Taiwan Semiconductor Corporation SA70CA

Overview

SA70CA 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 low leakage (<1μA @ 70V), fast response (<1.0ps), and AEC-Q101 qualification for automotive-grade surge protection in power supply rails and interface lines.

For engineers reviewing the SA70CA datasheet, SA70CA pinout, SA70CA application, or SA70CA equivalent, this page delivers verified electrical parameters, DO-204AC package details, bidirectional-capable variant context, clamping performance under 10/1000μs transients, and direct alternatives for ESD and inductive switching protection in automotive and industrial systems.

Technical Context

The SA70CA is a unidirectional TVS diode designed to shunt high-energy transients away from sensitive downstream circuitry by entering avalanche breakdown when reverse voltage exceeds VBR (77.8–95.1V). Its 500W peak pulse power rating is specified at the standard 10/1000μs waveform, with clamping voltage tightly controlled at ≤125V up to 4.2A IPPM.

It operates across –55°C to +175°C junction temperature range, exhibits <1μA reverse leakage at rated VWM (70V), and uses a silicon planar junction structure housed in a DO-204AC (DO-15) package with pure tin-plated leads compliant with J-STD-002 solderability and JESD201 Class 2 whisker resistance.

Key Specifications

Pinout & Package

SA70CA is a two-terminal unidirectional TVS diode in DO-204AC (DO-15) package. Cathode is marked by a band on the body; anode is unmarked lead. Leads are pure tin-plated, solderable per J-STD-002, and meet JESD201 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 SMBJ70A and P6SMB70A, the SA70CA provides superior leakage performance (<1μA vs. ≥5μA), proven DO-204AC mechanical robustness for vibration-prone environments, and AEC-Q101 validation out-of-box-making it the preferred choice for automotive power entry and industrial through-hole surge protection.

Availability

SA70CA is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor interface hardening, LED driver input safeguarding, and communication port surge suppression requiring stable component supply across extended temperature and lifecycle requirements.

Supply support for SA70CA 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, rectifiers, and MOSFETs for automotive, industrial, and consumer markets.

The SA Series was developed specifically for high-reliability transient suppression in harsh environments, emphasizing AEC-Q101 compliance, tight parametric distribution, and robust DO-204AC packaging for under-hood and factory-floor deployment.

FAQ

What is the clamping voltage of SA70CA at its rated peak pulse current?

The SA70CA has a maximum clamping voltage (VC) of 125 V at 4.2 A peak pulse current (IPPM), measured under the standard 10/1000μs waveform. This value defines the upper voltage limit imposed on protected circuitry during a full-rated surge event and is confirmed in TSC's SA Series datasheet Version L2105, Table on Page 4. The SA70CA maintains this clamping performance across its full operating temperature range.

Is SA70CA unidirectional or bidirectional, and how is polarity identified?

The SA70CA is a unidirectional TVS diode, meaning it clamps only in reverse bias and conducts forward current like a standard diode. Polarity is marked by a cathode band on the DO-204AC (DO-15) package body; the banded end connects to the protected line (e.g., 70V rail), while the unmarked lead connects to ground or return. Bidirectional variants in the SA family use the "CA" suffix but differ in internal construction and symmetry.

Does SA70CA meet AEC-Q101 qualification, and what does that cover?

Yes, SA70CA is AEC-Q101 qualified, as explicitly stated in the "FEATURES" section of the official SA Series datasheet (Version L2105). This qualification covers stress tests including high-temperature operating life (HTOL), temperature cycling, mechanical shock, and ESD (HBM ≥8kV, CDM ≥1kV), validating suitability for automotive electronic control units, body modules, and powertrain subsystems.

What is the maximum junction temperature and thermal derating behavior of SA70CA?

The SA70CA has a maximum junction temperature (TJ) of +175°C and follows standard derating curves per Figure 2 in the datasheet: peak pulse power decreases linearly from 500W at 25°C ambient to zero at ~175°C case temperature. Derating is based on thermal resistance from junction-to-case (RθJC), which is optimized by the DO-204AC package's copper lead frame and 0.400g mass-enabling sustained operation in under-hood environments.

How does SA70CA compare to SA70 in terms of electrical performance and application use?

The SA70CA differs from SA70 in breakdown voltage tightness: SA70CA specifies VBR = 77.8–86.0 V (tighter 10% window), while SA70 spans 77.8–95.1 V. Both share identical VWM (70 V), VC (125 V), and PPK (500 W). SA70CA is preferred where precise clamping onset is critical-such as in regulated 70V auxiliary supplies-whereas SA70 suits general-purpose protection with wider tolerance acceptance.