Vishay General Semiconductor - Diodes Division 1.5SMC51AHE3_A/I

Overview

1.5SMC51AHE3_A/I from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMC (DO-214AB) package, rated for 51 V breakdown voltage (V_BR = 48.5–53.6 V at I_T = 1.0 mA), 70.1 V maximum clamping voltage (V_C) at 21.4 A peak pulse current, and 1500 W peak pulse power (10/1000 µs). It protects automotive-grade power rails and signal lines against ESD, lightning surges, and inductive switching transients.

For engineers reviewing the 1.5SMC51AHE3_A/I datasheet, 1.5SMC51AHE3_A/I pinout, 1.5SMC51AHE3_A/I application, or 1.5SMC51AHE3_A/I equivalent, key selection criteria include its AEC-Q101 qualification, 43.6 V stand-off voltage (V_WM), <1.0 µA reverse leakage at V_WM, low thermal resistance (R_θJL = 15 °C/W), and compatibility with automated SMT assembly on standard PCB pad layouts.

Technical Context

This TVS diode operates as a unidirectional clamping device with cathode-band polarity marking, leveraging a glass-passivated silicon junction for fast response (<1 ns) and stable breakdown characteristics. Its 1500 W surge rating is defined under standardized 10/1000 µs waveform conditions with 0.01% duty cycle, and it maintains clamping performance across -65 °C to +150 °C operating junction temperature range.

The device is thermally optimized for surface-mount applications: R_θJA = 75 °C/W (on 8.0 mm × 8.0 mm copper pads), R_θJL = 15 °C/W, and meets J-STD-020 MSL Level 1 (peak reflow ≤260 °C). Its AEC-Q101 qualification confirms suitability for automotive electronics where reliability under thermal cycling and mechanical stress is critical.

Key Specifications

Pinout & Package

Package: SMC (DO-214AB), surface-mount, unidirectional configuration with cathode band marking on one end. Dimensions: 8.13 mm × 6.22 mm × 2.62 mm (L × W × H); terminals are matte tin-plated, solderable per J-STD-002 and JESD 22-B102.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ51A-E3/57T and 1.5KE51A, the 1.5SMC51AHE3_A/I uniquely combines AEC-Q101 qualification, 1500 W surge capacity, and SMC package compatibility with high-volume SMT assembly-making it the preferred choice for automotive and industrial power rail protection where reliability and process scalability are mandatory.

Availability

1.5SMC51AHE3_A/I is available at Aetrix Electronics and suitable for automotive power systems, industrial sensor interfaces, telecom DC inputs, and consumer USB-C port protection requiring stable component supply and long-term lifecycle support.

Supply support for 1.5SMC51AHE3_A/I 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 automotive-grade validation.

The 1.5SMC Series was designed specifically for high-power transient suppression in demanding environments-including automotive, industrial, and telecom-where robustness against repetitive surges and extended temperature operation are essential.

FAQ

What is the clamping voltage of the 1.5SMC51AHE3_A/I under full 1500 W surge conditions?

The 1.5SMC51AHE3_A/I clamps to a maximum of 70.1 V when subjected to its rated 21.4 A peak pulse current (10/1000 µs waveform), which corresponds to the full 1500 W surge power. This value is measured per Figure 1 and Table 1 in the Vishay datasheet 88303 and is guaranteed across the operating temperature range of -65 °C to +150 °C.

Is the 1.5SMC51AHE3_A/I AEC-Q101 qualified, and what does that mean for automotive use?

Yes, the 1.5SMC51AHE3_A/I is AEC-Q101 qualified, as indicated by the "HE3" suffix and confirmed in the ordering information table (page 3) and features list. This qualification validates its reliability under automotive-specific stress tests-including temperature cycling, high-temperature reverse bias, and mechanical shock-making it suitable for under-hood and chassis-mounted applications where failure is not acceptable.

What is the standoff voltage (V_WM) of the 1.5SMC51AHE3_A/I, and how does it relate to system operating voltage?

The 1.5SMC51AHE3_A/I has a maximum standoff voltage V_WM of 43.6 V, meaning it remains in high-impedance state below this voltage. For reliable operation, the system's normal DC operating voltage must be ≤43.6 V-e.g., it is appropriate for 36 V nominal automotive systems or 42 V maximum bus rails, providing margin against ripple and tolerance drift before clamping initiates.

Does the 1.5SMC51AHE3_A/I have polarity marking, and how is it identified on the package?

Yes, the 1.5SMC51AHE3_A/I is unidirectional and features a visible cathode band on the SMC (DO-214AB) package body, located near the cathode terminal. As shown in the package outline drawing (page 5), this band aligns with the cathode end-critical for correct orientation during PCB layout and assembly to ensure proper clamping direction toward the protected rail.

What is the thermal resistance from junction to leads (R_θJL) for the 1.5SMC51AHE3_A/I, and why does it matter?

The 1.5SMC51AHE3_A/I has a typical junction-to-leads thermal resistance R_θJL of 15 °C/W, per the Thermal Characteristics table (page 3). This low value enables efficient heat transfer from the silicon junction directly into the PCB copper traces via the leads-critical for sustaining repetitive surge events and maintaining long-term reliability in high-temperature environments like engine control units.