Taiwan Semiconductor Corporation SA9.0

Overview

SA9.0 from Taiwan Semiconductor is a unidirectional 500W transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power rails and signal lines. It features a 9.0V working stand-off voltage (VWM), 10.0–12.2V breakdown voltage (VBR) at 1mA test current, 16.9V maximum clamping voltage (VC) at 31A peak pulse current, and DO-204AC (DO-15) axial package - used in automotive lighting control modules to absorb load-dump transients.

For engineers reviewing the SA9.0 datasheet, SA9.0 pinout, SA9.0 application, or SA9.0 equivalent, key selection criteria include clamping performance under 10/1000μs surge, low leakage (<5μA @ 9.0V), AEC-Q101 qualification eligibility (via SA9.0H variant), and thermal robustness up to +175°C junction temperature.

Technical Context

The SA9.0 operates as a silicon avalanche diode with fast response (<1.0ps from 0V to VBR), low dynamic impedance, and stable breakdown characteristics across -55°C to +175°C. Its unidirectional polarity enables asymmetric clamping on positive-going transients only, with cathode band marking per DO-204AC mechanical standard.

It complies with ANSI/IEEE C62.35 for transient suppression, supports 70A non-repetitive forward surge (IFSM), and delivers 500W peak pulse power (PPK) at TA = 25°C - derated linearly above ambient per Fig.2 in the datasheet.

Key Specifications

Pinout & Package

Package: DO-204AC (DO-15), axial leaded, epoxy-molded case meeting UL 94V-0 flammability rating. Cathode indicated by band; leads are pure tin-plated and solderable per J-STD-002.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ9.0A and 1.5KE9.1A, the SA9.0 offers optimal balance of compact DO-15 packaging, automotive-grade thermal capability (+175°C), and precise 9.0V standoff - making it ideal for cost-sensitive, space-limited 12V automotive modules where bidirectional clamping is unnecessary.

Availability

SA9.0 is available at Aetrix Electronics and suitable for automotive lighting control, industrial PLC I/O protection, and body control module designs requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SA9.0 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 qualification capabilities.

The SA Series was developed specifically for automotive and industrial transient suppression, emphasizing high surge robustness, low clamping voltage, and extended temperature operation in harsh environments.

FAQ

What is the polarity configuration of the SA9.0?

The SA9.0 is a unidirectional TVS diode with cathode band marking per DO-204AC mechanical standard. It conducts only during positive transients applied to the cathode relative to anode, making it suitable for DC rail protection where reverse voltage is not expected. This polarity must be observed during PCB layout to ensure proper clamping function - incorrect orientation renders the SA9.0 ineffective against overvoltage events.

Does the SA9.0 meet AEC-Q101 qualification?

The base SA9.0 part is not AEC-Q101 qualified; however, the SA9.0H variant - identified by the "H" suffix in the ordering code - is fully AEC-Q101 qualified per version L2105 documentation. Engineers requiring automotive-grade reliability should specify SA9.0H for under-hood applications, while SA9.0 remains suitable for industrial or consumer systems where qualification is not mandated.

How does the SA9.0 compare to the SA9.0A variant?

The SA9.0A differs from SA9.0 in tighter VBR tolerance (10.0–11.1V vs. 10.0–12.2V) and lower clamping voltage (15.4V vs. 16.9V at 34A), achieved via process optimization. Both share identical VWM (9.0V), IR (<5μA), and package (DO-15). SA9.0A is preferred where stricter voltage control is needed, such as in precision 9V regulator input stages, while SA9.0 offers broader design margin for general-purpose clamping.

What is the maximum allowable surge repetition rate for the SA9.0?

The SA9.0 is rated for non-repetitive 10/1000μs surges per Fig.3; its datasheet specifies no defined repetition limit but mandates derating of peak power above TA = 25°C per Fig.2. For repetitive surges, thermal accumulation must be evaluated using junction-to-ambient thermal resistance (R_θJA) and duty cycle - typical practice limits repetition to ≤1 pulse/minute unless board-level thermal design confirms safe average power dissipation.

Can the SA9.0 be used in bidirectional signal line protection?

No - the SA9.0 is strictly unidirectional and unsuitable for bidirectional signal lines like RS-485 or USB D+/D−. For such applications, a bidirectional variant (e.g., SA9.0CA, if offered) or a symmetric TVS array is required. Using SA9.0 on bidirectional lines risks forward conduction during negative transients, potentially damaging upstream drivers or violating signal integrity requirements.