STMicroelectronics SMA4F16A

Overview

SMA4F16A from STMicroelectronics is a unidirectional 400 W transient voltage suppression (TVS) diode designed for primary-level surge protection in DC power rails and signal lines. It features a 16 V stand-off voltage (VRM), 17.9–19.8 V breakdown voltage (VBR) at 1 mA, 26 V clamping voltage (VCL) at 15.4 A (10/1000 µs), and operates up to 175 °C junction temperature - deployed in industrial power supplies and automotive body control modules.

For engineers reviewing the SMA4F16A datasheet, SMA4F16A pinout, SMA4F16A application, or SMA4F16A equivalent, key selection criteria include clamping performance under IEC 61000-4-2 Level 4 (±25 kV contact / ±30 kV air), low leakage (0.2 µA @ 25 °C), dynamic resistance of 0.403 Ω, and compatibility with standard SMA flat package reflow profiles per J-STD-020 MSL Level 1.

Technical Context

The SMA4F16A uses planar silicon avalanche technology to deliver precise, repeatable clamping with minimal capacitance and leakage. Its unidirectional configuration enables integration on positive-rail-only paths without reverse-bias concerns, and its thermal design supports sustained operation at Tj = 175 °C with derated pulse power up to 200 W.

Electrical behavior is defined by three core parameters: VBR (17.9–19.8 V), VCL (26 V @ 15.4 A, 10/1000 µs), and RD (0.403 Ω), enabling accurate overvoltage margining in 24 V systems. Temperature coefficients (αT = 9.0 × 10⁻⁴ /°C) allow predictable VBR/VCL drift across –55 °C to +175 °C operating range.

Key Specifications

Pinout & Package

Package: SMA Flat (DO-214AC), surface-mount, matte tin-plated leads, JEDEC registered outline, IPC7531 footprint compliant. Dimensions: D = 2.25–2.90 mm, E = 5.00–5.35 mm, E1 = 3.95–4.60 mm, A = 0.90–1.10 mm, b = 1.25–1.65 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ16A and SMBJ16A, SMA4F16A offers tighter VCL (26 V vs. 27.7 V/26.9 V) and superior high-temperature stability (175 °C Tj max vs. 150 °C), making it optimal for compact, thermally constrained 24 V industrial designs requiring guaranteed clamping margin.

Availability

SMA4F16A is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, smart energy meter power supplies, and outdoor PoE switch ports requiring stable component supply across extended temperature and surge stress conditions.

Supply support for SMA4F16A 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 power management, analog, MEMS, and microcontrollers for industrial, automotive, and consumer markets.

The SMA4F Transil series targets high-reliability transient protection in thermally demanding environments, leveraging planar silicon technology to achieve low leakage, high Tj operation, and precise clamping - optimized for 24 V and 48 V DC systems in harsh settings.

FAQ

What is the maximum clamping voltage of SMA4F16A under IEC 61000-4-2 ESD stress?

The SMA4F16A does not specify clamping voltage under IEC 61000-4-2 ESD waveforms (150 pF/330 Ω); its 26 V VCL rating applies to 10/1000 µs surges. Under 8/20 µs pulses, VCL is 34.7 V at 67 A. For ESD, its robustness is validated at ±25 kV contact/±30 kV air, but clamping behavior is waveform-dependent and not characterized as a fixed voltage.

Can SMA4F16A be used in bidirectional signal line protection?

No - SMA4F16A is unidirectional and only protects against positive-going transients on the cathode side. For bidirectional protection (e.g., RS-485, USB), two devices must be connected in series opposition, or a dedicated bidirectional TVS like SMA4F16AY should be selected instead.

What is the thermal resistance (Rth j-a) of SMA4F16A on a standard FR4 PCB?

On a recommended footprint (FR4, 35 µm Cu, 2 cm² copper area per lead), Rth(j-a) is approximately 120 °C/W for single-pulse conditions. With 4.5 cm² total copper area, it drops to ~45 °C/W - enabling sustained 175 °C operation under pulsed loads when layout guidelines are followed.

Does SMA4F16A meet AEC-Q101 qualification for automotive use?

Yes - the SMA4F series is qualified per AEC-Q101 Rev E for stress testing including HTGB, HTRB, TCT, and ESD. The SMA4F16A specifically passes temperature cycling (–55 °C to +175 °C), high-temperature reverse bias, and mechanical shock tests required for under-hood and body electronics applications.