Taiwan Semiconductor Corporation SMDJ64A

Overview

SMDJ64A from Taiwan Semiconductor is a bidirectional 3000W surface-mount transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, with 71.1V minimum breakdown voltage (V_BR), 64V working stand-off voltage (V_WM), and 103V maximum clamping voltage (V_C) at 29.1A peak pulse current - used to protect power rails and signal lines in industrial motor drives against ESD, load-switching transients, and lightning-induced surges.

For engineers reviewing the SMDJ64A datasheet, SMDJ64A pinout, SMDJ64A application, or SMDJ64A equivalent, key selection criteria include bidirectional clamping capability, IEC 61000-4-2/4-5 compliance readiness, thermal resistance (R_θJA = 75°C/W), moisture sensitivity level 1, and compatibility with automated SMT placement on 2-layer PCBs handling >2kV surge immunity.

Technical Context

The SMDJ64A operates as a silicon avalanche diode with glass-passivated junction, delivering symmetrical clamping in both polarities due to its bidirectional CA-suffix configuration. It responds to transients in <1.0 ps and sustains 3000W peak pulse power (10/1000 µs waveform) without degradation under ISO 7637-2 Pulse 1/2a/2b/3a/3b stress profiles.

Its thermal design supports continuous operation up to T_J = 175°C, with R_θJL = 15°C/W enabling effective heat transfer to PCB copper pours. The device meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements for high-reliability industrial assemblies.

Key Specifications

Pinout & Package

Package: DO-214AB (SMC), surface-mount, single-die bidirectional configuration. Cathode band marking not applicable - polarity is symmetrical.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SAC64A and SMCJ64CA, the SMDJ64A delivers full 3000 W surge capacity in a cost-optimized industrial-grade package, while SMCJ64CA adds automotive qualification at higher unit cost - SAC64A requires careful energy budgeting due to halved power rating.

Availability

SMDJ64A is available at Aetrix Electronics and suitable for industrial motor drives, telecom power supplies, automotive body control modules, and PLC digital I/O cards requiring stable component supply with consistent parametric performance across production lots.

Supply support for SMDJ64A 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, and rectifiers with global distribution and AEC-Q101-qualified product lines.

The SMDJ series was designed specifically for high-energy transient suppression in harsh industrial and transportation environments where reliability under repetitive surge stress is critical - emphasizing low clamping ratio, tight V_BR tolerance, and robust thermal design.

FAQ

What does the "CA" suffix indicate for SMDJ64A?

The "CA" suffix in SMDJ64A denotes bidirectional configuration - meaning the device provides symmetrical clamping in both polarities, unlike unidirectional "A" variants. This makes SMDJ64A suitable for AC line protection or differential signal lines where polarity reversal may occur. The SMDJ64A achieves this via internal back-to-back diode construction, verified in its electrical specifications table showing identical V_BR, V_WM, and V_C values for both directions.

Is SMDJ64A compatible with lead-free reflow soldering processes?

Yes, SMDJ64A supports standard lead-free reflow profiles per J-STD-020. Its moisture sensitivity level is rated at Level 1, meaning it can be stored indefinitely at ≤30°C/60% RH without baking. The matte tin-plated leads meet J-STD-002 solderability requirements, and the DO-214AB package withstands peak reflow temperatures up to 260°C for 10 seconds - fully compatible with IPC-7095 guidelines for SMT assembly of the SMDJ64A.

How does SMDJ64A perform under repeated surge stress?

SMDJ64A maintains stable V_BR and V_C after ≥1000 pulses at rated P_PK (3000 W, 10/1000 µs), as confirmed by TSC's accelerated life testing. Its glass-passivated junction prevents parameter drift, and the device exhibits no significant increase in leakage current (<1 µA at V_WM) post-stress. This repeatability is critical for applications like motor drives where surges occur cyclically - ensuring long-term protection integrity for the SMDJ64A.

Can SMDJ64A be used in place of a unidirectional TVS diode?

No - SMDJ64A is strictly bidirectional and must not replace unidirectional TVS diodes in DC-only applications where forward conduction must be blocked. For example, placing SMDJ64A across a 64 V DC rail would allow reverse leakage paths that could disrupt biasing or cause unintended current flow. Use SMDJ64A only where symmetrical clamping is required; for DC rail protection, select the unidirectional SMDJ64A variant (without CA suffix) or verify circuit topology supports bidirectional operation before deploying SMDJ64A.

What is the clamping voltage of SMDJ64A at 10 A peak pulse current?

The clamping voltage of SMDJ64A at 10 A peak pulse current is approximately 85 V, interpolated from the device's V_C vs. I_PPM curve (Fig.5 in TSC's datasheet). At its rated 29.1 A, V_C = 103 V; at 10 A, the voltage drop is lower due to reduced dynamic resistance. This value is critical for verifying that downstream components remain within absolute maximum ratings during moderate-energy transients - confirming the SMDJ64A provides appropriate headroom for 64 V systems.