Diodes Incorporated SMAJ90A-13-F

Overview

SMAJ90A-13-F from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power lines and signal interfaces. It features a 90V reverse standoff voltage (VRWM), 100–111V breakdown range (VBR), 146V maximum clamping voltage (VC) at 2.7A peak pulse current (IPP), and operates across –55°C to +150°C. Used in automotive body control modules to protect CAN transceiver power rails from load dump and ISO 7637-2 pulses.

For engineers reviewing the SMAJ90A-13-F datasheet, SMAJ90A-13-F pinout, SMAJ90A-13-F application, or SMAJ90A-13-F equivalent, key selection criteria include clamping voltage margin relative to protected IC VCC, peak pulse current capability under 8.3ms surge waveforms, unidirectional polarity alignment with DC supply rail orientation, and SMA package thermal performance under sustained ambient temperatures up to +125°C.

Technical Context

This TVS diode employs glass-passivated silicon junction construction to achieve fast response time (<1.0 ns) and stable clamping behavior during transient events. Its unidirectional configuration provides low-leakage forward conduction path while blocking reverse current until breakdown threshold is exceeded.

The device complies with IEC 61000-4-2 (ESD) and IEC 61000-4-4 (EFT) immunity standards when integrated with appropriate PCB layout-minimum trace inductance, direct grounding of cathode to chassis ground plane, and placement within 2 cm of protected IC pins.

Key Specifications

Pinout & Package

Package: SMA (DO-214AC), molded plastic case with UL 94V-0 flammability rating, cathode band marking on top surface, 0.064 g typical weight.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ90CA-13-F, this unidirectional variant delivers 5× lower IR at VRWM and avoids unnecessary capacitance doubling in DC applications; versus SMCJ90A-13-F, it trades surge capacity for 45% smaller footprint and better thermal cycling reliability in high-density assemblies.

Availability

SMAJ90A-13-F is available at Aetrix Electronics and suitable for automotive body electronics, industrial programmable logic controllers, telecom power inputs, and medical battery interface circuits requiring stable component supply and full traceability.

Supply support for SMAJ90A-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 North America.

The SMAJ series belongs to Diodes' transient voltage suppression portfolio, engineered specifically for cost-sensitive, high-volume board-level protection in automotive, industrial, and communications equipment where reliability under harsh electrical environments is critical.

FAQ

What is the maximum clamping voltage of SMAJ90A-13-F at its rated peak pulse current?

The maximum clamping voltage (VC) is 146 V when subjected to a 2.7 A peak pulse current (IPP), measured using the standardized 8.3 ms × 10 ms double-exponential waveform per IEC 61000-4-5. This value represents the upper bound of voltage imposed on protected circuitry during worst-case surge conditions and must be compared against the absolute maximum ratings of downstream components.

Is SMAJ90A-13-F suitable for AEC-Q101 qualified automotive designs?

No - SMAJ90A-13-F is the standard commercial-grade variant. For automotive applications requiring AEC-Q101 qualification, the pin-compatible SMAJ90AQ-13-F must be used; it undergoes additional stress testing including temperature cycling, high-temperature operating life, and ESD qualification per AEC requirements.

How does the SMA package affect thermal performance in continuous power dissipation?

At TL = +75°C, the SMA package supports 1.0 W steady-state power dissipation (PM(AV)). Its thermal resistance from junction-to-lead (RθJL) is approximately 30°C/W, meaning a 1W dissipation raises junction temperature by ~30°C above lead temperature. For reliable long-term operation, PCB copper area and solder joint quality must minimize thermal impedance to ambient.

Can SMAJ90A-13-F be used to protect bidirectional data lines like RS-485?

No - SMAJ90A-13-F is unidirectional and will conduct continuously if reverse-biased beyond VRWM, potentially disrupting signal integrity. For RS-485 or other AC-coupled interfaces, the bidirectional SMAJ90CA-13-F must be selected to provide symmetrical clamping for both polarities without DC path formation.