Taiwan Semiconductor Corporation SA20H

Overview

SA20H from Taiwan Semiconductor is a unidirectional AEC-Q101-qualified transient voltage suppressor (TVS) diode in DO-204AC (DO-15) package, rated for 500W peak pulse power at 10/1000μs, with 20V working stand-off voltage, 22.2–27.1V breakdown voltage at 1mA test current, and clamping voltage of 35.5V at 14A peak pulse current. It protects automotive power rails and signal lines against ESD and load dump transients.

For engineers reviewing the SA20H datasheet, SA20H pinout, SA20H application, or SA20H equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, clamping performance under standardized surge waveforms, thermal derating behavior, and direct alternatives for automotive-grade overvoltage protection design.

Technical Context

The SA20H operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its V_BR range (22.2–27.1V), then clamping to ≤35.5V at 14A IPPM to limit energy delivered to downstream circuitry. Its low leakage (<1μA @ 20V) ensures minimal standby power loss in always-on automotive modules.

Designed for 10/1000μs surge compliance per IEC 61000-4-5 and ESD immunity per IEC 61000-4-2, it features <1.0ps response time from 0V to V_BR, enabling protection of fast-edge microcontroller I/O and CAN transceivers without signal distortion.

Key Specifications

Pinout & Package

Package: DO-204AC (DO-15), axial leaded, epoxy-molded case with cathode band marking for unidirectional polarity. Meets UL 94V-0 flammability and JESD201 Class 2 whisker resistance requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ20A and 1.5SMC20A, SA20H offers AEC-Q101 qualification out-of-box, tighter V_BR tolerance (22.2–27.1V vs. ±5%), and DO-15 axial leads optimized for through-hole automotive harness connections-making it preferred for new automotive ECUs where qualification traceability and mechanical robustness are mandatory.

Availability

SA20H is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor signal conditioning circuits, and LED lighting driver modules requiring stable component supply with full AEC-Q101 documentation and lot traceability.

Supply support for SA20H 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, specializing in TVS diodes, rectifiers, MOSFETs, and power management devices.

The SA Series was developed specifically for automotive-grade transient suppression, emphasizing AEC-Q101 reliability, tight parametric tolerances, and robust surge endurance in harsh under-hood environments.

FAQ

What does the "H" suffix in SA20H signify?

The "H" suffix in SA20H indicates full AEC-Q101 qualification per Rev D requirements, including stress testing for temperature cycling, humidity bias, high-temperature operating life, and ESD. Unlike standard SA20 variants, SA20H provides certified test reports and process controls required for automotive Tier 1 supplier BOMs. SA20H is not a mechanical variant-it shares identical electrical specs and DO-15 packaging with SA20 but adds automotive reliability assurance.

Is SA20H bidirectional or unidirectional?

SA20H is a unidirectional TVS diode, as confirmed by its marking diagram (cathode band), absence of bidirectional V_BR symmetry in datasheet tables, and specification of forward voltage (V_F = 3.5V @ 35A). It protects against reverse-polarity transients only and must be oriented with cathode toward the protected line. For bidirectional protection, SA20AH would be required-but that part is not listed in the SA Series table and is not offered by Taiwan Semiconductor.

What is the maximum clamping voltage of SA20H under surge conditions?

The maximum clamping voltage of SA20H is 35.5V at 14A peak pulse current (I_PPM) under the standardized 10/1000μs waveform. This value is measured per ANSI/IEEE C62.35 and represents the upper bound of voltage seen by downstream components during worst-case surge events. It remains stable across the full operating junction temperature range (−55°C to +175°C), with no additional derating required for thermal effects on clamping performance.

Can SA20H replace SA20 in an existing design?

Yes, SA20H is a drop-in replacement for SA20 in terms of pinout, package (DO-204AC), and all electrical parameters-including V_WM, V_BR, V_C, and P_PK. The only difference is AEC-Q101 qualification: SA20H undergoes additional automotive-specific reliability testing and comes with certified documentation. No PCB or schematic changes are needed, but SA20H should be specified where automotive qualification is contractually or functionally required.

What is the junction-to-ambient thermal resistance (R_θJA) of SA20H?

Taiwan Semiconductor does not publish R_θJA for SA20H in the provided documentation. However, based on DO-204AC (DO-15) package data and thermal derating curves (Fig.2), the device achieves 3W steady-state power dissipation at T_L = 75°C with 9.5mm lead lengths on 10×10mm copper pads. For precise thermal modeling, users should apply JEDEC JESD51-2 compliant board layouts and refer to the pulse derating curve to determine safe average power under repetitive surge conditions.