STMicroelectronics SMC50J11CA

Overview

SMC50J11CA from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode designed for high-energy ESD and surge protection in power and signal lines. It features a standoff voltage (VRM) of 11 V, clamping voltage (VCL) of 18 V at 27.5 A (10/1000 µs), peak pulse power of 5000 W, and operates up to 175 °C junction temperature - ideal for industrial power supplies and automotive body electronics requiring robust IEC 61000-4-2/4-4 compliance.

For engineers reviewing the SMC50J11CA datasheet, SMC50J11CA pinout, SMC50J11CA application, or SMC50J11CA equivalent, key selection criteria include its bidirectional configuration, low leakage (0.2 µA at 25 °C), JEDEC-registered SMC package, and verified 30 kV contact/air discharge immunity per IEC 61000-4-2 Level 4.

Technical Context

The SMC50J11CA uses planar silicon avalanche technology to deliver precise breakdown at 12.3–13.7 V (VBR min/max @ IBR = 1 mA), with dynamic resistance (RD) of 7.57 mΩ enabling tight clamping under fast transients. Its thermal design supports sustained operation at Tj = 175 °C, validated via JEDEC JESD22-A104 temperature cycling and J-STD-020 MSL Level 1 reflow compatibility.

As a bidirectional TVS, it symmetrically suppresses positive and negative surges without polarity dependence, making it suitable for AC-coupled interfaces and differential buses. The device meets IEC 61000-4-4 Level 4 (4 kV), exceeds IEC 61000-4-2 Level 4 (30 kV air/contact), and maintains <0.2 µA reverse leakage at VRM = 11 V and 25 °C - critical for low-power sensor and MCU I/O protection.

Key Specifications

Pinout & Package

SMC50J11CA is housed in a JEDEC-registered SMC (DO-214AB) surface-mount package with matte tin-plated leads, footprint-compatible with IPC7531 guidelines. The bidirectional structure has no anode/cathode polarity marking beyond the cathode bar (per Table 6 marking "EAU"), and both terminals are electrically symmetrical.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ11CA and SAC11CA, SMC50J11CA offers the optimal balance of low clamping voltage (18 V), ultra-low leakage (0.2 µA), and full 5000 W surge capability in a thermally robust SMC package - making it preferred for high-reliability industrial and automotive power rail protection where thermal stability and ESD margin are critical.

Availability

SMC50J11CA is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, telecom remote radio units, and smart energy meter interfaces requiring stable component supply across extended temperature and high-surge environments.

Supply support for SMC50J11CA 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, designing and manufacturing analog, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The SMC50J TVS series targets high-reliability surge protection in harsh environments, emphasizing thermal robustness (175 °C Tj), low leakage, and IEC/ISO compliance for mission-critical power and communication interfaces.

FAQ

What is the difference between SMC50J11A and SMC50J11CA?

SMC50J11A is unidirectional (anode-cathode asymmetry), conducting only in reverse bias, while SMC50J11CA is bidirectional - symmetric conduction for both polarities. This makes the CA version suitable for AC lines, differential buses, and floating grounds where polarity is undefined or alternating.

Can SMC50J11CA be used in parallel for higher surge current handling?

No - TVS diodes like SMC50J11CA exhibit parameter spread (e.g., VBR tolerance ±5%), causing uneven current sharing and potential thermal runaway. For higher current, select a single higher-rated device (e.g., SMC50J12CA or SMC50J13CA) or use external current-sharing resistors with careful derating.

Does SMC50J11CA require a heatsink in standard PCB layouts?

No - the SMC package's thermal resistance (Rth(j-a) ≈ 50 °C/W on 1 cm² copper) and 175 °C max Tj allow safe operation without heatsinks under typical 5000 W surge duty cycles. However, ≥2 cm² copper pour per pad is recommended to sustain repeated surges and minimize junction temperature rise.

Is SMC50J11CA compatible with lead-free reflow processes?

Yes - it is qualified per J-STD-020 MSL Level 1 and supports ST's recommended reflow profile (peak 240–245 °C, 60–90 sec above 217 °C), including standard lead-free SAC305 solder. Matte tin plating ensures reliable wetting and intermetallic formation without whisker risk (JESD201 Class 2).