Diodes Incorporated SMAJ8.0A-13

Overview

SMAJ8.0A-13 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power rails and signal lines. It features a 8.0V reverse standoff voltage (VRWM), 8.89–9.83V breakdown voltage (VBR) at 1mA, 13.6V max clamping voltage (VC) at 29.4A peak pulse current (IPP), and operates from –55°C to +150°C.

For engineers reviewing the SMAJ8.0A-13 datasheet, SMAJ8.0A-13 pinout, SMAJ8.0A-13 application, or SMAJ8.0A-13 equivalent, key selection criteria include clamping performance under 8.3ms surge, unidirectional polarity handling, SMA package thermal dissipation limits, and compatibility with IPC-7351B footprint standards for automated assembly.

Technical Context

This TVS diode uses glass-passivated silicon junction construction to achieve fast response time (<1ps) and stable clamping during ESD and lightning-induced transients. Its unidirectional configuration provides low-leakage forward blocking while enabling robust reverse-biased surge suppression up to 400W peak pulse power.

The device complies with IEC 61000-4-2 (ESD) and IEC 61000-4-5 (surge) immunity requirements when properly laid out with minimal trace inductance. Thermal derating follows JEDEC-defined curves, maintaining 100% rated power only at TA ≤ 25°C and dropping to ~50% at TA = 75°C.

Key Specifications

Pinout & Package

Package: SMA (DO-214AC), molded plastic case with UL 94V-0 flammability rating, cathode band polarity indicator, and 0.064g typical weight. Terminals are solderable per MIL-STD-202, Method 208.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ8.0A-13, SMAJ8.0CA-13 supports bidirectional transients but sacrifices unidirectional leakage performance, while SMBJ8.0A-13 trades compactness for improved thermal headroom-making SMAJ8.0A-13 optimal for space-constrained 24V industrial I/O designs requiring minimal standby loss.

Availability

SMAJ8.0A-13 is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive body control modules, and consumer power adapter output stages requiring stable component supply across multi-year production cycles.

Supply support for SMAJ8.0A-13 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 and manufacturing operations across Asia and the Americas.

SMAJ series TVS diodes are part of Diodes' circuit protection product line, engineered specifically for high-reliability DC rail and interface line protection in automotive, industrial, and computing applications.

FAQ

What is the maximum clamping voltage for SMAJ8.0A-13 under standard test conditions?

The maximum clamping voltage (VC) is 13.6 V when subjected to a 29.4 A peak pulse current (IPP) using the 8.3 ms single half-sine waveform defined in IEC 61000-4-5. This value is measured at TJ = 25°C with terminals held at ambient temperature, and remains valid within the specified derating curve up to TA = 75°C.

Can SMAJ8.0A-13 be used in bidirectional signal lines like RS-485?

No - SMAJ8.0A-13 is unidirectional and will conduct continuously if reverse-biased beyond VRWM, making it unsuitable for AC or floating differential lines. For RS-485, use the bi-directional variant SMAJ8.0CA-13, which clamps equally in both directions with symmetrical VBR and VC characteristics.

How does the SMA package affect thermal performance in high-density PCB layouts?

The SMA (DO-214AC) package has a thermal resistance of approximately 100°C/W junction-to-ambient (RθJA) in standard FR-4 layout. With 1.0 W steady-state power dissipation limit at TL = 75°C, designers must ensure ≥25 mm² of 1-oz copper pour connected to both terminals and avoid placement near heat sources to maintain safe junction temperatures.

Is SMAJ8.0A-13 compliant with RoHS and lead-free assembly processes?

Yes - SMAJ8.0A-13 is supplied with matte tin plating and meets RoHS Directive 2011/65/EU, including exemptions for high-temperature soldering (Annex III Notes 5 and 7). It is compatible with standard Pb-free reflow profiles up to 260°C peak, and moisture sensitivity level is rated at MSL 1 per J-STD-020C.