Vishay General Semiconductor - Diodes Division 1.5SMC30A-M3/57T

Overview

1.5SMC30A-M3/57T from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode designed for robust overvoltage protection in power and signal lines. It features a 30 V breakdown voltage (V_BR = 28.5–31.5 V at 1.0 mA), 25.6 V stand-off voltage (V_WM), clamps transients to ≤41.4 V at 36.2 A peak pulse current, and delivers 1500 W peak pulse power with a 10/1000 μs waveform - deployed in automotive sensor interfaces and industrial power supply rails.

For engineers reviewing the 1.5SMC30A-M3/57T datasheet, 1.5SMC30A-M3/57T pinout, 1.5SMC30A-M3/57T application, or 1.5SMC30A-M3/57T equivalent, key selection criteria include unidirectional polarity, SMC (DO-214AB) package compatibility, 150 °C maximum junction temperature, low incremental surge resistance, and halogen-free RoHS compliance per M3 suffix.

Technical Context

This TVS diode operates as a clamping device that remains non-conductive below its reverse stand-off voltage (25.6 V), then rapidly avalanches above its breakdown threshold (28.5–31.5 V) to limit transient energy. Its glass-passivated junction ensures stable leakage (<1.0 μA at V_WM) and fast response time (<1.0 ns).

Thermal performance is defined by R_θJA = 75 °C/W (junction-to-ambient, on recommended 8.0 mm × 8.0 mm copper pads) and R_θJL = 15 °C/W (junction-to-leads), supporting reliable operation up to 150 °C junction temperature under repetitive surge conditions with 0.01% duty cycle.

Key Specifications

Pinout & Package

Package: SMC (DO-214AB) - molded plastic case with cathode band marking; terminals are matte tin-plated leads solderable per J-STD-002 and JESD22-B102; polarity indicated by cathode band on unidirectional devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1.5SMC30A-M3/57T, SMBJ30A-E3/52 trades peak power and thermal margin for compact size, while 1.5KE30A-T maintains identical clamping behavior but eliminates SMT compatibility - making 1.5SMC30A-M3/57T optimal for new automotive and industrial SMT designs needing full 1500 W protection in DO-214AB form factor.

Availability

1.5SMC30A-M3/57T is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial power supply inputs, and telecom line protection requiring stable component supply, halogen-free compliance, and AEC-Q101-aligned reliability.

Supply support for 1.5SMC30A-M3/57T 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 reliability, efficiency, and application-specific optimization.

The 1.5SMC Series was engineered for high-power transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where robustness against lightning, load dump, and ESD is mission-critical.

FAQ

What is the maximum clamping voltage of the 1.5SMC30A-M3/57T under peak pulse conditions?

The 1.5SMC30A-M3/57T has a maximum clamping voltage (V_C) of 41.4 V when subjected to its rated peak pulse current of 36.2 A using a 10/1000 μs waveform. This value is guaranteed per the Vishay datasheet and reflects worst-case performance at T_A = 25 °C with proper PCB pad layout (8.0 mm × 8.0 mm copper). The 1.5SMC30A-M3/57T maintains this clamping performance across its specified operating temperature range.

Is the 1.5SMC30A-M3/57T suitable for automotive applications?

Yes - the 1.5SMC30A-M3/57T is halogen-free and RoHS-compliant (M3 suffix), meets MSL Level 1, and is qualified to AEC-Q101 when ordered with HE3 or HM3 suffixes. While the base 1.5SMC30A-M3/57T part itself is commercial-grade, its construction (glass-passivated junction, 150 °C T_J max, robust surge rating) aligns with automotive subsystem requirements such as body control modules and sensor interfaces. For certified automotive use, specify HM3 suffix variants like 1.5SMC30AHM3_A/H.

What does the "M3/57T" suffix indicate in 1.5SMC30A-M3/57T?

The "M3" suffix denotes halogen-free, RoHS-compliant construction with JESD201 Class 2 whisker resistance; "57T" specifies packaging in 7-inch diameter plastic tape-and-reel format with 850 units per reel. This ordering code ensures consistent material compliance and automated placement compatibility. The 1.5SMC30A-M3/57T is distinct from E3-suffix versions (RoHS-compliant but not halogen-free) and HE3/HM3 variants (AEC-Q101 qualified).

How does the 1.5SMC30A-M3/57T compare to bidirectional TVS diodes like 1.5SMC30CA?

The 1.5SMC30A-M3/57T is unidirectional and intended for DC line protection where polarity is fixed (e.g., +24 V rail to ground); it offers lower leakage (<1.0 μA at 25.6 V) and tighter V_BR tolerance than its bidirectional counterpart 1.5SMC30CA. The 1.5SMC30CA supports AC or floating lines but exhibits higher leakage and symmetric clamping in both directions. Use 1.5SMC30A-M3/57T when protecting polarized circuits with strict leakage budgets.

What PCB layout guidance applies to the 1.5SMC30A-M3/57T for optimal thermal and surge performance?

For rated 1500 W pulse handling, mount the 1.5SMC30A-M3/57T on minimum 0.31" × 0.31" (8.0 mm × 8.0 mm) copper pads per terminal, per Vishay's datasheet Fig. 2. Avoid thermal relief on pads to minimize R_θJA; use internal ground/power planes for heat spreading. Keep traces short and wide between the 1.5SMC30A-M3/57T and protected node to reduce inductance and preserve clamping speed.