Taiwan Semiconductor Corporation SMAJ100CAH

Overview

SMAJ100CAH from Taiwan Semiconductor is a bidirectional 400W transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for automotive-grade surge protection with 100V working stand-off voltage, 111–136V breakdown voltage at 1mA test current, and 162V maximum clamping voltage at 1.9A peak impulse current. It meets ISO 7637-2 Pulse 1/2a/2b/3a/3b and is AEC-Q101 qualified for under-hood power electronics.

For engineers reviewing the SMAJ100CAH datasheet, SMAJ100CAH pinout, SMAJ100CAH application, or SMAJ100CAH equivalent, this device serves as a robust, surface-mount overvoltage clamp for DC bus lines in automotive DC/DC converters, industrial SMPS inputs, LED driver rails, and battery-connected control modules where fast (<1ps) response, low leakage (<1µA), and high-energy pulse handling are required.

Technical Context

This bidirectional TVS operates symmetrically in both polarities, enabling single-device protection of floating or AC-coupled signal/power lines without polarity concerns. Its glass-passivated junction ensures stable V_BR and low leakage across -55°C to +150°C operating range, while the DO-214AC package supports automated placement and meets JESD201 Class 2 whisker resistance.

The device delivers 400W peak pulse power (10/1000µs waveform) up to 78V V_WM; above that, derating applies-SMAJ100CAH maintains 300W capability per spec sheet footnote. Clamping occurs at 162V (max) under 1.9A IPPM, limiting transient energy dissipation in protected circuits with predictable voltage overshoot.

Key Specifications

Pinout & Package

DO-214AC (SMA) surface-mount package: molded epoxy case with matte tin-plated leads, polarity indicated by cathode band (bidirectional symmetry means band denotes common reference point, not unidirectional polarity). Weight ≈ 0.060g; UL 94V-0 rated compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ100CAH, the Littelfuse SMAJ100CA offers identical clamping performance but omits automotive qualification-making it a cost-effective alternative for non-automotive use. The Vishay SMAJ100CAHE3/5A matches key parameters and environmental compliance but lacks published AEC-Q101 evidence, requiring customer validation for automotive deployment.

Availability

SMAJ100CAH is available at Aetrix Electronics and suitable for automotive DC/DC converters, industrial switch-mode power supplies, and LED driver power rails requiring stable component supply, AEC-Q101 assurance, and ISO 7637-2 compliance.

Supply support for SMAJ100CAH 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, TVS diodes, rectifiers, and automotive-qualified components since 1979.

SMAJxxCAH series belongs to TSC's AEC-Q101-qualified transient suppression portfolio, engineered specifically for harsh-environment automotive and industrial power rail protection with emphasis on clamping precision, thermal stability, and SMT manufacturability.

FAQ

What does the 'CAH' suffix indicate in SMAJ100CAH?

The 'CAH' suffix in SMAJ100CAH denotes a bidirectional configuration (C), AEC-Q101 qualification (A), and halogen-free construction (H). Unlike unidirectional 'AH' variants, SMAJ100CAH provides symmetrical clamping in both voltage polarities-critical for protecting floating nodes, differential signals, or AC-coupled power paths. This makes SMAJ100CAH distinct from SMAJ100AH, which is unidirectional and unsuitable for bipolar surge scenarios.

How does SMAJ100CAH perform under repeated surge conditions?

SMAJ100CAH is rated for non-repetitive surges per the 10/1000µs waveform (Fig.5); its 400W peak pulse power applies to single events. For repetitive transients, derating per Fig.2 is mandatory-above 25°C ambient, power must be reduced linearly to 0W at 150°C. No guaranteed lifetime cycle count is specified; each surge event consumes partial junction energy, and cumulative stress requires system-level thermal design to avoid premature failure of SMAJ100CAH.

Can SMAJ100CAH replace SMAJ100A in an existing design?

No-SMAJ100CAH cannot directly replace SMAJ100A. SMAJ100A is unidirectional with cathode-anode polarity, while SMAJ100CAH is bidirectional with symmetrical terminals. Swapping them risks incorrect clamping behavior: SMAJ100CAH would conduct during normal forward bias in unidirectional circuits, causing short-circuit failure. Always verify circuit topology and polarity requirements before substituting SMAJ100CAH for any unidirectional variant.

What is the maximum clamping voltage of SMAJ100CAH at its rated peak current?

The maximum clamping voltage of SMAJ100CAH is 162 V at 1.9 A peak impulse current (I_PPM) under the standardized 10/1000µs waveform. This value is measured per test condition Note 2 in the datasheet and represents the worst-case voltage seen by downstream components during a full-rated surge. Designers must ensure all protected devices have voltage withstand margins exceeding 162 V to guarantee reliability with SMAJ100CAH.

Is SMAJ100CAH compatible with lead-free reflow soldering profiles?

Yes-SMAJ100CAH is fully compatible with standard lead-free reflow profiles (e.g., JEDEC J-STD-020 Level 1), as confirmed by its moisture sensitivity level (MSL) 1 rating and matte tin-plated leads compliant with J-STD-002. No pre-bake is required, and the DO-214AC package withstands peak temperatures up to 260°C for 30 seconds. This ensures robust solder joint formation without delamination or popcorn effect during SMAJ100CAH assembly.