Taiwan Semiconductor Corporation SMBJ58C

Overview

SMBJ58C from Taiwan Semiconductor is a unidirectional 600W surface-mount transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, designed for high-energy surge protection in automotive and industrial power rails. It features a 58V working stand-off voltage (VWM), 64.4–78.7V breakdown voltage (VBR @ 1mA), and clamps transients to ≤103V at 6.1A peak impulse current (IPP), meeting ISO 7637-2 Pulse 1/2a/2b/3a/3b immunity requirements.

For engineers reviewing the SMBJ58C datasheet, SMBJ58C pinout, SMBJ58C application, or SMBJ58C equivalent, this page delivers verified electrical parameters, thermal performance data, bidirectional marking context (C suffix), clamping behavior under 10/1000µs surges, and real-world ESD/inductive-switching protection use cases - all critical for robust front-end circuit hardening.

Technical Context

The SMBJ58C is a single-die, glass-passivated junction TVS diode optimized for fast response (<1.0ps) and low leakage (<1µA @ VWM). Its unidirectional configuration provides polarity-sensitive clamping with forward voltage VF = 3.5V @ 50A (per series specification), enabling integration into DC power lines where reverse conduction must be blocked.

Thermally, it supports operation from –55°C to +150°C junction temperature, with R_θJC = 10°C/W and R_θJA = 55°C/W. It meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability standards, confirming suitability for high-reliability PCB assembly environments.

Key Specifications

Pinout & Package

DO-214AA (SMB) package: molded plastic case with cathode band marking; polarity-sensitive unidirectional device; terminals are anode (unmarked end) and cathode (banded end); weight ≈ 0.090 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ58A and SMCJ58A, the SMBJ58C offers optimal balance of 600W surge capacity, DO-214AA thermal performance (R_θJA = 55°C/W), and industry-standard footprint - making it ideal for cost-sensitive, volume automotive and industrial designs where precise 600W clamping is required without over-engineering.

Availability

SMBJ58C is available at Aetrix Electronics and suitable for automotive infotainment power supplies, industrial PLC input modules, LED lighting drivers, and RS-485 sensor interfaces requiring stable component supply across multi-year production cycles.

Supply support for SMBJ58C 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated Taiwanese manufacturer specializing in discrete semiconductors, including TVS diodes, rectifiers, and MOSFETs, with ISO/TS 16949 certification for automotive-grade production.

The SMBJ series was developed specifically for high-reliability transient suppression in automotive and industrial environments, emphasizing ISO 7637-2 compliance, moisture resilience, and automated assembly compatibility.

FAQ

What does the 'C' suffix in SMBJ58C indicate?

The 'C' suffix in SMBJ58C denotes a unidirectional configuration with cathode-band polarity marking. Unlike bidirectional variants (e.g., SMBJ58CA), the SMBJ58C conducts only in reverse bias during overvoltage events and blocks forward current - essential for DC power rail protection where polarity must be preserved. This distinguishes SMBJ58C from CA-suffixed parts used in AC-coupled or bipolar signal paths.

How does SMBJ58C perform under repeated surge stress?

SMBJ58C is rated for non-repetitive 10/1000µs surges up to 600W; its datasheet does not specify repetitive surge capability. For applications involving frequent transients, thermal derating per Figure 2 must be applied - e.g., at 75°C ambient, peak power drops to ~420W. The SMBJ58C's R_θJA = 55°C/W and TJ max = +150°C define its sustainable duty cycle; continuous operation requires layout-level heatsinking or spacing to limit junction temperature rise.

Is SMBJ58C compliant with automotive EMC standards?

Yes, SMBJ58C meets ISO 7637-2 Pulse 1 (inductive switch-off), Pulse 2a/2b (battery disconnection), and Pulse 3a/3b (capacitive coupling) test profiles - key requirements for automotive electronic control units. Its <1.0ps response time and 103V clamping voltage ensure downstream components remain within safe operating area during standardized vehicle-level immunity tests.

What is the maximum allowable mounting density for SMBJ58C on a PCB?

Due to its R_θJA = 55°C/W and 3W steady-state power dissipation limit, SMBJ58C requires minimum copper area and spacing to avoid thermal crowding. Taiwan Semiconductor recommends ≥25 mm² of 1oz copper connected to each terminal, with ≥1.5 mm clearance to adjacent heat sources. High-density layouts must verify junction temperature via thermal simulation or IR imaging - especially when multiple SMBJ58C devices operate simultaneously near 70°C ambient.

Can SMBJ58C replace SMBJ58A in an existing design?

No - SMBJ58C and SMBJ58A differ in breakdown voltage range: SMBJ58C has VBR = 64.4–78.7V, while SMBJ58A is tighter at 64.4–71.2V. Substituting SMBJ58C may result in earlier clamping and increased leakage under nominal 58V operation. The SMBJ58C also lacks the "A"-grade tighter tolerance; use only if the design accommodates the wider VBR spread and validates clamping behavior at system level.