STMicroelectronics SM2T14A

Overview

SM2T14A from STMicroelectronics is a unidirectional Transil™ TVS diode designed for ESD and transient overvoltage protection in portable electronics. It features a 12 V stand-off voltage (VRM), 13.3 V breakdown voltage (VBR) at 1 mA, 19.9 V clamping voltage (VCL) at 9 A peak pulse current, and 200 W peak pulse power (10/1000 µs), deployed in battery-powered handheld devices and USB interface circuits.

For engineers reviewing the SM2T14A datasheet, SM2T14A pinout, SM2T14A application, or SM2T14A equivalent, key selection criteria include clamping performance under 8/20 µs surges, low leakage (<1 µA @ 12 V), junction-to-ambient thermal resistance (250 °C/W on recommended PCB layout), and compatibility with automated SMT assembly using JEDEC DO-216AA (STmite) package.

Technical Context

The SM2T14A operates as a unidirectional avalanche clamp, triggered when reverse voltage exceeds its 13.3 V breakdown threshold. Its low clamping factor (VCL/VBR = 1.49) ensures minimal overvoltage stress on protected ICs during transients up to 9 A (10/1000 µs) or higher-energy 8/20 µs events.

Thermal design relies on its 250 °C/W junction-to-ambient resistance on FR4 PCB with specified pad layout, and its 1.0 mm profile enables ultra-thin device integration. The 650 pF junction capacitance at 0 V supports signal integrity in low-speed data lines like USB 2.0 D+/D− or I²C buses.

Key Specifications

Pinout & Package

SM2T14A uses the DO-216AA (STmite) surface-mount package: cathode-marked single-terminal device with anode and cathode leads formed into gull-wing configuration. Overall height is 1.0 mm, footprint measures 1.90 × 1.90 mm (E × D), and thermal tab is integrated into the cathode lead.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ14A and P6SMB14A, SM2T14A offers the lowest profile (1.0 mm) and tightest VBR tolerance (13.3 V typ), making it optimal for space-constrained portable designs where precise clamping voltage and minimal board thickness are critical.

Availability

SM2T14A is available at Aetrix Electronics and suitable for USB interface protection, smartphone battery line safeguarding, industrial sensor signal conditioning, and I²C bus ESD hardening requiring stable component supply across high-mix production runs.

Supply support for SM2T14A 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 discrete solutions with vertical manufacturing capabilities.

The SM2T series belongs to ST's Transil™ TVS portfolio, engineered specifically for miniaturized portable electronics requiring ultra-low-profile, high-reliability ESD and surge protection in space- and power-constrained environments.

FAQ

What is the maximum allowable mounting temperature for SM2T14A during reflow?

The SM2T14A is qualified for standard lead-free reflow profiles with a peak temperature of 260 °C for 10 seconds at the lead termination, per JEDEC J-STD-020. Its STmite package maintains mechanical integrity and electrical performance under these conditions, and no special pre-bake is required for moisture sensitivity level (MSL) handling.

Can SM2T14A be used for bidirectional transient protection?

SM2T14A is unidirectional and must be paired anode-to-anode with a second unit to achieve bidirectional clamping. This configuration provides symmetrical ±19.9 V clamping on data lines like RS-232 or CAN, but doubles capacitance to ~1.3 nF-verify signal integrity impact before deployment in high-speed interfaces.

How does SM2T14A's thermal resistance affect PCB layout?

Its Rth(j-a) = 250 °C/W assumes a specific FR4 pad layout per Figure 11 (1.90 × 1.90 mm copper area). Reducing pad size increases junction temperature rise; adding thermal vias under the cathode pad lowers Rth(j-a) by up to 30%, critical for sustained surge duty cycles exceeding 1 Hz.

Is SM2T14A compliant with AEC-Q200 for automotive use?

No-SM2T14A is not AEC-Q200 qualified. It is designed for commercial and industrial portable equipment. For automotive applications, ST recommends the Automotive-Qualified SMAJ14A-Q or TRANSIL™ AEC-Q200 series, which undergo extended temperature cycling, vibration, and humidity testing per the standard.