Diodes Incorporated SMAJ58CA-13-F

Overview

SMAJ58CA-13-F from Diodes Incorporated is a bidirectional 400W transient voltage suppressor (TVS) diode in SMA package, designed for overvoltage protection of DC power lines and signal interfaces. It features a 58V reverse standoff voltage (VRWM), 64.4–71.2V breakdown range (VBR), 93.6V max clamping voltage (VC) at 4.3A peak pulse current (IPP), and operates from –55°C to +150°C - used in automotive infotainment power rail protection.

For engineers reviewing the SMAJ58CA-13-F datasheet, SMAJ58CA-13-F pinout, SMAJ58CA-13-F application, or SMAJ58CA-13-F equivalent, key selection criteria include clamping voltage margin vs. protected IC VCC tolerance, unidirectional/bidirectional polarity match with circuit topology, IEC 61000-4-2/4-5 surge compliance, and thermal derating above +25°C ambient.

Technical Context

This bidirectional TVS operates symmetrically across both polarities, enabling protection of AC-coupled or floating signal paths without polarity constraints. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<5 µA at VRWM), while fast response time (<1 ns) limits voltage overshoot during ESD or lightning-induced transients.

The device complies with IEC 61000-4-2 (±30 kV contact discharge) and IEC 61000-4-5 (4 kV 8/20 µs surge) when properly laid out with low-inductance PCB routing. Its 400W peak pulse power rating is valid for non-repetitive 10/1000 µs waveform pulses at ≤4 pulses/minute, with linear derating above +25°C ambient per Fig. 1.

Key Specifications

Pinout & Package

SMAJ58CA-13-F uses the SMA (DO-214AC) package: molded plastic case, UL 94V-0 rated, cathode band omitted (bidirectional), matte tin-plated terminals, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ58CA-13-F, the unidirectional SMAJ58A-13-F reduces design flexibility in floating or AC-coupled systems, while SMBJ58CA-13-F trades board space for higher surge endurance - making SMAJ58CA-13-F optimal for space-constrained bidirectional protection where 400W suffices.

Availability

SMAJ58CA-13-F is available at Aetrix Electronics and suitable for automotive infotainment power rail protection, industrial RS-485 interface hardening, and consumer USB-C port ESD suppression requiring stable component supply across production ramps.

Supply support for SMAJ58CA-13-F 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.

This device belongs to Diodes' SMAJ series of surface-mount TVS diodes, engineered specifically for high-reliability transient suppression in automotive, industrial, and communications equipment where compact size and bidirectional symmetry are critical.

FAQ

What does the 'C' suffix in SMAJ58CA-13-F indicate?

The 'C' denotes bidirectional configuration: both terminals behave identically under positive or negative transients, eliminating polarity dependency. This differs from unidirectional variants (e.g., SMAJ58A-13-F) that conduct only when cathode is more positive than anode. The marking code 'RG' on the device body confirms this variant per Diodes' datasheet Table 1.

Can SMAJ58CA-13-F be used in place of a unidirectional TVS?

Yes, but only if the protected circuit is inherently symmetrical or floating - such as RS-485 differential pairs or AC signal lines. In unidirectional DC rails (e.g., 12V to GND), using a bidirectional device introduces unnecessary conduction risk during normal operation if voltage reversals occur, unlike unidirectional types that block forward current.

What is the maximum recommended PCB trace inductance for effective ESD protection?

For sub-1 ns response time to be effective, total loop inductance (including trace + via + device) should be ≤5 nH. Achieve this with short, wide traces (≤5 mm length, ≥0.5 mm width), direct grounding to solid plane, and placement within 3 mm of the protected connector - verified by TDR measurement or EM simulation per IEC 61000-4-2 layout guidelines.

How does temperature affect clamping voltage performance?

VBR and VC increase with junction temperature at ~0.1%/°C; at +125°C, VC rises ~10 V above room-temperature value. Derating curves (Fig. 1) show 400W rating drops to ~260W at +85°C ambient. Designers must verify worst-case clamping remains below protected IC's absolute maximum rating using thermal modeling and ambient+power dissipation estimates.