Diodes Incorporated SMF4L64AQ-7

Overview

SMF4L64AQ-7 from Diodes Incorporated is a unidirectional 400W transient voltage suppressor (TVS) diode in DO-219AA package, with 64V working peak reverse voltage (VRWM), 71.1–78.6V breakdown voltage (VBR), and 103V maximum clamping voltage (VC) at 3.9A surge current. It delivers ±30kV ESD protection per IEC61000-4-2 and is AEC-Q101 qualified for automotive power rail and battery contact protection.

For engineers reviewing the SMF4L64AQ-7 datasheet, SMF4L64AQ-7 pinout, SMF4L64AQ-7 application, or SMF4L64AQ-7 equivalent, this device is selected for high-reliability DC power line surge suppression where low clamping voltage, fast response (<1.0ns), and compact surface-mount form factor are critical - especially in automotive infotainment power supplies, ADAS sensor modules, and EV battery management interfaces.

Technical Context

This TVS operates as a unidirectional clamping device, triggered when reverse voltage exceeds its 64V standoff threshold, diverting transient energy to ground before downstream circuitry sustains damage. Its silicon avalanche structure ensures sub-nanosecond response and stable clamping across temperature (-55°C to +175°C).

Designed for 10/1000µs waveform compliance, it handles up to 400W peak pulse power and 40A non-repetitive forward surge current. The DO-219AA package enables high thermal efficiency (RθJA = 96°C/W) and supports automated SMT assembly with 3000-piece tape-and-reel packaging.

Key Specifications

Pinout & Package

Package: DO-219AA - ultra-compact, flat-lead surface-mount package (2.80 mm × 1.90 mm × 0.60 mm), matte tin-plated copper alloy leadframe, RoHS-compliant and halogen-free ("Green"). Moisture sensitivity level 1 (J-STD-020).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar unidirectional TVS diode applications.

Compared with SMAJ64A and TPSMD64A, SMF4L64AQ-7 offers superior thermal performance (96°C/W vs. ≥125°C/W), smaller DO-219AA footprint, and full AEC-Q101 qualification - making it the preferred choice for new automotive designs requiring high-density, high-reliability transient suppression.

Availability

SMF4L64AQ-7 is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS camera modules, and EV battery management systems requiring stable component supply with full AEC-Q101 traceability and IATF 16949 manufacturing compliance.

Supply support for SMF4L64AQ-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 automotive, industrial, and consumer markets.

The SMF4L series belongs to Diodes' AEC-Q101-qualified TVS portfolio, engineered specifically for next-generation automotive power rail and interface protection where miniaturization, low clamping, and extended temperature operation are mandatory.

FAQ

Is SMF4L64AQ-7 bidirectional or unidirectional?

SMF4L64AQ-7 is a unidirectional TVS diode, indicated by the absence of "C" in its part number (unlike SMF4L64CAQ). It features a cathode band marking and clamps only during reverse-voltage transients - ideal for DC power line protection where polarity is fixed and forward conduction must be avoided.

What is the maximum clamping voltage at rated surge current?

The maximum clamping voltage (VC) for SMF4L64AQ-7 is 103 V at 3.9 A peak reverse surge current (IRSM), measured using the 10/1000 µs standard waveform. This value is guaranteed across the full operating temperature range (−55°C to +175°C) and defines the upper voltage limit imposed on protected circuits during transient events.

Does SMF4L64AQ-7 require derating at elevated ambient temperatures?

Yes - its peak pulse power rating decreases linearly above +25°C ambient, per Figure 1 in DS43393 Rev. 3-2. At +125°C, the device retains approximately 65% of its 400W rating (≈260W), due to junction temperature limitations. Designers must apply this derating curve when sizing for under-hood or high-power-density applications.

Can SMF4L64AQ-7 replace SMAJ64A in existing layouts?

No - SMF4L64AQ-7 uses the DO-219AA package (2.80 mm × 1.90 mm), while SMAJ64A uses DO-214AC (4.5 mm × 2.7 mm). The footprint, pad dimensions, and thermal pad requirements differ significantly. Direct replacement requires PCB redesign; however, electrical performance (VRWM, VC, PPK) is functionally equivalent.