Vishay General Semiconductor - Diodes Division 3KASMC28AHM3_B/H

Overview

3KASMC28AHM3_B/H from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor (TVS) in SMC (DO-214AB) package, rated for 3000 W peak pulse power (10/1000 μs), 28 V stand-off voltage (VWM), and 45.4 V maximum clamping voltage (VC) at 66.1 A IPPM. It operates up to TJ = 185 °C and is halogen-free, RoHS-compliant, and AEC-Q101 qualified - designed for automotive power line and sensor signal protection.

For engineers reviewing the 3KASMC28AHM3_B/H datasheet, 3KASMC28AHM3_B/H pinout, 3KASMC28AHM3_B/H application, or 3KASMC28AHM3_B/H equivalent, key selection criteria include unidirectional clamping performance under 10/1000 μs surge, thermal stability at 185 °C junction temperature, AEC-Q101 qualification status, and SMC package compatibility with high-reliability automotive PCB layouts.

Technical Context

This TVS diode uses passivated anisotropic rectifier technology to deliver stable breakdown behavior and low incremental surge resistance. Its 185 °C maximum junction temperature and MSL Level 1 rating support reflow soldering at 260 °C peak, enabling use in under-hood automotive modules and industrial motor drives where thermal cycling reliability is critical.

The device exhibits 0.089 %/°C temperature coefficient of VBR and 77.5 °C/W junction-to-ambient thermal resistance when mounted on minimum recommended pads. Clamping occurs within picoseconds, with VF = 3.5 V at 100 A forward surge, ensuring robust protection against inductive switching transients without compromising system-level voltage margins.

Key Specifications

Pinout & Package

Package: SMC (DO-214AB), molded case meeting UL 94 V-0 flammability rating; matte tin-plated leads compliant with J-STD-002 and JESD 22-B102; cathode indicated by color band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ28AHE3_A/H and SMCJ28AHE3_A/H, the 3KASMC28AHM3_B/H uniquely combines 3000 W surge capability, 185 °C operation, halogen-free construction, and formal AEC-Q101 qualification - making it the only option among the three certified for under-hood automotive deployment with full material compliance.

Availability

3KASMC28AHM3_B/H is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, and telecom power feeding systems requiring stable component supply, long-term lifecycle assurance, and full AEC-Q101 traceability.

Supply support for 3KASMC28AHM3_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, TVS devices, and optoelectronics with emphasis on high-reliability, high-temperature, and automotive-grade performance.

The 3KASMC series was developed specifically for AEC-Q101-compliant transient suppression in demanding automotive power domains, emphasizing thermal robustness, surge endurance, and halogen-free compliance for next-generation E/E architectures.

FAQ

What is the clamping voltage of the 3KASMC28AHM3_B/H at its rated peak pulse current?

The 3KASMC28AHM3_B/H has a maximum clamping voltage (VC) of 45.4 V at 66.1 A peak pulse current (IPPM), measured using the standardized 10/1000 μs double-exponential waveform. This value is guaranteed across the full operating temperature range and forms the basis for downstream circuit protection margin calculations in 24 V automotive systems.

Is the 3KASMC28AHM3_B/H qualified to AEC-Q101, and what tests does that include?

Yes, the 3KASMC28AHM3_B/H is AEC-Q101 qualified. This includes stress testing per the AEC-Q101 standard such as high-temperature reverse bias (HTRB), temperature cycling (TCT), highly accelerated stress test (HAST), and unbiased highly accelerated stress test (uHAST). Qualification applies specifically to the HM3 suffix variant and is documented in Vishay's official AEC-Q101 certificate for the 3KASMC family.

What does the "HM3" suffix indicate in 3KASMC28AHM3_B/H?

The "HM3" suffix in 3KASMC28AHM3_B/H denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification. It distinguishes this variant from HE3 (RoHS-compliant and AEC-Q101 qualified but not halogen-free) and confirms compliance with automotive material restrictions including IMDS reporting requirements for bromine, chlorine, and other halogens.

Can the 3KASMC28AHM3_B/H replace the older 3KASMC28AHE3_B/H in an existing design?

Yes, the 3KASMC28AHM3_B/H is a direct replacement for 3KASMC28AHE3_B/H in terms of electrical specs, package, and pinout. The HM3 version adds halogen-free compliance while retaining identical VWM, VBR, VC, and surge ratings. No PCB layout or schematic changes are needed, though material declaration updates may be required for automotive audits.

What is the thermal resistance of the 3KASMC28AHM3_B/H, and how does it affect board layout?

The 3KASMC28AHM3_B/H has a typical junction-to-ambient thermal resistance (R_θJA) of 77.5 °C/W when mounted on the minimum recommended pad layout per Vishay's datasheet. To maintain TJ ≤ 185 °C under sustained 6.0 W power dissipation, designers must ensure adequate copper area and avoid thermal isolation - especially critical in high-temperature under-hood placements.