STMicroelectronics SMC30J24CA

Overview

SMC30J24CA from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode designed for high-energy ESD and surge protection in DC power rails and signal lines. It delivers 3000 W peak pulse power (10/1000 µs), clamps at 38.9 V (max) under 122 A surge, and operates up to 175 °C junction temperature - enabling robust protection in industrial power supplies, telecom interfaces, and automotive body electronics.

For engineers reviewing the SMC30J24CA datasheet, SMC30J24CA pinout, SMC30J24CA application, or SMC30J24CA equivalent, key selection criteria include its 24 V standoff voltage, bidirectional polarity, low 0.2 µA leakage at 25 °C, JEDEC-standard SMC package, and IEC 61000-4-2 ±30 kV contact/air discharge compliance.

Technical Context

This planar-junction TVS diode uses silicon avalanche technology to provide fast-response clamping (<1 ns) against electrostatic discharge (IEC 61000-4-2 Level 4), electrical fast transients (IEC 61000-4-4 Level 4), and lightning-induced surges. Its bidirectional configuration protects AC-coupled or floating lines without polarity dependency.

The device features a dynamic resistance of 31.1 mΩ (typical), enabling precise voltage clamping under high-current transients, and exhibits stable thermal performance with α_T = 9.6 × 10⁻⁴/°C for V_CL drift compensation across −55 °C to +175 °C operating range.

Key Specifications

Pinout & Package

SMC30J24CA is housed in a JEDEC-standard SMC (DO-214AB) surface-mount package with matte tin-plated leads, optimized for reflow soldering per J-STD-020 MSL Level 1. The package measures 7.75–8.15 mm × 5.55–6.25 mm × 2.45 mm max height and supports thermal dissipation via copper land pads per IPC7531 footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional TVS protection applications.

Compared with SMBJ24CA and 1.5KE24CA, SMC30J24CA uniquely combines 3000 W surge capability, SMT-compatible SMC packaging, and sub-µA leakage - making it the sole option for high-reliability 24 V DC systems requiring simultaneous high power, low leakage, and automated manufacturability.

Availability

SMC30J24CA is available at Aetrix Electronics and suitable for industrial power supply inputs, automotive body control modules, telecom PoE interfaces, and renewable energy inverter DC links requiring stable component supply and long-term lifecycle support.

Supply support for SMC30J24CA 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 transient immunity in harsh-environment power electronics - emphasizing reliability under repeated surge stress, high-temperature operation, and compliance with international EMC standards.

FAQ

What is the maximum clamping voltage of SMC30J24CA under a 10/1000 µs surge?

The maximum clamping voltage (V_CL) is 38.9 V at 122 A for a 10/1000 µs waveform, measured at T_j = 25 °C. This value increases with junction temperature per α_T = 9.6 × 10⁻⁴/°C, reaching ~42.5 V at 125 °C ambient under full surge conditions.

Is SMC30J24CA compatible with lead-free reflow soldering?

Yes - it is qualified for lead-free reflow per J-STD-020 MSL Level 1, with a peak reflow temperature of 240–245 °C for ≤60 seconds. The matte tin-plated leads and ECOPACK-compliant construction ensure reliable wetting and intermetallic formation without whisker risk.

How does the bidirectional configuration affect circuit layout?

SMC30J24CA has symmetrical terminals (no anode/cathode marking distinction), allowing placement across any two nodes needing bidirectional protection - such as differential signal pairs or floating power rails. No orientation-dependent routing is required, simplifying layout and reducing design errors.

Can SMC30J24CA replace unidirectional TVS diodes like SMC30J24A?

No - SMC30J24CA is strictly bidirectional and cannot substitute for unidirectional types in DC-biased circuits (e.g., 24 V supply-to-ground). Using it in place of SMC30J24A would allow reverse conduction during normal operation, risking short-circuit failure. Polarity must match application topology.