STMicroelectronics SMC30J64A

Overview

SMC30J64A 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 103 V (max) under 832 A surge current, and features low leakage (0.2 µA at 25 °C) and high junction temperature capability (T_j up to 175 °C). It is used in industrial power supplies and telecom interface circuits requiring IEC 61000-4-2 (±30 kV contact/air) and IEC 61000-4-4 level 4 (4 kV) compliance.

For engineers reviewing the SMC30J64A datasheet, SMC30J64A pinout, SMC30J64A application, or SMC30J64A equivalent, key selection criteria include standoff voltage (64 V), clamping voltage (103 V), surge current rating (832 A), thermal robustness (175 °C T_j), and SMC package compatibility with IPC7531 footprint - all critical for reliable overvoltage protection in harsh environments.

Technical Context

The SMC30J64A employs planar junction silicon technology optimized for low dynamic resistance (R_D = 29.1 mΩ) and stable clamping across temperature. Its unidirectional configuration provides asymmetric breakdown behavior ideal for DC-biased lines where reverse conduction must be blocked until specified V_BR (71.3–78.8 V) is exceeded.

It meets JEDEC-registered SMC package standards and supports reflow soldering per J-STD-020 MSL level 1. Electrical performance is characterized at 25 °C and derated above ambient using α_T = 10.5 × 10⁻⁴/°C for both V_BR and V_CL, enabling accurate clamping prediction up to 175 °C junction temperature.

Key Specifications

Pinout & Package

The SMC30J64A is housed in a JEDEC-registered SMC (DO-214AB) surface-mount package with matte tin-plated leads and IPC7531-compliant footprint. Dimensions: 7.75–8.15 mm (E), 5.55–6.25 mm (D), 1.90–2.45 mm (A1), and 0.75–1.50 mm (L).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ64A and 1.5KE68A, the SMC30J64A offers 5× higher surge power handling, tighter V_CL consistency at high current, and full SMT manufacturability - making it the sole choice for new industrial and telecom designs demanding 3000 W IEC 61000-4-4 compliance.

Availability

SMC30J64A is available at Aetrix Electronics and suitable for industrial power supplies, telecom interface protection, automotive body control modules, and smart metering systems requiring stable component supply and long-term lifecycle assurance.

Supply support for SMC30J64A 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 SMC30J series belongs to ST's high-power TVS portfolio, engineered specifically for robust, high-reliability surge immunity in mission-critical infrastructure where thermal stability and IEC/UL certification are mandatory.

FAQ

What is the maximum clamping voltage of SMC30J64A under a 10/1000 µs surge?

The maximum clamping voltage (V_CL) is 103 V when subjected to an 832 A peak pulse current with a 10/1000 µs waveform. This value is measured at T_j = 25 °C and scales linearly with junction temperature using α_T = 10.5 × 10⁻⁴/°C, reaching ~112 V at 175 °C.

Is SMC30J64A suitable for bidirectional signal line protection?

No - SMC30J64A is unidirectional and blocks reverse current until breakdown occurs. For bidirectional protection (e.g., USB, RS-485), the SMC30J64CA variant must be used. Using the 'A' version on AC-coupled or floating lines risks forward conduction and unintended clamping.

Does SMC30J64A require special PCB layout considerations?

Yes - minimize trace inductance between the TVS and protected node by placing it directly across the input terminals with short, wide copper pours. Use ≥2 cm² of copper per lead (per Figure 12) to maintain R_th(j-a) ≤ 4.5 °C/W and prevent thermal runaway during repeated surges.

Can SMC30J64A replace older P6KE68A devices in existing designs?

Only with validation - while both have ~68 V V_BR, SMC30J64A delivers 3000 W vs. P6KE68A's 600 W, has lower V_CL (103 V vs. 112 V), and uses SMC instead of DO-15. Layout, thermal relief, and surge profile must be re-evaluated; direct drop-in replacement is not guaranteed.