Taiwan Semiconductor Corporation SMDJ17AH

Overview

SMDJ17AH from Taiwan Semiconductor is a unidirectional 3000W surface-mount transient voltage suppressor (TVS) diode with a 17V working stand-off voltage, 18.9–20.9V breakdown voltage at 1mA test current, and 27.6V maximum clamping voltage at 108.7A peak pulse current. It is AEC-Q101 qualified and designed for automotive and industrial ESD/transient protection in DC power rails and signal lines.

For engineers reviewing the SMDJ17AH datasheet, SMDJ17AH pinout, SMDJ17AH application, or SMDJ17AH equivalent, this device delivers certified automotive-grade surge immunity per ISO 7637-2 (Pulse 1/2a/2b/3a/3b), sub-1ps response time, DO-214AB (SMC) package compatibility, and robust thermal performance (R_θJA = 75°C/W).

Technical Context

The SMDJ17AH operates as a unidirectional avalanche diode, conducting only in reverse bias above its breakdown threshold to clamp transient energy into ground. Its glass-passivated junction ensures stable V_BR tolerance (±5%) and low leakage (<5µA at 17V), while its single-die DO-214AB construction supports high peak pulse power (3000W @ 1ms) without thermal runaway.

Designed for automated SMT placement, it meets J-STD-020 moisture sensitivity level 1 and JESD 201 Class 2 whisker resistance. Its 175°C max junction temperature and -55°C to +175°C operating range enable use in under-hood automotive modules and industrial motor drives where ambient temperatures exceed 125°C.

Key Specifications

Pinout & Package

Package: DO-214AB (SMC), surface-mount, unidirectional configuration with cathode band marking. Matte tin-plated leads, UL 94V-0 molding compound, 0.290g weight.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SAC17 and SMCJ17A, the SMDJ17AH provides certified automotive reliability, tighter V_BR tolerance, and guaranteed ISO 7637-2 compliance-making it the preferred choice for safety-critical 12V/24V power rail protection where qualification evidence is mandatory.

Availability

SMDJ17AH is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC input cards, and telecom power supply outputs requiring stable component supply, full traceability, and long-term lifecycle support.

Supply support for SMDJ17AH 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, serving global automotive, industrial, and consumer markets since 1979.

The SMDJ series is part of TSC's AEC-Q101-qualified TVS portfolio, engineered specifically for high-energy transient suppression in harsh-environment automotive and industrial power systems.

FAQ

What is the maximum clamping voltage of the SMDJ17AH under rated surge conditions?

The SMDJ17AH has a maximum clamping voltage (V_C) of 27.6 V when subjected to its peak pulse current (I_PPM) of 108.7 A, measured using the standardized 10/1000 µs waveform. This value is guaranteed across temperature and ensures downstream components see no more than 27.6 V during a 3000W transient event. The SMDJ17AH maintains this clamping performance consistently due to its glass-passivated junction and thermally optimized DO-214AB package.

Is the SMDJ17AH suitable for bidirectional transient protection?

No-the SMDJ17AH is a unidirectional TVS diode intended for DC power line protection where polarity is fixed. For bidirectional applications (e.g., AC lines or data buses), the SMDJ17CAH variant must be used. The SMDJ17AH features a cathode band marking and conducts only in reverse bias; applying significant forward voltage may cause unintended conduction or degradation. Always verify polarity alignment before integrating the SMDJ17AH into your design.

Does the SMDJ17AH require special handling during PCB assembly?

No-the SMDJ17AH is rated at moisture sensitivity level (MSL) 1 per J-STD-020, meaning it can be stored indefinitely at ambient conditions and placed directly into reflow without baking or dry-packaging. Its matte tin-plated leads comply with J-STD-002 for solderability, and its DO-214AB footprint aligns with standard SMC land patterns. The SMDJ17AH is fully compatible with automated pick-and-place and lead-free reflow profiles up to 260°C peak.

How does the SMDJ17AH compare to standard SMAJ-series TVS diodes?

The SMDJ17AH delivers 3000W peak power-double the 1500W rating of SMAJ17A-while maintaining identical DO-214AB packaging and electrical parameters (V_WM, V_BR, V_C). This enables drop-in upgrades in space-constrained layouts without PCB redesign. The SMDJ17AH also adds AEC-Q101 qualification and ISO 7637-2 compliance not found in most SMAJ variants. For new designs demanding higher surge immunity, the SMDJ17AH is the direct performance-enhanced replacement.

What is the junction-to-lead thermal resistance (R_θJL) of the SMDJ17AH, and why does it matter?

The SMDJ17AH has a typical junction-to-lead thermal resistance (R_θJL) of 15°C/W, measured from die to soldered lead termination. This low value indicates efficient heat transfer from the silicon junction to the PCB copper, enabling effective power dissipation during repetitive transients. When designing high-reliability systems-especially in automotive under-hood locations-this parameter directly informs minimum copper area and thermal via requirements to maintain T_J ≤ 175°C. The SMDJ17AH's R_θJL supports robust thermal design without external heatsinks.