Taiwan Semiconductor Corporation SMCJ17C

Overview

SMCJ17C from Taiwan Semiconductor is a unidirectional 1500W surface-mount transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, with 17V working stand-off voltage (VWM), 18.9–23.1V breakdown voltage (VBR), and 30.5V maximum clamping voltage (VC) at 51A peak pulse current-designed for automotive load-dump and inductive switching protection in power supply rails.

For engineers reviewing the SMCJ17C datasheet, SMCJ17C pinout, SMCJ17C application, or SMCJ17C equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, junction temperature derating above 25°C, moisture sensitivity level (MSL 1), and compatibility with automated SMT placement on 1.6mm-thick PCBs.

Technical Context

The SMCJ17C employs a glass-passivated silicon junction optimized for sub-1ps response to fast transients, delivering consistent clamping across its rated 1ms pulse width per IEC 61000-4-5 and ISO 7637-2 waveforms. Its unidirectional configuration enables polarity-sensitive DC rail protection without reverse conduction during normal operation.

Thermal design relies on low junction-to-case resistance (R_θJC = 10°C/W) and moderate junction-to-ambient resistance (R_θJA = 55°C/W), supporting continuous dissipation up to 5W at 25°C ambient-derated linearly to zero at 150°C junction temperature per Fig.2.

Key Specifications

Pinout & Package

DO-214AB (SMC) package features two terminals: cathode-marked end (band) and anode. Designed for reflow soldering with matte tin-plated leads compliant with J-STD-002; polarity is marked by a cathode band on the molded body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMCJ17C, SMBJ17A offers space savings at the cost of 60% lower surge energy handling, while 1.5KE17C retains full electrical equivalence but sacrifices SMT manufacturability, automotive qualification, and moisture resilience-making SMCJ17C the optimal choice for production-grade automotive and industrial surface-mount systems.

Availability

SMCJ17C is available at Aetrix Electronics and suitable for automotive ECU power rails, industrial PLC inputs, LED driver front-ends, and telecom line interfaces requiring stable component supply, full traceability, and lifecycle continuity.

Supply support for SMCJ17C 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for automotive, industrial, and consumer markets.

The SMCJ series was developed specifically for high-reliability surface-mount transient suppression in harsh environments-emphasizing ISO 7637-2 compliance, MSL 1 robustness, and consistent clamping performance across temperature and surge repetition.

FAQ

What is the clamping voltage of SMCJ17C at its rated peak pulse current?

The SMCJ17C has a maximum clamping voltage (VC) of 30.5 V at 51 A peak impulse current (IPPM), measured under the standardized 10/1000 μs double-exponential waveform per IEC 61000-4-5. This value ensures protected circuits remain within safe operating limits during worst-case surge events. The SMCJ17C maintains this clamping performance across its full operating temperature range from –55°C to +150°C.

Is SMCJ17C unidirectional or bidirectional, and how is polarity identified?

The SMCJ17C is a unidirectional TVS diode, intended for DC rail protection where reverse conduction must be blocked during normal operation. Polarity is marked by a cathode band on the DO-214AB (SMC) package body-the banded end connects to the protected line, and the opposite terminal connects to ground. Bidirectional variants use the "CA" suffix (e.g., SMCJ17CA).

Does SMCJ17C meet automotive transient immunity standards?

Yes, the SMCJ17C meets ISO 7637-2 requirements for Pulses 1, 2a, 2b, 3a, and 3b-covering common automotive transients including load dump, battery disconnection, and inductive switching noise. It is widely deployed in engine control units, body control modules, and infotainment power supplies where certified transient immunity is mandatory.

What is the thermal resistance profile of SMCJ17C, and how does it affect PCB layout?

The SMCJ17C has a junction-to-case thermal resistance (R_θJC) of 10°C/W and junction-to-ambient resistance (R_θJA) of 55°C/W on standard FR-4 with 1 in² copper pad. To maintain TJ ≤ 150°C under 1500W pulses, PCB layout must provide adequate copper area and minimize thermal bottlenecks-especially critical in high-density automotive modules where ambient temperatures exceed 85°C.

Can SMCJ17C be used in place of SMCJ17A, and what is the key difference?

No-SMCJ17C and SMCJ17A are not interchangeable without design review. SMCJ17C is unidirectional with VF = 3.5 V at 100 A forward surge, while SMCJ17A is also unidirectional but specified with lower VBR tolerance (18.9–20.9 V vs. 18.9–23.1 V) and slightly lower clamping (27.6 V). The SMCJ17C provides broader breakdown margin and higher surge robustness, making it preferred for mission-critical applications.