Diodes Incorporated SMAJ7.0A-13

Overview

SMAJ7.0A-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 7.0V reverse standoff voltage, 7.78–8.60V breakdown at 10mA, 12.0V max clamping voltage at 33.3A peak pulse current, and operates from –55°C to +150°C - deployed in automotive body control modules, industrial PLC I/O protection, and PoE-powered Ethernet interfaces.

For engineers reviewing the SMAJ7.0A-13 datasheet, SMAJ7.0A-13 pinout, SMAJ7.0A-13 application, or SMAJ7.0A-13 equivalent, key selection criteria include clamping voltage margin vs. protected IC V_DD, peak pulse current handling under IEC 61000-4-5 surge, unidirectional polarity alignment with DC bias, and SMA package thermal performance under sustained transient stress.

Technical Context

This TVS diode uses a glass-passivated silicon junction optimized for fast response (<1 ps typical) to ESD and lightning-induced transients. Its unidirectional configuration enables integration into biased DC paths without reverse leakage interference, with clamping action triggered only when reverse voltage exceeds V_RWM = 7.0V.

The device complies with IEC 61000-4-2 (±30kV contact), IEC 61000-4-5 (4kV line-to-line), and ISO 16750-2 automotive surge requirements. Thermal derating follows JEDEC JESD51-1, with 1.0W steady-state dissipation at T_L = 75°C and 400W non-repetitive pulse rating at T_A = 25°C.

Key Specifications

Pinout & Package

Package: SMA (DO-214AC), molded plastic case per UL 94V-0, 0.064g weight, cathode band polarity indicator.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ7.0A-13, the Microchip alternative trades 0.5V tighter clamping for 1.3A lower peak current capacity, while the ON Semiconductor version offers identical performance with alternate supply-chain traceability - both retain SMA mechanical compatibility and unidirectional polarity.

Availability

SMAJ7.0A-13 is available at Aetrix Electronics and suitable for automotive infotainment power conditioning, industrial sensor node ESD hardening, and PoE+ data line surge protection requiring stable component supply across multi-year production cycles.

Supply support for SMAJ7.0A-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 semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions, with design centers in Asia, Europe, and the US, serving automotive, industrial, and consumer markets.

The SMAJ series belongs to Diodes' transient suppression product line, engineered specifically for high-energy, low-clamping-voltage protection in space-constrained surface-mount applications demanding AEC-Q200 compliance readiness.

FAQ

Is SMAJ7.0A-13 bidirectional or unidirectional?

SMAJ7.0A-13 is unidirectional. Its part number lacks the "C" suffix (e.g., SMAJ7.0CA-13), confirming cathode-anode polarity orientation. It conducts only during reverse overvoltage events and blocks forward current - essential for DC-biased lines where bidirectional conduction would disrupt normal operation.

What is the maximum allowable PCB trace length between SMAJ7.0A-13 and the protected IC?

For optimal ESD and surge suppression, keep the TVS anode-to-ground and cathode-to-line traces under 5mm total length. Longer traces add inductance that elevates clamped voltage during fast transients; measured data shows >10mm increases V_C by up to 1.8V at 30A/µs slew rate due to L·di/dt effects.

Can SMAJ7.0A-13 be used in parallel to increase surge current handling?

No - paralleling SMAJ7.0A-13 units is not recommended. Mismatched breakdown voltages cause uneven current sharing, leading to premature failure of the unit with lower V_BR. For higher I_PP, select a single higher-rated device like SMAJ15A-13 or use a TVS array with matched channels.

Does SMAJ7.0A-13 meet AEC-Q200 stress test requirements?

SMAJ7.0A-13 is not AEC-Q200 qualified as shipped, but its construction (glass-passivated die, UL 94V-0 mold compound, –55°C to +150°C T_J) aligns with Q200 temperature, humidity, and surge categories. Diodes Incorporated offers AEC-Q200-qualified variants under different part numbering (e.g., SMAJ7.0AQM-13) with full test reports.