does the "CA" suffix signify in SM6T27CAHM3_B/H?

The "CA" suffix in SM6T27CAHM3_B/H explicitly denotes a bidirectional configuration, meaning the device provides symmetrical transient voltage suppression in both forward and reverse directions. Unlike unidirectional variants (e.g., SM6T27AHM3_B/H), the CA version has no cathode marking and functions identically regardless of terminal orientation. This makes SM6T27CAHM3_B/H ideal for protecting AC-coupled signals, differential buses like CAN or RS-485, and floating power domains where polarity cannot be guaranteed. The breakdown and clamping parameters apply equally in either direction.

What is the maximum steady-state power dissipation for SM6T27CAHM3_B/H?

The maximum steady-state power dissipation (P_D) for SM6T27CAHM3_B/H is 5.0 W at an ambient temperature of 50 °C with infinite heatsink conditions. This rating assumes proper PCB thermal design-specifically, mounting on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. At higher ambient temperatures, derating is required per Figure 2 in the Vishay datasheet (Document Number: 88385). SM6T27CAHM3_B/H is not intended for continuous power dissipation but rather for transient energy absorption; sustained DC power above 5.0 W will exceed thermal limits and cause failure.

How does the SMB (DO-214AA) package of SM6T27CAHM3_B/H compare to SMC (DO-214AB) in thermal performance?

The SMB (DO-214AA) package used by SM6T27CAHM3_B/H has a typical junction-to-ambient thermal resistance (R_θJA) of 100 °C/W, whereas the larger SMC (DO-214AB) package offers ~60–70 °C/W under identical pad conditions. This means SM6T27CAHM3_B/H requires more careful thermal layout-such as increased copper area or internal layers-to manage heat during repeated surge events. However, its smaller footprint supports high-density layouts in space-constrained applications like automotive ECUs and compact industrial modules. SM6T27CAHM3_B/H achieves its 600 W pulse rating through optimized silicon and short transient duration, not steady-state conduction.