Vishay General Semiconductor - Diodes Division SMCJ170CAHM3_A/H

Overview

SMCJ170CAHM3_A/H from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMC (DO-214AB) package, designed for high-energy surge protection with 1500 W peak pulse power rating, 170 V standoff voltage (VWM), and clamping voltage of 275 V at 5.5 A peak pulse current. It protects sensitive signal lines and power rails in automotive ECUs, industrial motor drives, and telecom interface circuits against lightning-induced transients and inductive switching spikes.

For engineers reviewing the SMCJ170CAHM3_A/H datasheet, SMCJ170CAHM3_A/H pinout, SMCJ170CAHM3_A/H application, or SMCJ170CAHM3_A/H equivalent, key selection criteria include bidirectional clamping symmetry, AEC-Q101 qualification status, 1500 W 10/1000 µs surge capability, thermal resistance (R_θJA = 75 °C/W), and halogen-free RoHS compliance per HM3 suffix.

Technical Context

This device operates as a voltage-clamped crowbar during overvoltage events, leveraging an avalanche breakdown mechanism with low incremental surge resistance and fast response time (< 1 ns). Its bidirectional structure enables symmetric clamping in AC-coupled or floating signal paths without polarity concerns.

Designed for surface-mount automated assembly, it features glass-passivated junctions, matte tin-plated leads compliant with J-STD-002, and meets MSL Level 1 per J-STD-020 with 260 °C reflow peak. The SMC (DO-214AB) package supports 0.31" × 0.31" copper pad layout for optimal thermal dissipation under repetitive surge conditions.

Key Specifications

Pinout & Package

Package: SMC (DO-214AB), surface-mount, bidirectional configuration with no polarity marking; case dimensions 7.11 mm × 6.22 mm × 2.62 mm (L × W × H); terminals are matte tin-plated leads suitable for lead-free reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMCJ170CAHM3_A/H, SMAJ170CAHE3_A/H offers reduced surge capacity in a smaller package, while SMCJ170AHE3_A/H provides identical clamping performance but demands strict polarity orientation-making SMCJ170CAHM3_A/H the preferred choice for floating, AC-coupled, or polarity-agnostic protection zones.

Availability

SMCJ170CAHM3_A/H is available at Aetrix Electronics and suitable for automotive electronics, industrial automation systems, and telecommunications infrastructure requiring stable component supply with AEC-Q101 qualification and halogen-free compliance.

Supply support for SMCJ170CAHM3_A/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 SMCJ series is engineered for high-energy transient suppression in harsh environments, targeting automotive, industrial, and telecom applications where robustness against lightning, ESD, and inductive switching is mission-critical.

FAQ

What does the "CA" suffix indicate in SMCJ170CAHM3_A/H?

The "CA" suffix denotes a bidirectional configuration, meaning the SMCJ170CAHM3_A/H provides symmetrical clamping in both polarities without requiring polarity-aware placement. This differs from unidirectional variants (e.g., SMCJ170A) that feature a cathode band and conduct only in reverse bias. Bidirectional operation makes SMCJ170CAHM3_A/H ideal for AC signal lines, differential buses, and floating power domains where voltage polarity reversal is possible.

Is SMCJ170CAHM3_A/H qualified for automotive use?

Yes, SMCJ170CAHM3_A/H is AEC-Q101 qualified, as confirmed by Vishay's ordering code structure: the "HM3" suffix indicates halogen-free, RoHS-compliant construction with full AEC-Q101 stress testing. This qualification covers temperature cycling, highly accelerated life testing (HALT), and mechanical shock-ensuring suitability for under-hood and chassis-mounted automotive electronics where reliability under thermal and vibration stress is mandatory.

What is the maximum clamping voltage of SMCJ170CAHM3_A/H and how is it measured?

The maximum clamping voltage (V_C) of SMCJ170CAHM3_A/H is 275 V, measured at a peak pulse current (I_PPM) of 5.5 A using a standardized 10/1000 µs double-exponential surge waveform. This value represents the upper limit of voltage seen by protected circuitry during worst-case transient events and is validated per ANSI/IEEE C62.35. It ensures downstream components experience no more than 275 V stress even under full-rated surge conditions.

How does the HM3 suffix differ from M3 or HE3 in SMCJ170CAHM3_A/H?

The "HM3" suffix in SMCJ170CAHM3_A/H specifies halogen-free, RoHS-compliant construction *and* AEC-Q101 qualification-distinguishing it from "M3" (halogen-free + RoHS, commercial grade only) and "HE3" (RoHS-compliant + AEC-Q101, but not halogen-free). This dual certification makes SMCJ170CAHM3_A/H compliant with both environmental regulations (e.g., EU RoHS, JEITA-MITI) and automotive reliability standards, critical for Tier 1 suppliers and OEMs with strict material declarations.

Can SMCJ170CAHM3_A/H replace SMCJ170AHE3_A/H in an existing design?

No direct replacement is assured: SMCJ170CAHM3_A/H is bidirectional, while SMCJ170AHE3_A/H is unidirectional with a defined cathode. Swapping them requires verifying circuit polarity, grounding scheme, and transient directionality. If the original design relies on forward conduction blocking or uses DC bias, SMCJ170AHE3_A/H may be necessary. For AC-coupled or floating nodes, SMCJ170CAHM3_A/H offers greater flexibility-but layout review and surge testing are required before substitution.