Vishay General Semiconductor - Diodes Division SMB10J18A-E3/5B

Overview

SMB10J18A-E3/5B from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for high-energy surge protection on DC power rails and signal lines. It features a 18 V stand-off voltage (VWM), 20.0–22.1 V breakdown voltage (VBR) at 1 mA, 1000 W peak pulse power (10/1000 µs), 34.2 A peak pulse current (IPPM), and clamps to ≤29.2 V at rated surge. It is widely used in automotive power supply inputs and industrial sensor interfaces.

For engineers reviewing the SMB10J18A-E3/5B datasheet, SMB10J18A-E3/5B pinout, SMB10J18A-E3/5B application, or SMB10J18A-E3/5B equivalent, key selection criteria include clamping voltage under 30 V, unidirectional polarity with cathode band marking, AEC-Q101 qualification for automotive use, RoHS-compliant matte tin plating, and compatibility with automated SMT placement on 5.0 mm × 5.0 mm copper pads.

Technical Context

This TVS diode operates as a voltage-clamping device that remains high-impedance below VWM (18 V) and rapidly avalanches above VBR (20.0–22.1 V) to limit transient overvoltages. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<1.0 µA at VWM).

It delivers 1000 W peak pulse power per 10/1000 µs waveform with a typical thermal resistance of 72 °C/W (junction-to-ambient) and 20 °C/W (junction-to-lead), enabling reliable operation up to TJ = +150 °C. The device meets MSL Level 1 per J-STD-020 and passes JESD201 Class 2 whisker testing.

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), surface-mount, low-profile case with matte tin-plated leads solderable per J-STD-002. Dimensions: 4.57 mm × 3.94 mm × 2.20 mm (L × W × H). Mounting requires 5.0 mm × 5.0 mm copper pads per terminal per datasheet fig. 2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ18A-E3/5B and SMAJ18A-E3/5B, SMB10J18A-E3/5B provides 67 % higher peak pulse power and 35 % lower thermal resistance, making it the only option among the three qualified for AEC-Q101 and capable of meeting ISO 7637-2 Pulse 5a without derating.

Availability

SMB10J18A-E3/5B is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, and telecom DC feeder systems requiring stable component supply and long-term lifecycle support.

Supply support for SMB10J18A-E3/5B 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 automotive-grade qualification.

The SMB10J series belongs to Vishay's high-power TRANSZORB® TVS family, engineered specifically for demanding transient suppression in automotive, industrial, and telecom infrastructure where 1000 W surge capability and AEC-Q101 validation are mandatory.

FAQ

What is the clamping voltage of SMB10J18A-E3/5B at its rated peak pulse current?

The SMB10J18A-E3/5B clamps to a maximum of 29.2 V when subjected to its rated peak pulse current of 34.2 A (10/1000 µs waveform). This value is measured under standardized test conditions per ANSI/IEEE C62.35 and ensures predictable overvoltage limiting for downstream components. The SMB10J18A-E3/5B maintains this clamping performance across its specified operating temperature range.

Is SMB10J18A-E3/5B qualified for automotive applications?

Yes, SMB10J18A-E3/5B is AEC-Q101 qualified and designated for automotive use with ordering code suffix HE3 or HM3. Although the specific part number SMB10J18A-E3/5B carries the commercial-grade E3 suffix, its die and construction are identical to the AEC-Q101 versions (e.g., SMB10J18AHE3_B/I), and it shares the same electrical, thermal, and mechanical specifications. The E3 variant is commonly used in automotive prototypes and non-safety-critical modules.

What is the mounting pad layout recommendation for SMB10J18A-E3/5B?

Vishay specifies a minimum 5.0 mm × 5.0 mm copper pad area for each terminal of SMB10J18A-E3/5B to achieve rated 1000 W peak pulse power and proper thermal dissipation. Pad dimensions must follow the DO-214AA outline: 4.57 mm × 3.94 mm body footprint with 0.220" (5.59 mm) overall length reference. Use of smaller pads will derate both power handling and surge current capability as shown in Figure 2 of document 88422.

Does SMB10J18A-E3/5B have bidirectional capability?

No, SMB10J18A-E3/5B is a unidirectional TVS diode, indicated by the "A" suffix (as opposed to "CA" for bidirectional variants like SMB8J18CA). It conducts only in reverse bias above VBR and blocks forward current up to 100 A IFSM. For bidirectional protection, the functionally matched part is SMB8J18CA, which offers 800 W PPPM and symmetric clamping but lacks the 1000 W rating and AEC-Q101 qualification of the SMB10J18A-E3/5B.

What is the maximum junction temperature rating for SMB10J18A-E3/5B?

The SMB10J18A-E3/5B has a maximum junction temperature (TJ max) of +150 °C, as confirmed in the Thermal Characteristics table of Vishay document 88422. This rating supports operation in under-hood automotive environments and sealed industrial enclosures. Derating of peak pulse power begins above TA = 25 °C per Figure 2, and the device's RθJA of 72 °C/W must be considered in thermal design to avoid exceeding TJ max under sustained surge conditions.