Taiwan Semiconductor Corporation SMBJ90

Overview

SMBJ90 from Taiwan Semiconductor is a unidirectional 600W surface-mount transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power rails and signal lines. It features a 90V working stand-off voltage (VWM), 100–122V breakdown voltage (VBR) at 1mA test current, and clamps transients to ≤160V at 3.9A peak impulse current (IPP), making it suitable for automotive load-dump and ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance.

For engineers reviewing the SMBJ90 datasheet, SMBJ90 pinout, SMBJ90 application, or SMBJ90 equivalent, key selection criteria include clamping voltage under rated IPP, forward voltage (VF = 3.5V @ 50A), junction-to-ambient thermal resistance (55°C/W), and DO-214AA (SMB) package compatibility with automated SMT assembly.

Technical Context

The SMBJ90 operates as a unidirectional avalanche diode, leveraging glass-passivated PN junction technology to achieve sub-1ps response time and low leakage (<1μA above 10V). Its 600W peak pulse power rating (10/1000μs waveform) is derated linearly above 25°C ambient per Fig.2, with maximum junction temperature limited to +150°C.

It is optimized for single-die, cathode-banded configuration in DO-214AA (SMB) package, supporting bidirectional variants only with "C" or "CA" suffixes - the SMBJ90 itself is strictly unidirectional and polarity-marked. Thermal performance is defined by R_θJC = 10°C/W and R_θJA = 55°C/W.

Key Specifications

Pinout & Package

Package: DO-214AA (SMB), surface-mount, matte tin-plated leads, polarity indicated by cathode band. Weight: 0.090 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ90, SMAJ90A offers bidirectional capability in a smaller package but sacrifices 33% peak power and thermal robustness, while SMCJ90A delivers superior surge endurance and cooling at the cost of board space - SMBJ90 balances 600W capability, SMB footprint, and unidirectional precision for cost-sensitive automotive and industrial power inputs.

Availability

SMBJ90 is available at Aetrix Electronics and suitable for automotive ECU protection, industrial PLC I/O hardening, and LED driver input stage design requiring stable component supply and full traceability through J-STD-020 Level 1 handling.

Supply support for SMBJ90 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, and MOSFETs for industrial and automotive markets.

The SMBJ series was developed to deliver high-power, surface-mount TVS protection in compact DO-214AA packages for automotive power distribution modules and industrial control systems demanding ISO 7637-2 compliance and J-STD-020 Level 1 manufacturability.

FAQ

What is the clamping voltage of SMBJ90 under its rated peak impulse current?

The SMBJ90 has a maximum clamping voltage (VC) of 160 V when subjected to its rated peak impulse current (IPP) of 3.9 A under the standard 10/1000 µs waveform. This value is measured at TA = 25°C and defines the upper voltage limit imposed on protected circuitry during surge events. The SMBJ90 maintains this clamping performance across its operational junction temperature range.

Is SMBJ90 unidirectional or bidirectional, and how is polarity identified?

SMBJ90 is a unidirectional TVS diode, with polarity marked by a cathode band on the DO-214AA (SMB) package body. The banded end is the cathode and must be connected toward the system ground or low-impedance return path. Bidirectional variants require "C" or "CA" suffixes (e.g., SMBJ90C), which are distinct part numbers - SMBJ90 itself conducts only in reverse bias and blocks forward current up to VF = 3.5 V @ 50 A.

Does SMBJ90 meet automotive transient immunity standards?

Yes, SMBJ90 meets ISO 7637-2 Pulse 1 (inductive load disconnect), Pulse 2a (switching off parallel loads), Pulse 2b (supply interruption), Pulse 3a (capacitive coupled EFT), and Pulse 3b (inductive coupled EFT). Its 600W peak pulse power rating, fast <1.0 ps response, and specified clamping behavior under standardized waveforms make it suitable for front-end protection in automotive ECUs, body control modules, and lighting drivers.

What is the maximum steady-state power dissipation for SMBJ90 at room temperature?

The SMBJ90 has a steady-state power dissipation (PD) rating of 3 W at TA = 25°C. This value applies only to continuous DC forward conduction - in normal TVS operation, the device remains in high-impedance blocking mode until a transient exceeds VBR. Under surge conditions, it relies on its 600W non-repetitive peak pulse rating, not PD, and must be thermally derated per Fig.2 above 25°C ambient.

Can SMBJ90 be used in place of SMBJ90A, and what is the key difference?

No - SMBJ90 and SMBJ90A are not interchangeable without circuit review. SMBJ90A has tighter VBR tolerance (100–111 V vs. 100–122 V), lower clamping voltage (146 V vs. 160 V at rated IPP), and identical VWM (90 V). The SMBJ90A is optimized for applications requiring more precise breakdown and lower let-through voltage, while SMBJ90 provides broader tolerance and higher surge margin. Both share the same DO-214AA package and unidirectional function.