Taiwan Semiconductor Corporation TLD8S14AH

Overview

TLD8S14AH from Taiwan Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in DO-218AB package, designed for automotive load dump protection. It features a 14.0 V working stand-off voltage (V_WM), 15.6–17.2 V breakdown voltage (V_BR) at 5 mA, 284 A peak impulse current (I_PPM) with 10/1000 µs waveform, 23.2 V clamping voltage (V_C) at I_PPM, and 6600 W peak pulse power (10/1000 µs), operating up to T_J = 175 °C.

For engineers reviewing the TLD8S14AH datasheet, TLD8S14AH pinout, TLD8S14AH application, or TLD8S14AH equivalent, key selection criteria include its AEC-Q101 qualification, ISO 7637-2/16750-2 compliance, unidirectional polarity, DO-218AB thermal performance (R_θJC = 0.8 °C/W), and precise clamping behavior under 10 ms exponential load dump waveforms.

Technical Context

The TLD8S14AH implements a junction-passivated silicon avalanche structure optimized for high-reliability automotive environments. Its unidirectional configuration provides forward conduction path during overvoltage events while maintaining low leakage (<10 µA at V_WM) and stable V_BR temperature coefficient (0.078 %/°C).

It delivers robust surge immunity per ISO 7637-2 Pulse 5a (load dump) and meets IEC 61000-4-2 Level 4 ESD requirements. Thermal design leverages the DO-218AB case's low junction-to-case resistance (0.8 °C/W) for effective power dissipation during repetitive transients.

Key Specifications

Pinout & Package

Package: DO-218AB surface-mount molded plastic case with matte tin-plated leads, UL 94V-0 rated, polarity marked by cathode band. Weight: 2.691 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ14A and SMCJ14A, the TLD8S14AH uniquely combines AEC-Q101 qualification, 6600 W surge capacity, DO-218AB thermal performance (0.8 °C/W), and ISO 7637-2 compliance-making it the only option qualified for under-hood automotive load dump protection at 14 V system level.

Availability

TLD8S14AH is available at Aetrix Electronics and suitable for automotive engine control units, body control modules, and advanced driver assistance systems requiring stable component supply across extended temperature ranges and high-reliability production cycles.

Supply support for TLD8S14AH 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 Company (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, TVS diodes, and automotive-qualified components with global distribution and AEC-Q certified production lines.

The TLD8S series was developed specifically for automotive 12 V system load dump protection, emphasizing high surge power, thermal robustness, and compliance with ISO 7637-2 and AEC-Q101 standards.

FAQ

What is the clamping voltage of the TLD8S14AH under maximum surge conditions?

The TLD8S14AH has a maximum clamping voltage (V_C) of 23.2 V when subjected to its rated peak impulse current of 284 A with a 10/1000 µs waveform. This value is measured per JEDEC standards and ensures downstream components see no more than 23.2 V during worst-case surge events, making the TLD8S14AH suitable for protecting sensitive 12 V automotive electronics without overvoltage damage.

Is the TLD8S14AH qualified for automotive applications?

Yes, the TLD8S14AH is AEC-Q101 qualified and explicitly validated for automotive use. It meets ISO 7637-2 (Pulse 5a load dump) and ISO 16750-2 surge immunity requirements, operates reliably from –55 °C to +175 °C junction temperature, and carries moisture sensitivity level 1-enabling direct placement in engine control units and other under-hood modules without special handling.

What package does the TLD8S14AH use, and why is it significant?

The TLD8S14AH uses the DO-218AB surface-mount package, which provides superior thermal performance with a junction-to-case thermal resistance (R_θJC) of just 0.8 °C/W. This enables efficient heat dissipation during high-energy transients like load dump, unlike smaller packages such as SMA or SMC. The DO-218AB also supports high surge current (284 A) and is mechanically robust for automotive vibration environments.

How does the TLD8S14AH differ from bidirectional TVS diodes like TLD8S14CAH?

The TLD8S14AH is unidirectional, meaning it conducts only in reverse bias to clamp positive transients on a DC line referenced to ground. In contrast, TLD8S14CAH is bidirectional and protects against both polarities-suitable for AC lines or differential signals. For 12 V automotive battery rail protection, the unidirectional TLD8S14AH offers lower leakage and tighter V_BR tolerance, while TLD8S14CAH would be selected only for symmetric surge threats.

What is the maximum steady-state power dissipation of the TLD8S14AH?

The TLD8S14AH has a steady-state power dissipation (P_D) rating of 8 W at 25 °C ambient, as specified in its absolute maximum ratings. This value applies to continuous DC or low-frequency power dissipation-not transient surges. For surge events, the device relies on its 6600 W peak pulse rating (10/1000 µs), and thermal design must account for transient energy absorption and junction temperature rise using the R_θJC = 0.8 °C/W parameter.