Taiwan Semiconductor Corporation SA90

Overview

SA90 from Taiwan Semiconductor is a unidirectional 500W transient voltage suppressor (TVS) diode in DO-204AC (DO-15) package, with 90V working stand-off voltage (VWM), 100–122V breakdown voltage (VBR @ 1mA), and 160V maximum clamping voltage (VC) at 3.2A peak pulse current. It delivers fast response (<1.0ps), low leakage (<1μA @ 90V), and AEC-Q101 qualification for automotive-grade surge protection.

For engineers reviewing the SA90 datasheet, SA90 pinout, SA90 application, or SA90 equivalent, this page provides verified electrical parameters, clamping behavior under 10/1000μs transients, thermal derating curves, polarity marking guidance, and direct alternatives for ESD/inductive load protection in lighting, power supply inputs, and automotive ECUs.

Technical Context

The SA90 operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its 100–122V breakdown range at 1mA test current. Its clamping action limits transient energy to ≤160V at 3.2A (10/1000μs waveform), enabling robust protection of downstream 90V-rated circuits without forward conduction during normal operation.

Designed for single-polarity DC rail protection, it features a cathode band marking, pure tin-plated leads compliant with J-STD-002, and UL 94V-0 molding compound. Junction temperature range spans –55°C to +175°C, supporting under-hood automotive deployment with no derating required up to 75°C ambient.

Key Specifications

Pinout & Package

DO-204AC (DO-15) package with axial leads: cathode indicated by a band on one end; anode is unmarked lead. Leads are pure tin-plated, solderable per J-STD-002, and meet JESD 201 Class 2 whisker resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ90A and 1.5SMC90A, the SA90 offers lower leakage current and AEC-Q101 qualification out-of-box, making it optimal for cost-sensitive, high-reliability automotive through-hole designs where thermal margin and long-term stability are critical.

Availability

SA90 is available at Aetrix Electronics and suitable for automotive lighting systems, industrial power supply inputs, ESD-prone sensor interfaces, and inductive load switching protection requiring stable component supply and full traceability.

Supply support for SA90 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 device manufacturer headquartered in Hsinchu, Taiwan, serving global automotive, industrial, and consumer markets since 1979.

The SA Series TVS diodes are engineered specifically for high-energy transient suppression in harsh environments, emphasizing AEC-Q101 reliability, tight VBR tolerances, and consistent clamping performance across temperature.

FAQ

What is the maximum clamping voltage of the SA90 under standard 10/1000μs surge conditions?

The SA90 exhibits a maximum clamping voltage (VC) of 160 V when subjected to a 10/1000μs waveform at its rated peak pulse current of 3.2 A. This value is measured per ANSI/IEEE C62.35 and ensures protected circuitry remains within safe operating limits during standardized surge events. The SA90 datasheet confirms this VC rating at TA = 25°C with specified test conditions.

Is the SA90 suitable for automotive applications, and what qualification does it hold?

Yes, the SA90 is explicitly qualified to AEC-Q101 for automotive use, as confirmed in the SA Series documentation. It meets stress test requirements for temperature cycling, humidity, mechanical shock, and surge endurance-making it appropriate for under-hood and cabin applications such as lighting modules, body control units, and sensor interfaces. The SA90's +175°C junction rating further supports this qualification.

How does the SA90 differ from the SA90A variant?

The SA90A has a tighter breakdown voltage range (100–111 V vs. SA90's 100–122 V), lower clamping voltage (146 V vs. 160 V at 3.5 A), and identical 90 V VWM. Both share DO-204AC packaging and AEC-Q101 qualification, but SA90A offers improved consistency for precision-clamping applications where tighter VBR tolerance is critical. The SA90 remains preferred where cost and broader surge margin are prioritized.

What is the reverse leakage current specification for the SA90 at its working stand-off voltage?

The SA90 specifies reverse leakage current (IR) of less than 1 μA when biased at its full working stand-off voltage of 90 V. This ultra-low leakage minimizes power loss in always-on systems and avoids false triggering in high-impedance sensing nodes. The value is measured at TA = 25°C and remains well below 5 μA even at elevated temperatures per TSC's derating curves.

Does the SA90 have polarity marking, and how is it identified on the device?

Yes, the SA90 uses a cathode band marking on the DO-204AC (DO-15) package to indicate polarity-consistent with standard diode convention. The banded end is the cathode and must be connected toward the positive side of the protected circuit. This marking is visible on the molded epoxy body and aligns with the "Cathode band for uni-directional products only" note in the SA Series package outline diagram.