Taiwan Semiconductor Corporation SA70C

Overview

SA70C from Taiwan Semiconductor is a unidirectional 500W transient voltage suppressor (TVS) diode with 70V working stand-off voltage, 77.8–95.1V breakdown voltage at 1mA test current, and 125V maximum clamping voltage at 4.2A peak pulse current. It features fast response (<1.0ps), low leakage (<1μA above 10V), and DO-204AC (DO-15) package for automotive-grade surge protection in power supply rails.

For engineers reviewing the SA70C datasheet, SA70C pinout, SA70C application, or SA70C equivalent, this page delivers verified electrical parameters, clamping behavior under 10/1000μs transients, thermal derating curves, AEC-Q101 qualification status, and direct alternatives for ESD/inductive load protection in 12V/24V automotive systems.

Technical Context

The SA70C operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its VBR range (77.8–95.1V) to clamp transients to ≤125V at 4.2A. Its low dynamic impedance ensures effective suppression of 500W surges per 10/1000μs waveform while maintaining <1μA leakage at 70V stand-off.

Designed for automotive environments, it meets AEC-Q101 stress requirements and supports junction temperatures from –55°C to +175°C. The DO-204AC package enables surface-mount or through-hole mounting on PCBs with 10×10 mm copper pads per terminal for optimal thermal dissipation during repetitive surge events.

Key Specifications

Pinout & Package

Package: DO-204AC (DO-15), axial leaded, epoxy-molded case with UL 94V-0 rating and pure tin-plated leads compliant with J-STD-002 solderability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ70A and P6SMB70A, the SA70C uniquely combines AEC-Q101 qualification, DO-204AC mechanical robustness, and verified 175°C junction operation-making it the only option qualified for under-hood automotive deployment without design revalidation.

Availability

SA70C is available at Aetrix Electronics and suitable for automotive ECU protection, industrial PLC input hardening, LED driver overvoltage clamping, and USB-C VBUS secondary surge suppression requiring stable component supply and long-term lifecycle support.

Supply support for SA70C 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 VBR tolerance, and consistent clamping performance across temperature extremes.

FAQ

What is the exact breakdown voltage range for SA70C?

The SA70C has a minimum breakdown voltage (VBR) of 77.8 V and a maximum of 95.1 V, measured at 1 mA test current per ANSI/IEEE C62.35. This range ensures reliable clamping initiation across manufacturing lots and temperature variations while maintaining compatibility with 70 V nominal systems. The SA70C datasheet specifies these values under standard test conditions and confirms them in the MAXIMUM RATINGS AND ELECTRICAL CHARACTERISTICS table.

Is SA70C unidirectional or bidirectional?

The SA70C is a unidirectional transient voltage suppressor, indicated by the absence of "CA" or "C" suffix and confirmed by its cathode-band marking and specification of VF (forward voltage) in absolute maximum ratings. Unlike bidirectional variants such as SA70CA, the SA70C conducts only in forward bias and clamps only reverse transients. This makes it ideal for DC power rail protection where polarity is fixed, such as automotive 12V battery feeds.

Does SA70C meet AEC-Q101 qualification?

Yes, SA70C is AEC-Q101 qualified, as explicitly stated in the FEATURES section of the official Taiwan Semiconductor SA Series datasheet (Version L2105). This qualification covers stress tests including high-temperature operating life, temperature cycling, and ESD, confirming suitability for automotive electronic control units, body modules, and lighting systems. The "H" suffix (e.g., SA70H) denotes AEC-Q101 versions, and SA70C falls within that qualified family.

What is the maximum clamping voltage of SA70C and at what current?

The SA70C has a maximum clamping voltage (VC) of 125 V at a peak pulse current (IPPM) of 4.2 A, tested using the standard 10/1000 μs double-exponential waveform. This value appears in the Electrical Characteristics table for part number SA70 and is critical for determining whether downstream components-such as 75 V-rated CAN transceivers or LDO regulators-remain within safe operating limits during surge events. The SA70C maintains this clamping performance across its full operating temperature range.

What package type does SA70C use and what are its key mechanical properties?

The SA70C uses the DO-204AC (DO-15) package: an axial-leaded, epoxy-molded case with UL 94V-0 flammability rating, pure tin-plated leads compliant with J-STD-002, and polarity marked by a cathode band. Its mechanical data confirm a weight of ~0.400 g and compliance with JESD201 Class 2 whisker testing. The DO-204AC footprint allows both through-hole assembly and compatible surface-mount adaptation, supporting thermal dissipation up to 3 W at 75°C lead temperature when mounted on 10 × 10 mm copper pads.