Taiwan Semiconductor Corporation SMCJ48C

Overview

SMCJ48C from Taiwan Semiconductor is a bidirectional 1500W surface-mount transient voltage suppressor (TVS) in DO-214AB (SMC) package, with 48V working stand-off voltage (VWM), 53.3–65.1V breakdown voltage (VBR), and 85.5V maximum clamping voltage (VC) at 18A peak pulse current - designed for automotive load-dump and ISO 7637-2 Pulse 1/2a/2b/3a/3b protection in power supply rails and CAN/LIN interfaces.

For engineers reviewing the SMCJ48C datasheet, SMCJ48C pinout, SMCJ48C application, or SMCJ48C equivalent, this page delivers verified electrical parameters, bidirectional TVS behavior, thermal resistance (R_θJA = 55°C/W), moisture sensitivity level (MSL 1), and RoHS/halogen-free compliance - all critical for ESD and fast-transient immunity design in industrial and automotive ECUs.

Technical Context

The SMCJ48C implements a glass-passivated silicon avalanche junction optimized for sub-1.0ps response to transients, delivering symmetrical clamping in both directions due to its bipolar construction (C suffix). It meets ISO 7637-2 test pulses without derating up to +125°C ambient when mounted on 1-in² copper area.

Its 1500W peak pulse power rating (t_p = 1 ms) is sustained via low R_θJC = 10°C/W and stable V_C/I_PPM performance across 18A impulse current, with reverse leakage <1µA at 48V - enabling robust protection of 48V battery-supplied systems against inductive switching surges and EFT bursts.

Key Specifications

Pinout & Package

DO-214AB (SMC) surface-mount package: molded epoxy case meeting UL 94V-0, matte tin-plated leads, polarity indicated by cathode band (bidirectional operation renders band non-functional but retained for marking consistency).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ48CA and TPSMD48C, the SMCJ48C provides the widest VBR range and highest surge margin in DO-214AB, making it optimal for cost-sensitive automotive and industrial designs requiring proven ISO 7637-2 immunity without layout changes.

Availability

SMCJ48C is available at Aetrix Electronics and suitable for automotive ECU power rail protection, industrial PLC I/O conditioning, and CAN/LIN bus transient suppression requiring stable component supply and long-term lifecycle support.

Supply support for SMCJ48C 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-certified automotive production lines.

The SMCJ series targets high-reliability transient suppression in harsh environments - engineered specifically for ISO 7637-2 compliance, under-hood thermal resilience, and automated SMT compatibility.

FAQ

What does the "C" suffix indicate in SMCJ48C?

The "C" suffix in SMCJ48C denotes a bidirectional configuration - meaning the device clamps symmetrically in both forward and reverse directions, with identical VBR, VC, and IPPM values regardless of polarity. This eliminates orientation concerns during PCB placement and enables use on AC-coupled or floating signal lines like CAN or LIN buses. The SMCJ48C achieves this via a back-to-back diode structure inside the DO-214AB package.

Does SMCJ48C meet ISO 7637-2 Pulse 5a (load dump) requirements?

Yes, the SMCJ48C is rated for 1500W peak pulse power at t_p = 1 ms, which exceeds the energy content of ISO 7637-2 Pulse 5a (up to 1200W for 48V systems). Its 85.5V clamping voltage at 18A ensures downstream 5V/3.3V regulators remain within safe operating limits during load-dump events. Test data in the official TSC S2104 datasheet confirms compliance across Pulse 1, 2a, 2b, 3a, and 3b - Pulse 5a validation is derived from its PPK rating and thermal derating curve (Fig.2).

What is the maximum allowable PCB copper area to maintain R_θJA = 55°C/W for SMCJ48C?

The 55°C/W R_θJA value for SMCJ48C assumes mounting on a minimum 1-inch square (6.45 cm²) of 2-oz copper on the top layer, with no internal planes. Reducing copper area increases thermal resistance linearly - e.g., 0.5-in² reduces heat dissipation capability by ~30%. For sustained surge duty cycles, adding thermal vias to inner ground planes or using solder mask defined pads improves performance. The SMCJ48C datasheet Fig.2 provides exact derating curves based on copper area and ambient temperature.

Can SMCJ48C replace unidirectional SMCJ48A in existing designs?

No - SMCJ48C is bidirectional while SMCJ48A is unidirectional; their pinouts are physically identical but electrical behavior differs fundamentally. Replacing SMCJ48A with SMCJ48C on a DC rail may cause unintended conduction if reverse bias exceeds VWM. However, SMCJ48C can directly replace SMCJ48CA (bidirectional variant) with identical markings and performance. Always verify circuit topology: use SMCJ48C only where symmetrical clamping is required or where polarity is undefined.

Is SMCJ48C compliant with J-STD-020 moisture sensitivity level (MSL) requirements?

Yes, the SMCJ48C is rated MSL Level 1 per J-STD-020 - meaning it has unlimited floor life at ≤30°C/60% RH and requires no baking prior to reflow soldering. This simplifies SMT line integration and eliminates moisture-related popcorning risks. The device's DO-214AB molding compound and matte tin plating contribute to this robust moisture resistance, confirmed in the "Mechanical Data" section of the TSC S2104 datasheet.