Taiwan Semiconductor Corporation SMAJ58CA

Overview

SMAJ58CA from Taiwan Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for robust overvoltage protection in DC power rails. It features a 58 V working stand-off voltage (V_WM), 64.4–71.2 V breakdown voltage (V_BR), and clamps transients to ≤93.6 V at 4.3 A peak impulse current, meeting ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive electronics.

For engineers reviewing the SMAJ58CA datasheet, SMAJ58CA pinout, SMAJ58CA application, or SMAJ58CA equivalent, key selection criteria include bidirectional clamping capability, 400 W peak pulse power (10/1000 µs), low leakage (<1 µA @ 58 V), fast response (<1.0 ps), and compliance with J-STD-020 Level 1 moisture sensitivity and RoHS/halogen-free requirements.

Technical Context

The SMAJ58CA operates as a silicon avalanche diode with glass-passivated junction, enabling precise, repeatable breakdown behavior under transient stress. Its bidirectional configuration supports symmetric clamping in AC-coupled or floating bus applications without polarity constraints.

It delivers 400 W peak pulse power per 10/1000 µs waveform up to 78 V - above which rating reduces to 300 W - and maintains stable clamping performance across -55 °C to +150 °C junction temperature range, validated per JEDEC JESD201 Class 2 whisker testing and UL 94V-0 molding compound.

Key Specifications

Pinout & Package

DO-214AC (SMA) surface-mount package: molded epoxy case with matte tin-plated leads, 0.060 g weight, polarity indicated by cathode band (bidirectional operation eliminates functional polarity dependence).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ58CA and P6SMB58CA, the SMAJ58CA offers identical clamping performance in a smaller DO-214AC footprint - reducing board area by ~30% and enabling tighter placement near connectors - while maintaining full automotive-grade surge immunity and automated assembly compatibility.

Availability

SMAJ58CA is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial switch-mode power supplies, and LED lighting applications requiring stable component supply, consistent parametric performance, and full traceability across production batches.

Supply support for SMAJ58CA 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 management components since 1979.

The SMAJ series was developed specifically for surface-mount transient protection in automotive and industrial power systems, emphasizing high reliability, tight parameter distribution, and compliance with stringent environmental and safety standards including AEC-Q101 stress testing.

FAQ

What is the clamping voltage of SMAJ58CA at its rated peak pulse current?

The SMAJ58CA clamps to a maximum of 93.6 V when subjected to its rated peak impulse current of 4.3 A under the standardized 10/1000 µs waveform. This value is measured per the manufacturer's test conditions and defines the upper voltage limit imposed on protected circuitry during surge events. The SMAJ58CA achieves this clamping performance while maintaining bidirectional symmetry and sub-1 µA leakage at 58 V.

Is SMAJ58CA suitable for automotive applications requiring ISO 7637-2 compliance?

Yes, the SMAJ58CA is explicitly rated to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b test requirements, making it suitable for protecting 12 V and 24 V automotive subsystems such as infotainment, body control modules, and lighting drivers. Its 400 W peak pulse power rating, fast <1.0 ps response, and -55 °C to +150 °C operating range align with AEC-Q101-recommended stress profiles. The SMAJ58CA also complies with J-STD-020 Level 1 moisture sensitivity for robust reflow processing.

What does the "CA" suffix indicate in SMAJ58CA?

The "CA" suffix in SMAJ58CA denotes a bidirectional configuration - meaning the device provides symmetrical transient suppression in both forward and reverse directions, with identical V_BR, V_C, and I_PPM characteristics regardless of voltage polarity. This eliminates the need for polarity-aware placement on PCBs and supports use in AC-coupled lines or floating buses. In contrast, "A"-suffix unidirectional variants (e.g., SMAJ58A) have an anode/cathode orientation and asymmetric forward conduction behavior.

What is the maximum steady-state power dissipation of SMAJ58CA?

The SMAJ58CA has a maximum steady-state power dissipation (P_D) of 1 W at 25 °C ambient temperature, as specified in its Absolute Maximum Ratings table. This rating applies to continuous DC or low-frequency reverse-biased operation and must be thermally derated linearly above 25 °C per the manufacturer's pulse derating curve. The SMAJ58CA is not intended for sustained power dissipation; its design focus is transient energy absorption, where it handles up to 400 W in short-duration (10/1000 µs) pulses.

Does SMAJ58CA require special handling or baking prior to reflow soldering?

No, the SMAJ58CA is rated at J-STD-020 Moisture Sensitivity Level 1, meaning it may be stored indefinitely at ≤30 °C/60% RH and processed using standard Pb-free or SnPb reflow profiles without pre-baking. Its DO-214AC (SMA) package uses UL 94V-0 compliant molding compound and matte tin-plated leads that meet J-STD-002 solderability requirements. This eliminates moisture-related popcorning risk and supports high-throughput automated placement - a key advantage of the SMAJ58CA in volume manufacturing environments.