STMicroelectronics SMC30J26A

Overview

SMC30J26A from STMicroelectronics is a unidirectional transient voltage suppression (TVS) diode designed for high-energy surge protection in DC power rails and signal lines. It delivers 3000 W peak pulse power (10/1000 µs), clamps at 42.1 V (max) under 144 A surge current, and operates up to 175 °C junction temperature - enabling robust protection in industrial power supplies, automotive ECUs, and telecom infrastructure.

For engineers reviewing the SMC30J26A datasheet, SMC30J26A pinout, SMC30J26A application, or SMC30J26A equivalent, key selection criteria include its 26 V standoff voltage, low 0.2 µA leakage at 25 °C, JEDEC-registered SMC package compatibility, and IEC 61000-4-2 ±30 kV ESD immunity - critical for reliable front-end protection in harsh environments.

Technical Context

This planar-junction TVS diode uses silicon avalanche technology to provide fast response (<1 ns) to transients while maintaining low dynamic resistance (34.5 mΩ) and stable clamping performance across temperature. Its unidirectional configuration supports DC-biased applications where reverse polarity is not expected.

The device complies with IEC 61000-4-4 Level 4 (4 kV), exceeds IEC 61000-4-2 Level 4 (±30 kV air/contact discharge), and meets JESD22-B102 E3 solderability and IPC7531 footprint standards - ensuring manufacturability and long-term reliability in automated assembly.

Key Specifications

Pinout & Package

SMC30J26A is housed in a JEDEC-registered SMC (DO-214AB) surface-mount package with matte tin-plated leads. The package measures 7.75–8.15 mm × 5.55–6.25 mm × 2.45 mm max height and features a standard two-terminal configuration optimized for high-current PCB trace routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ26A and 1.5KE27A, SMC30J26A provides triple the surge power handling in an SMT package with tighter VCL control and superior high-temperature stability - making it the preferred choice for next-generation industrial and automotive power protection where space, reliability, and energy rating are jointly constrained.

Availability

SMC30J26A is available at Aetrix Electronics and suitable for industrial power supplies, automotive electronic control units, telecom remote radio units, and smart metering systems requiring stable component supply and long-term lifecycle support.

Supply support for SMC30J26A 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 microcontroller technologies for industrial, automotive, and consumer markets.

The SMC30J series belongs to ST's high-power TVS portfolio, engineered specifically for robust front-end protection in harsh-environment DC power systems where reliability under repeated surge stress is non-negotiable.

FAQ

What is the maximum clamping voltage of SMC30J26A under a 10/1000 µs surge?

The maximum clamping voltage (VCL) of SMC30J26A is 42.1 V when subjected to a 144 A peak pulse current with a 10/1000 µs waveform. This value is measured at 25 °C and remains stable up to 175 °C junction temperature due to its low αT coefficient (9.7 × 10⁻⁴/°C).

Is SMC30J26A compatible with lead-free reflow soldering processes?

Yes, SMC30J26A is qualified for lead-free reflow per J-STD-020 MSL Level 1 and supports peak temperatures up to 245 °C for 20–30 seconds. Its matte tin plating and JEDEC-compliant SMC package ensure reliable wetting and intermetallic formation without voiding or delamination.

How does SMC30J26A differ from its bidirectional counterpart SMC30J26CA?

SMC30J26A is unidirectional and protects only against positive-going transients on DC-biased lines, while SMC30J26CA provides symmetrical clamping for AC or floating signal lines. The CA version has identical VBR, VCL, and PPP ratings but exhibits matched forward/reverse characteristics and higher capacitance (≈100 pF vs. ≈30 pF for A-type at 1 MHz).

Can SMC30J26A be used in parallel to increase surge current handling?

No - paralleling SMC30J26A devices is not recommended due to parameter mismatch (VBR tolerance ±5%) causing uneven current sharing and premature failure of the lower-VBR unit. For higher current needs, select a single higher-rated device such as SMC30J33A or use staged protection with upstream MOVs.