Taiwan Semiconductor Corporation SA70AH

Overview

SA70AH from Taiwan Semiconductor is an AEC-Q101-qualified unidirectional transient voltage suppressor (TVS) diode in DO-204AC (DO-15) package, rated for 500W peak pulse power at 10/1000μs, 70V working stand-off voltage (VWM), and clamping voltage of 125V at 4.2A peak pulse current. It delivers fast response (<1.0ps), low leakage (<1μA @ 70V), and operates from –55°C to +175°C - used for automotive ESD and load-dump protection in power supply inputs.

For engineers reviewing the SA70AH datasheet, SA70AH pinout, SA70AH application, or SA70AH equivalent, this page provides verified electrical parameters, DO-15 terminal polarity mapping, automotive-grade reliability data, clamping performance under IEC 61000-4-5 surge conditions, and direct alternatives with documented VWM/VC/IPPM trade-offs.

Technical Context

The SA70AH is a unidirectional silicon avalanche diode designed to clamp transient overvoltages by entering avalanche breakdown when reverse voltage exceeds its 77.8–95.1V breakdown range (VBR @ 1mA). Its low dynamic impedance ensures stable clamping at 125V (VC) under 4.2A 10/1000μs pulses, while maintaining <1μA reverse leakage at 70V (VWM).

It meets AEC-Q101 stress requirements for temperature cycling, humidity, and mechanical shock, and features pure tin-plated leads compliant with J-STD-002 solderability and JESD201 Class 2 whisker resistance. Polarity is marked by cathode band; no internal series resistance or integrated capacitance tuning is present.

Key Specifications

Pinout & Package

SA70AH uses a two-terminal DO-204AC (DO-15) axial package with polarity indicated by a cathode band. Leads are pure tin-plated, solderable per J-STD-002, and meet UL 94V-0 flammability rating. Weight is 0.400g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ70A and 1.5KE70A, the SA70AH uniquely combines AEC-Q101 qualification, DO-15 form factor, and sub-1μA leakage at 70V - making it optimal for space-constrained, automotive-grade 12V/24V input protection where low standby current and reliability validation are mandatory.

Availability

SA70AH is available at Aetrix Electronics and suitable for automotive ECU designs, industrial sensor interfaces, LED driver inputs, and power supply ESD protection requiring stable component supply across multi-year production cycles.

Supply support for SA70AH 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 headquartered in Hsinchu, Taiwan, specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for automotive and industrial markets.

The SA Series was developed specifically for AEC-Q101-compliant transient suppression in automotive power networks and industrial equipment, emphasizing robust clamping, low leakage, and high-temperature operation in compact DO-15 packaging.

FAQ

What is the breakdown voltage range of the SA70AH?

The SA70AH 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 consistent avalanche initiation across production lots while accommodating process variation - critical for predictable clamping behavior in automotive 12V systems where nominal battery voltage can swing from 9V to 16V.

Is the SA70AH unidirectional or bidirectional?

The SA70AH is a unidirectional TVS diode, as confirmed by its part number suffix "H" (AEC-Q101 variant of SA70) and explicit marking requirement: cathode band on the DO-204AC package. It conducts only during reverse overvoltage events and must be oriented with cathode toward the protected line - unlike bidirectional variants (e.g., SA70A) which suppress surges in both polarities.

Does the SA70AH meet AEC-Q101 requirements?

Yes, the SA70AH is explicitly AEC-Q101 qualified, as stated in the SA Series datasheet Version L2105 and confirmed in the ordering code "SA70AH" where "H" denotes AEC-Q101 compliance. Testing includes temperature cycling, high-temperature operating life, unbiased highly accelerated stress test (uHAST), and mechanical shock - validating suitability for automotive under-hood applications.

What is the clamping voltage of the SA70AH under surge conditions?

The SA70AH clamps to a maximum of 125 V when subjected to its rated 4.2 A peak pulse current (IPPM) using the 10/1000μs waveform. This value is measured per IEC 61000-4-5 and defines the upper voltage limit imposed on protected circuitry during surge events - directly enabling compatibility with 36V-input DC-DC controllers and safeguarding against insulation breakdown in adjacent components.

What package type does the SA70AH use, and how is polarity identified?

The SA70AH uses the DO-204AC (DO-15) axial leaded package with a cathode band marking the banded end. This matches industry-standard through-hole assembly processes and enables manual or automated placement. The band identifies the cathode terminal, which must connect to the line being protected - correct orientation is essential for unidirectional clamping functionality in the SA70AH.