Vishay General Semiconductor - Diodes Division 3KASMC28HE3_A/H

Overview

3KASMC28HE3_A/H from Vishay General Semiconductor is a unidirectional surface-mount PAR® Transient Voltage Suppressor (TVS) diode designed for high-energy surge clamping in automotive and industrial power rails. It delivers 3000 W peak pulse power (10/1000 µs), clamps at 45.4 V under 66.1 A surge current, and operates up to 185 °C junction temperature - enabling robust protection of MOSFETs and ICs against inductive switching transients in engine control units.

For engineers reviewing the 3KASMC28HE3_A/H datasheet, 3KASMC28HE3_A/H pinout, 3KASMC28HE3_A/H application, or 3KASMC28HE3_A/H equivalent, this page provides verified electrical specs, DO-214AB package details, AEC-Q101 qualification status, thermal resistance data, and real-world protection use cases - all confirmed from Vishay's official document 89962 (Rev. 05-Mar-13).

Technical Context

This TVS diode uses passivated anisotropic rectifier technology optimized for high-temperature stability and low incremental surge resistance. Its unidirectional polarity and 31.1–34.4 V breakdown voltage range (at 1 mA) ensure precise clamping above system operating voltage while maintaining low leakage (<1 µA at 28 V, 25 °C).

It meets MSL Level 1 per J-STD-020 with 260 °C lead-free reflow compatibility, and its DO-214AB (SMC) package supports high-power dissipation (6.0 W on infinite heatsink) with R_θJA = 77.5 °C/W and R_θJL = 18.3 °C/W - critical for thermally constrained automotive PCB layouts.

Key Specifications

Pinout & Package

Package: DO-214AB (SMC), surface-mount, matte tin-plated leads, cathode indicated by color band. Complies with UL 94 V-0 and JESD 22-B102 solderability standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ28A and SMCJ28A, the 3KASMC28HE3_A/H delivers superior thermal robustness (185 °C vs. ≤175 °C), guaranteed AEC-Q101 compliance, and tighter V_BR tolerance - making it the preferred choice for production automotive ECUs and high-reliability industrial drives.

Availability

3KASMC28HE3_A/H is available at Aetrix Electronics and suitable for automotive engine control units, industrial motor drive DC buses, telecom power supply inputs, and body control modules requiring stable component supply and long-term lifecycle support.

Supply support for 3KASMC28HE3_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, and protection devices with emphasis on high-reliability, high-temperature, and automotive-grade performance.

The 3KASMC series is part of Vishay's PAR® TVS platform, engineered specifically for AEC-Q101-compliant transient suppression in harsh-environment automotive and industrial power systems - delivering stable clamping under sustained thermal stress.

FAQ

What is the exact breakdown voltage range for 3KASMC28HE3_A/H?

The 3KASMC28HE3_A/H has a specified breakdown voltage (V_BR) range of 31.1 V to 34.4 V at 1 mA test current, per Vishay document 89962. This range ensures consistent turn-on behavior across production lots and guarantees clamping activation before reaching the 36 V maximum rating of common automotive-grade regulators and microcontrollers. The 3KASMC28HE3_A/H maintains this specification over its full operating temperature range.

Is 3KASMC28HE3_A/H qualified for automotive applications?

Yes, the 3KASMC28HE3_A/H is explicitly AEC-Q101 qualified, as confirmed in the "MECHANICAL DATA" section of Vishay document 89962. It undergoes stress testing including high-temperature operating life, temperature cycling, and humidity bias HAST - meeting automotive reliability requirements for under-hood and chassis-mounted electronics. The 3KASMC28HE3_A/H also complies with MSL Level 1 for lead-free assembly.

What package does 3KASMC28HE3_A/H use, and what are its key mechanical features?

The 3KASMC28HE3_A/H uses the DO-214AB (SMC) surface-mount package, with dimensions of 7.75 mm × 6.22 mm × 2.62 mm (L × W × H). Key features include matte tin-plated leads compliant with J-STD-002 and JESD 22-B102, UL 94 V-0 molding compound, and a cathode identification band. The 3KASMC28HE3_A/H's pad layout follows Vishay's recommended minimum footprint for optimal thermal and mechanical reliability.

How does the clamping performance of 3KASMC28HE3_A/H compare to its stand-off voltage?

The 3KASMC28HE3_A/H has a stand-off voltage (V_WM) of 28 V and clamps at 45.4 V when subjected to its rated 66.1 A surge current (10/1000 µs waveform). This 17.4 V margin ensures the device remains fully non-conductive during normal operation while providing rapid, low-overshoot clamping during transients - critical for protecting 36 V-tolerant components without false triggering. The 3KASMC28HE3_A/H achieves this via low incremental surge resistance.

What is the maximum junction temperature rating for 3KASMC28HE3_A/H, and why does it matter?

The 3KASMC28HE3_A/H is rated for a maximum junction temperature (T_J) of +185 °C, significantly exceeding standard industrial TVS diodes (typically 150–175 °C). This enables reliable operation in high-ambient locations such as engine compartments, power inverters, and enclosed industrial enclosures. The 3KASMC28HE3_A/H's 185 °C rating eliminates thermal derating concerns in designs where PCB copper area is limited or airflow is restricted.