Vishay General Semiconductor - Diodes Division SMCJ70AHM3/H

Overview

SMCJ70AHM3/H from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMC (DO-214AB) package, designed for high-energy surge protection with 70 V standoff voltage, 113 V clamping voltage at 13.3 A peak pulse current, and 1500 W peak pulse power rating. It protects MOSFETs, ICs, and sensor signal lines in automotive power systems and industrial control interfaces.

For engineers reviewing the SMCJ70AHM3/H datasheet, SMCJ70AHM3/H pinout, SMCJ70AHM3/H application, or SMCJ70AHM3/H equivalent, key selection criteria include unidirectional polarity, AEC-Q101 qualification, halogen-free RoHS compliance, and thermal resistance of 75 °C/W junction-to-ambient under standard pad layout.

Technical Context

This TVS diode operates as a clamping device triggered by reverse-biased avalanche breakdown above its 70 V stand-off voltage (VWM), delivering sub-nanosecond response to transients such as inductive load switching and ESD events. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<1.0 μA at VWM).

Rated for 1500 W peak pulse power (10/1000 μs waveform), it sustains 13.3 A IPPM while clamping to ≤113 V, with a temperature coefficient of VBR at +0.105 %/°C. Junction temperature range spans –55 °C to +150 °C, supporting under-hood automotive environments.

Key Specifications

Pinout & Package

Package: SMC (DO-214AB), surface-mount, halogen-free, matte tin-plated leads solderable per J-STD-002. Cathode indicated by band on body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMCJ70AHM3/H, SMAJ70AHE3/A offers reduced surge handling in a smaller footprint, while SMCJ70A-M3/57T provides identical protection performance without automotive qualification-making SMCJ70AHM3/H the sole option when AEC-Q101 compliance and 1500 W capability are both required.

Availability

SMCJ70AHM3/H is available at Aetrix Electronics and suitable for automotive power distribution, industrial sensor interface protection, and telecom power input stage applications requiring stable component supply and long-term lifecycle assurance.

Supply support for SMCJ70AHM3/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 and application-specific performance.

The SMCJ series targets high-energy transient suppression in harsh environments; SMCJ70AHM3/H specifically addresses automotive and industrial needs where AEC-Q101 qualification, halogen-free construction, and 1500 W surge capacity are mandatory.

FAQ

What is the clamping voltage of SMCJ70AHM3/H at its rated peak pulse current?

The SMCJ70AHM3/H clamps to a maximum of 113 V at its rated peak pulse current of 13.3 A (10/1000 μs waveform). This value is measured under standardized test conditions and defines the upper voltage limit imposed on protected circuitry during surge events. The clamping performance is guaranteed across the full operating temperature range and forms the basis for downstream component voltage derating in designs using the SMCJ70AHM3/H.

Is SMCJ70AHM3/H qualified for automotive applications?

Yes, SMCJ70AHM3/H is AEC-Q101 qualified, as confirmed by the "HM3" suffix denoting halogen-free, RoHS-compliant, and automotive-grade construction. It has undergone stress testing including temperature cycling, highly accelerated life testing (HALT), and surge endurance validation per AEC-Q101 Rev D. This qualification makes the SMCJ70AHM3/H suitable for use in engine control units, body electronics, and ADAS power domains where reliability under thermal and electrical stress is critical.

What does the "H" in SMCJ70AHM3/H indicate in the ordering code?

The "H" in SMCJ70AHM3/H specifies the preferred package code for 7-inch diameter plastic tape and reel delivery, containing 850 units per reel. This packaging format is optimized for high-speed SMT placement equipment and aligns with industry-standard feeder compatibility. The full ordering designation confirms halogen-free (HM3) construction, AEC-Q101 qualification, and tape-and-reel logistics-ensuring consistent supply chain traceability and assembly readiness for the SMCJ70AHM3/H.

How does the thermal resistance of SMCJ70AHM3/H affect PCB layout?

The SMCJ70AHM3/H has a typical junction-to-ambient thermal resistance (RθJA) of 75 °C/W when mounted on 8.0 mm × 8.0 mm copper pads per terminal. To maintain safe junction temperatures under sustained power dissipation or repeated surges, designers must allocate sufficient copper area and consider thermal vias beneath the SMC pads. Reducing pad size or omitting thermal relief increases RθJA, risking thermal runaway during high-duty-cycle transients-so adherence to the recommended layout is essential for reliable operation of the SMCJ70AHM3/H.

Can SMCJ70AHM3/H be used in bidirectional configurations?

No, SMCJ70AHM3/H is a unidirectional TVS diode, as indicated by the "A" suffix (versus "CA" for bidirectional variants like SMCJ70CA). Its cathode band marks the polarity-sensitive terminal, and it conducts only during reverse-biased overvoltage events. For AC-coupled or symmetrical transient protection (e.g., RS-485 bus lines), a bidirectional part such as SMCJ70CA must be selected instead. Using SMCJ70AHM3/H in bidirectional roles risks forward conduction failure and inadequate protection-confirming that SMCJ70AHM3/H is strictly for DC rail or single-polarity signal line protection.