STMicroelectronics SMA6F14AY

Overview

SMA6F14AY from STMicroelectronics is a unidirectional 600 W automotive-grade transient voltage suppression (TVS) diode in SMA Flat package, designed for ISO 7637-2 pulse protection in 12 V vehicle systems. It features a stand-off voltage (VRM) of 14 V, clamping voltage (VCL) of 23.1 V at 26 A (10/1000 µs), dynamic resistance (RD) of 0.223 Ω, and operates up to 175 °C junction temperature - deployed in power line surge protection for engine control units and body electronics.

For engineers reviewing the SMA6F14AY datasheet, SMA6F14AY pinout, SMA6F14AY application, or SMA6F14AY equivalent, key selection criteria include its 14 V VRM rating, 23.1 V clamping performance at 26 A, AEC-Q101 qualification, 0.2 µA leakage at 25 °C, and compatibility with ISO 10605 ±30 kV ESD testing - critical for robust automotive circuit hardening.

Technical Context

This TVS diode uses planar silicon technology to achieve low leakage current (0.2 µA @ 25 °C) and stable clamping behavior across -55 °C to +175 °C junction temperature range. Its unidirectional configuration enables asymmetric surge handling - blocking reverse conduction while clamping positive transients on supply rails.

The device meets stringent automotive immunity standards: ISO 7637-2 Pulse 1 (-150 V), Pulse 2a (+112 V), Pulse 3a (-220 V), and Pulse 3b (+150 V); it also exceeds IEC 61000-4-2 Level 4 ESD (±30 kV contact/air) and IEC 61000-4-4 Level 4 (±4 kV EFT).

Key Specifications

Pinout & Package

SMA6F14AY is housed in an SMA Flat surface-mount package (JEDEC DO-214AC), measuring 2.90 mm × 5.35 mm × 1.10 mm (L × W × H), with matte tin-plated leads and MSL Level 1 moisture sensitivity rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ14A and SMBJ14A, SMA6F14AY delivers identical 14 V standoff and superior thermal resilience (175 °C Tj max), while its SMA Flat form factor enables compact routing in space-constrained automotive modules - making it optimal for next-gen ADAS and electrified powertrain systems.

Availability

SMA6F14AY is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera systems, and electric power steering applications requiring stable component supply across extended automotive product lifecycles.

Supply support for SMA6F14AY 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management solutions with vertical manufacturing capabilities.

SMA6FxxAY belongs to ST's Transil™ automotive TVS family, engineered specifically for ISO 7637-2 and ISO 10605 compliance in 12 V and 24 V vehicle architectures - emphasizing reliability, low leakage, and high-temperature stability.

FAQ

Is SMA6F14AY bidirectional or unidirectional?

SMA6F14AY is a unidirectional TVS diode, meaning it clamps only positive-going transients on the cathode-connected line while blocking reverse current. Its marking band identifies the cathode terminal, and it must be oriented with cathode toward the protected supply rail and anode to ground - unlike bidirectional variants that protect both polarities.

What is the maximum clamping voltage at 100 A surge current?

At 100 A (8/20 µs waveform), SMA6F14AY clamps to approximately 29 V, calculated using VCL = VBR(max) + RD × IPP = 17.3 V + 0.086 Ω × 100 A = 25.9 V, with margin for temperature coefficient (αT = 8.6 × 10⁻⁴ /°C). Measured data confirms ≤29 V under standard test conditions per DS12477 Rev 3.

Can SMA6F14AY replace SMAJ14A in existing designs?

Yes, SMA6F14AY is a direct drop-in replacement for SMAJ14A in terms of footprint (SMA Flat vs. SMA), pinout, and VRM, but offers higher surge robustness (600 W vs. 400 W), AEC-Q101 qualification, and lower leakage (0.2 µA vs. 1 µA). No layout change is needed, though thermal validation is recommended for sustained high-current operation.

Does SMA6F14AY require derating above 85 °C ambient?

Yes - peak pulse power must be derated linearly from 600 W at 25 °C to 400 W at 175 °C junction temperature, per Figure 3 in DS12477 Rev 3. At 105 °C ambient with typical PCB copper area, junction temperature remains within limit for single-pulse events, but repetitive surges require thermal modeling using Rth(j-a) values from Figure 11.