STMicroelectronics SMA6F170A

Overview

SMA6F170A from STMicroelectronics is a unidirectional 600 W transient voltage suppression (TVS) diode designed for high-reliability surge protection in DC power rails and signal lines. It features a 170 V stand-off voltage (VRM), 275 V maximum clamping voltage at 1 A (10/1000 µs), 2.2 Ω dynamic resistance, and operates up to 175 °C junction temperature - deployed in industrial power supplies and telecom interface protection.

For engineers reviewing the SMA6F170A datasheet, SMA6F170A pinout, SMA6F170A application, or SMA6F170A equivalent, key selection criteria include clamping performance under 10/1000 µs surges, low leakage (<1 µA at 85 °C), thermal stability at Tj = 175 °C, and compliance with IEC 61000-4-2 Level 4 (±25 kV contact / ±30 kV air discharge).

Technical Context

The SMA6F170A uses planar silicon avalanche technology to deliver precise breakdown at 190–210 V (VBR min/max @ 1 mA), with clamping governed by dynamic resistance (RD = 2.2 Ω) and temperature coefficient αT = 10.8 × 10⁻⁴ /°C. Its unidirectional architecture enables asymmetric surge handling on positive-polarity lines only.

Thermal design is enabled by its SMA flat package's low thermal impedance (Zth(j-a) ≈ 100 °C/W for single pulse on FR4), supporting sustained operation at Tj = 175 °C while maintaining <0.2 µA leakage at 25 °C and <1 µA at 85 °C - critical for long-life industrial deployments.

Key Specifications

Pinout & Package

The SMA6F170A is housed in an industry-standard SMA (DO-214AC) flat plastic package with matte tin-plated leads, compliant with IPC7531 footprint and JEDEC MO-136AA outline. Dimensions: D = 2.25–2.90 mm, E = 5.00–5.35 mm, E1 = 3.95–4.60 mm, L = 0.75–1.20 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ170A and 1.5SMC170A, the SMA6F170A delivers superior thermal resilience (175 °C vs. ≤150 °C), tighter clamping (275 V vs. ≥285 V), and lower dynamic resistance (2.2 Ω vs. ≥2.5 Ω), making it optimal for high-reliability, thermally constrained industrial and automotive applications.

Availability

SMA6F170A is available at Aetrix Electronics and suitable for industrial power supply input protection, telecom line interface protection, automotive body control module (BCM) power rail protection, and smart meter auxiliary supply protection requiring stable component supply across extended temperature and surge stress conditions.

Supply support for SMA6F170A 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, delivering intelligent power, sensing, and control solutions for industrial, automotive, and consumer markets.

The SMA6F Transil series targets high-reliability transient suppression in space-constrained, thermally demanding applications - engineered for long-term stability under repeated surge stress and elevated junction temperatures.

FAQ

What is the maximum clamping voltage of SMA6F170A under a 10/1000 µs surge?

The SMA6F170A exhibits a maximum clamping voltage (VCL) of 275 V when subjected to a 1 A, 10/1000 µs surge waveform at 25 °C ambient. This value scales with junction temperature using αT = 10.8 × 10⁻⁴ /°C, reaching ~295 V at Tj = 175 °C per datasheet calculation VCL(Tj) = VCL(25 °C) × [1 + αT × (Tj − 25)].

Does SMA6F170A meet IEC 61000-4-2 ESD immunity requirements?

Yes - the SMA6F170A exceeds IEC 61000-4-2 Level 4, withstanding ±25 kV contact discharge and ±30 kV air discharge (C = 150 pF, R = 330 Ω). This is verified per the DS12564 Rev 3 datasheet and confirmed by ST's compliance documentation referencing UL94 V0 and JESD22-B102 E3 test standards.

Can SMA6F170A be used in bidirectional protection circuits?

No - the SMA6F170A is strictly unidirectional, as indicated by its "A" suffix and electrical characterization (no reverse breakdown specification). For bidirectional protection, ST offers the SMA6F170CA variant; substituting SMA6F170A in AC-coupled or symmetrical surge paths will result in forward conduction and potential failure.

What is the recommended PCB footprint for SMA6F170A?

The recommended footprint follows IPC7531 and JEDEC MO-136AA standards: pad length ≥3.0 mm, pad width ≥1.5 mm, solder mask opening matching copper, with ≥1 cm² copper pour per lead to achieve Rth(j-a) ≤ 50 °C/W. ST's DS12564 Rev 3 Figure 13 provides exact dimensions in mm and inches for FR4 boards with 35 µm Cu thickness.