Diodes Incorporated SMF4L8.0A-7

Overview

SMF4L8.0A-7 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) designed for overvoltage clamping in low-voltage DC power rails. It features a 8.0V working peak reverse voltage (VRWM), 8.89V minimum breakdown voltage (VBR), 13.6V maximum clamping voltage (VC) at 29.4A peak pulse current, and <50µA reverse leakage at VRWM - optimized for protecting USB ports, battery management circuits, and automotive body electronics.

For engineers reviewing the SMF4L8.0A-7 datasheet, SMF4L8.0A-7 pinout, SMF4L8.0A-7 application, or SMF4L8.0A-7 equivalent, key selection criteria include clamping performance under IEC 61000-4-2 ±30kV ESD stress, DO-219AA package thermal resistance (RθJA = 96°C/W), unidirectional polarity marking, and compatibility with automated SMT assembly on FR-4 PCBs with 2 oz. copper pads.

Technical Context

This TVS diode operates as a voltage-clamped shunt protector: when transient voltage exceeds its breakdown threshold (8.89–9.83V), it avalanches to divert surge current away from downstream ICs. Its fast response (<1.0ns from 0V to VBR) ensures protection against nanosecond-scale ESD events before sensitive circuitry is damaged.

The device uses a planar junction structure in a molded DO-219AA package with matte tin-plated copper alloy leads, enabling low-inductance operation and stable clamping across -55°C to +175°C ambient range. Thermal design relies on PCB copper area for heat dissipation, with RθJS = 70°C/W to soldering point.

Key Specifications

Pinout & Package

DO-219AA is a two-terminal surface-mount package with cathode band indicating the cathode terminal. The device has no internal pins; terminals are formed by the anode and cathode metallized ends of the silicon die, exposed via the molded plastic body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ8.0A and TPSMA6.8A, SMF4L8.0A-7 delivers identical clamping performance in a 45% smaller footprint (DO-219AA), enabling higher board density and improved high-frequency transient response due to lower parasitic inductance - critical for USB and automotive signal integrity.

Availability

SMF4L8.0A-7 is available at Aetrix Electronics and suitable for USB interface protection, automotive body electronics, Li-ion battery terminal safeguarding, and industrial sensor signal conditioning requiring stable component supply across production lifecycles.

Supply support for SMF4L8.0A-7 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, specializing in high-reliability protection, power management, and signal integrity solutions for industrial, automotive, and consumer markets.

The SMF4L series belongs to Diodes' high-power surface-mount TVS portfolio, engineered specifically for space-constrained applications demanding robust IEC 61000-4-2 ESD immunity and low-clamping-voltage protection of low-voltage DC rails.

FAQ

What is the polarity configuration of SMF4L8.0A-7?

SMF4L8.0A-7 is a unidirectional TVS diode, identified by a visible cathode band on the DO-219AA package. It conducts only when the cathode is biased positively relative to the anode, making it suitable for DC rail protection where reverse voltage is not expected. Bidirectional variants (e.g., SMF4L8.0CA-7) omit the band and clamp both polarities.

Can SMF4L8.0A-7 be used in automotive applications?

Yes - SMF4L8.0A-7 is manufactured in IATF 16949-certified facilities and supports automotive qualification pathways. While the standard part is not AEC-Q101 certified, Diodes offers Q-suffix automotive-grade versions (e.g., SMF4L8.0AQ-7) with full PPAP documentation, extended temperature validation (-40°C to +125°C case), and enhanced reliability testing for BCM, infotainment, and ADAS subsystems.

How does the DO-219AA package affect thermal performance?

The DO-219AA package achieves RθJA = 96°C/W on a 1"×1" FR-4 board with 2 oz. copper, significantly better than legacy SMA packages. Its low-profile geometry (max height 0.75mm) and direct die-to-pad thermal path reduce junction-to-board resistance (RθJS = 70°C/W), allowing reliable operation at +175°C junction temperature - essential for under-hood automotive environments.

What is the maximum surge current SMF4L8.0A-7 can handle without degradation?

SMF4L8.0A-7 is rated for 29.4A peak pulse current (IPP) under the standardized 10/1000µs waveform. It withstands this current without parametric shift or failure when mounted per datasheet layout (1"×1" FR-4, 2 oz. Cu). Repeated surges above 80% of IPP require derating per Figure 1; single-event capability remains intact up to the full 29.4A rating.