Taiwan Semiconductor Corporation SMAJ7.0H

Overview

SMAJ7.0H from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for primary-side overvoltage protection in DC power rails. It features a 7.78–9.51 V breakdown voltage, 13.3 V clamping voltage at 200 A peak pulse current, and 400 W peak pulse power (10/1000 µs waveform), making it suitable for automotive-grade SMPS input protection per ISO 7637-2 Pulse 1/2a/2b/3a/3b.

For engineers reviewing the SMAJ7.0H datasheet, SMAJ7.0H pinout, SMAJ7.0H application, or SMAJ7.0H equivalent, key selection criteria include its AEC-Q101 qualification, DO-214AC (SMA) package compatibility with automated placement, sub-1 ps response time, and ≤7 µA reverse leakage at 7 V working stand-off voltage.

Technical Context

The SMAJ7.0H operates as a unidirectional avalanche diode with glass-passivated junction, optimized for fast clamping of transient surges on low-voltage DC lines. Its 13.3 V clamping voltage at 200 A ensures robust protection of downstream MOSFETs or controllers without exceeding safe voltage margins.

It meets ISO 7637-2 test requirements for automotive electronics-including Pulse 1 (inductive load dump), Pulse 2a (sudden load disconnect), and Pulse 3a/3b (switching noise)-and supports operating junction temperatures from –55 °C to +150 °C with moisture sensitivity level 1 (J-STD-020).

Key Specifications

Pinout & Package

Package: DO-214AC (SMA), surface-mount, single-diode configuration with cathode band marking. Matte tin-plated leads meet J-STD-002 solderability; weight ≈0.060 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ7.0A and SMBJ7.0H, the SMAJ7.0H offers balanced clamping performance and compact DO-214AC packaging ideal for space-constrained automotive and industrial PCBs where 400 W surge capacity suffices and AEC-Q101 validation is mandatory.

Availability

SMAJ7.0H is available at Aetrix Electronics and suitable for automotive power modules, industrial SMPS designs, and telecom DC interfaces requiring stable component supply with AEC-Q101 assurance and lead-free compliance.

Supply support for SMAJ7.0H 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 power MOSFETs for automotive and industrial markets.

The SMAJ series is engineered specifically for high-reliability transient suppression in harsh environments, with emphasis on AEC-Q101 qualification, ISO 7637-2 compliance, and surface-mount manufacturability.

FAQ

What is the clamping voltage of the SMAJ7.0H under maximum rated surge conditions?

The SMAJ7.0H exhibits a maximum clamping voltage (V_C) of 13.3 V when subjected to its rated 200 A peak pulse current (I_PPM) under the standard 10/1000 µs waveform. This value is measured per JEDEC standards and guarantees predictable overvoltage limiting for protected circuits. The SMAJ7.0H maintains this clamping performance across its full operating temperature range (–55 °C to +150 °C), ensuring consistent protection in demanding environments.

Is the SMAJ7.0H suitable for bidirectional transient suppression?

No-the SMAJ7.0H is a unidirectional TVS diode, intended for use with defined polarity (anode to line, cathode to ground). For bidirectional applications, Taiwan Semiconductor specifies parts with "CH" or "CAH" suffixes (e.g., SMAJ7.0CH). Using SMAJ7.0H in reverse-biased configurations may result in unintended conduction or failure. Always verify polarity alignment in schematic and layout for the SMAJ7.0H.

Does the SMAJ7.0H meet automotive qualification standards?

Yes-the SMAJ7.0H is explicitly AEC-Q101 qualified, confirming its reliability for automotive electronic systems. It also meets ISO 7637-2 test requirements for Pulse 1, 2a, 2b, 3a, and 3b, covering load dump, supply interruption, and switching transients. These qualifications are documented in Taiwan Semiconductor's official A2102 datasheet revision and apply directly to the SMAJ7.0H part number.

What is the maximum steady-state power dissipation for the SMAJ7.0H?

The SMAJ7.0H has a maximum steady-state power dissipation (P_D) of 1 W at 25 °C ambient temperature, derating linearly above that point per the pulse derating curve in Figure 2 of the datasheet. This rating applies to continuous DC or low-frequency AC stress-not transient events. For sustained overvoltage conditions exceeding V_WM, thermal design must ensure junction temperature remains ≤150 °C, as the SMAJ7.0H is not intended for continuous regulation.

How does the SMAJ7.0H compare to the SMAJ7.0AH variant?

The SMAJ7.0AH has a tighter breakdown voltage range (7.78–8.60 V vs. 7.78–9.51 V for SMAJ7.0H) and lower clamping voltage (12.0 V vs. 13.3 V), resulting in more precise and aggressive transient suppression. Both share identical package (DO-214AC), AEC-Q101 qualification, and 400 W peak pulse rating. The SMAJ7.0H provides broader tolerance for manufacturing variation and higher surge margin, while SMAJ7.0AH suits designs requiring stricter voltage control.