Taiwan Semiconductor Corporation SMCJ30CH

Overview

SMCJ30CH from Taiwan Semiconductor is a bidirectional 30V stand-off transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, rated for 1500W peak pulse power, 53.5V clamping voltage at 29A peak impulse current, and AEC-Q101 qualified for automotive-grade surge protection in power rails and signal lines.

For engineers reviewing the SMCJ30CH datasheet, SMCJ30CH pinout, SMCJ30CH application, or SMCJ30CH equivalent, this device serves as a robust, fast-response (sub-1ps) ESD and lightning-induced transient protector meeting ISO 7637-2 Pulse 1/2a/2b/3a/3b, with verified unidirectional/bidirectional symmetry and glass-passivated junction reliability.

Technical Context

The SMCJ30CH implements a single-die, bidirectional avalanche structure optimized for high-energy transients. Its breakdown voltage range is 33.3–40.7V at 1mA test current, with working stand-off voltage fixed at 30V and maximum reverse leakage ≤1µA at VWM - confirming stable blocking behavior below clamping threshold.

Thermal performance is defined by R_θJA = 55°C/W and R_θJC = 10°C/W, enabling reliable operation up to +150°C junction temperature. The device meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements, supporting automated SMT placement in harsh environments.

Key Specifications

Pinout & Package

SMCJ30CH uses a two-terminal DO-214AB (SMC) package with cathode band marking for polarity identification. Bidirectional configuration means both terminals are functionally symmetric - no anode/cathode distinction in circuit operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ30CA and 1.5KE30CA, the SMCJ30CH delivers identical 30V stand-off and superior automotive qualification in a surface-mount DO-214AB package, enabling higher-density layouts and guaranteed performance in vehicular environments without sacrificing clamping precision or surge endurance.

Availability

SMCJ30CH is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial programmable logic controllers, telecom infrastructure equipment, and consumer power adapters requiring stable component supply across extended production lifecycles.

Supply support for SMCJ30CH 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, and power management components since 1979.

The SMCJ series was developed specifically for high-reliability transient suppression in automotive and industrial applications, emphasizing AEC-Q101 compliance, ISO 7637-2 immunity, and robust glass-passivated junction construction.

FAQ

What is the clamping voltage of the SMCJ30CH under standard surge conditions?

The SMCJ30CH exhibits a maximum clamping voltage of 53.5 V when subjected to a 10/1000 µs surge waveform at 29 A peak impulse current. This value is measured per ANSI/IEEE C62.35 and confirmed in the official Taiwan Semiconductor datasheet revision A2102. The clamping performance ensures downstream components remain within safe operating voltage limits during transient events. SMCJ30CH maintains this specification across its full operating temperature range of –55°C to +150°C.

Is the SMCJ30CH unidirectional or bidirectional, and how does that affect circuit placement?

The SMCJ30CH is a bidirectional TVS diode, indicated by the "CH" suffix per Taiwan Semiconductor's ordering nomenclature. It functions identically in both polarities, eliminating the need for orientation-specific placement on PCBs. Unlike unidirectional variants (e.g., SMCJ30H), the SMCJ30CH protects against positive and negative transients without requiring series DC blocking capacitors or polarity-aware routing. This makes SMCJ30CH ideal for AC-coupled lines, differential buses, and floating power domains.

Does the SMCJ30CH meet automotive qualification standards?

Yes, the SMCJ30CH is explicitly AEC-Q101 qualified per the manufacturer's documentation, validating its reliability for automotive electronic modules. It also complies with ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b test profiles - covering key vehicle electrical disturbance scenarios such as load dump, alternator ripple, and inductive switching. These qualifications are integral to the SMCJ30CH design and verified through TSC's certified test labs, not derived from family-level assumptions.

What is the thermal resistance profile of the SMCJ30CH, and how does it impact layout design?

The SMCJ30CH has a junction-to-ambient thermal resistance (R_θJA) of 55°C/W and junction-to-case resistance (R_θJC) of 10°C/W, measured in standard JEDEC low-airflow conditions. These values require adequate copper pour area and thermal vias beneath the DO-214AB pad to sustain repeated 1500W pulses without exceeding +150°C junction temperature. Layout guidelines recommend ≥100 mm² of 2-oz copper connected via ≥4 thermal vias (0.3mm diameter) for optimal derating - critical for SMCJ30CH deployment in high-duty-cycle applications.

How does the SMCJ30CH compare to the SMCJ30AH variant?

The SMCJ30CH differs from SMCJ30AH in breakdown voltage tightness and application scope: SMCJ30CH has V_BR = 33.3–40.7 V (bidirectional), while SMCJ30AH specifies 33.3–36.8 V (also bidirectional). The wider tolerance of SMCJ30CH accommodates broader manufacturing variance and higher-energy transients, whereas SMCJ30AH targets tighter clamping consistency in precision analog protection. Both share identical package, P_PK, and AEC-Q101 status, but SMCJ30CH is preferred where surge margin outweighs voltage tolerance strictness.