Vishay General Semiconductor - Diodes Division SMC3K30CA-M3/57

Overview

SMC3K30CA-M3/57 from Vishay General Semiconductor is a bidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMC (DO-214AB) package, rated for 3000 W peak pulse power (10/1000 μs), 33.3–36.8 V breakdown voltage, and 48.4 V maximum clamping voltage at 62.0 A surge current. It protects MOSFETs, ICs, and sensor signal lines against inductive switching transients and lightning-induced surges in automotive and industrial systems.

For engineers reviewing the SMC3K30CA-M3/57 datasheet, SMC3K30CA-M3/57 pinout, SMC3K30CA-M3/57 application, or SMC3K30CA-M3/57 equivalent, key selection criteria include its AEC-Q101 qualification, bidirectional polarity, 30 V stand-off voltage, low incremental surge resistance, and UL 497B safety recognition - all critical for robust overvoltage protection in harsh environments.

Technical Context

The SMC3K30CA-M3/57 operates as a clamping-type TVS diode with avalanche breakdown behavior, triggered when reverse voltage exceeds its 33.3–36.8 V V_BR. Its 48.4 V V_C at 62.0 A IPPM ensures predictable voltage limiting during transient events, while its 2.0 μA max reverse leakage at 30 V V_WM minimizes standby power loss.

Designed for surface-mount assembly, it meets J-STD-020 MSL Level 1, supports 260 °C lead-free reflow, and is not recommended for bottom-side wave soldering. Its SMC (DO-214AB) package provides 8.0 mm × 8.0 mm copper pad thermal performance and UL 94 V-0 flammability compliance.

Key Specifications

Pinout & Package

Package: SMC (DO-214AB), surface-mount, bidirectional device with unmarked cathode/anode terminals - polarity identified by device marking code "3BFK" on cathode band end per Vishay standard orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with SMC3K30CA-M3/57, the HM3 variant adds formal automotive qualification traceability without electrical change, while SMC3K33CA-M3/57 trades 3 V higher stand-off for reduced clamping headroom - making each optimal for distinct voltage-margin and compliance requirements.

Availability

SMC3K30CA-M3/57 is available at Aetrix Electronics and suitable for automotive power distribution, industrial sensor signal protection, telecom line interface, and consumer appliance motor control requiring stable component supply and consistent lot-to-lot performance.

Supply support for SMC3K30CA-M3/57 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

Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, optoelectronics, and passive components with emphasis on reliability and application-specific performance.

The SMC3K30CA-M3/57 belongs to Vishay's TRANSZORB® TVS family, engineered for high-power transient suppression in automotive, industrial, and telecom infrastructure where robustness against repetitive surge events is essential.

FAQ

What is the maximum clamping voltage of the SMC3K30CA-M3/57 at its rated peak pulse current?

The SMC3K30CA-M3/57 has a maximum clamping voltage (V_C) of 48.4 V at its rated peak pulse current (I_PPM) of 62.0 A, measured using the standardized 10/1000 μs waveform. This value is guaranteed across the full operating temperature range and defines the upper voltage limit imposed on protected circuits during worst-case transient events. The SMC3K30CA-M3/57 maintains this clamping performance due to its low incremental surge resistance and optimized silicon junction design.

Is the SMC3K30CA-M3/57 suitable for new automotive designs?

No - the SMC3K30CA-M3/57 is designated "Not for New Designs" per Vishay's official documentation (Doc. #89433, Rev. 13-Sep-2022). For new automotive projects, Vishay recommends the AEC-Q101-qualified SMC3K30CAHM3/57 or other HM3-suffix variants. The SMC3K30CA-M3/57 remains viable for legacy production and non-automotive industrial/commercial use where qualification documentation is not required.

What does the "-M3/57" suffix indicate in SMC3K30CA-M3/57?

The "-M3/57" suffix identifies the SMC3K30CA-M3/57 as a commercial-grade, halogen-free, RoHS-compliant version supplied in 7-inch plastic tape-and-reel packaging with a base quantity of 850 units. The "M3" denotes matte tin-plated leads compliant with JESD 201 Class 2 whisker resistance, while "/57" specifies the reel size and packaging format per Vishay's ordering nomenclature.

How does the bidirectional nature of the SMC3K30CA-M3/57 affect its PCB layout?

The SMC3K30CA-M3/57 is inherently bidirectional with no anode/cathode distinction in function - both terminals behave identically under positive or negative transients. PCB layout requires no polarity orientation; the device may be placed symmetrically across differential lines or unidirectional rails. However, the cathode band marking ("3BFK") must still align with the silkscreen indicator for traceability, even though electrical performance is identical in either orientation.

What is the thermal derating behavior of the SMC3K30CA-M3/57 above 25 °C ambient?

The SMC3K30CA-M3/57 follows standard TVS derating curves: its peak pulse power capability decreases linearly above T_A = 25 °C, reaching ~50 % of rated 3000 W at T_J ≈ 125 °C. Derating is governed by junction temperature, not ambient alone; effective PCB copper pad area (recommended 8.0 mm × 8.0 mm) directly impacts thermal resistance. Full derating data is provided in Figure 2 of Vishay Doc. #89433.