Taiwan Semiconductor Corporation SA170

Overview

SA170 from Taiwan Semiconductor is a unidirectional 170V working stand-off voltage Transient Voltage Suppressor (TVS) diode in DO-204AC (DO-15) package, rated for 500W peak pulse power at 10/1000μs, with 189–231V breakdown voltage (V_BR), 304A peak pulse current (I_PPM), and 230V clamping voltage (V_C) - deployed for automotive ESD and inductive load transient protection.

For engineers reviewing the SA170 datasheet, SA170 pinout, SA170 application, or SA170 equivalent, this page delivers verified electrical parameters, mechanical package details, real-world use cases in lighting and automotive subsystems, and validated alternative parts with documented differences in clamping performance and leakage behavior.

Technical Context

The SA170 operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its V_BR range (189–231V at 1mA test current), clamping transients to ≤230V at 304A. Its low dynamic impedance enables effective suppression of fast-rising EFT and lightning-induced surges.

Designed for single-polarity DC systems, it features <1μA reverse leakage at 170V (V_WM), a maximum junction temperature of +175°C, and AEC-Q101 qualification when ordered with "H" suffix - confirming suitability for under-hood automotive environments.

Key Specifications

Pinout & Package

Package: DO-204AC (DO-15), axial leaded, epoxy-molded case with UL 94V-0 rating; cathode indicated by band marking; leads pure tin plated, J-STD-002 solderable; weight ≈0.400g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ170A and 1.5KE170A, the SA170 offers superior clamping (230V vs. ≥274V), lower leakage (<1μA vs. ~5μA), and DO-15 compatibility for legacy automotive PCBs - making it optimal for space-constrained, unidirectional 12V/24V rail protection.

Availability

SA170 is available at Aetrix Electronics and suitable for automotive electronics, industrial solenoid control, LED lighting systems, and LIN/CAN subsystems requiring stable component supply with consistent DO-15 form factor and AEC-Q101 traceability.

Supply support for SA170 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 - headquartered in Hsinchu, Taiwan, with global distribution and AEC-Q101 certification capability.

The SA Series was developed specifically for automotive and industrial transient suppression, emphasizing low clamping voltage, tight V_BR tolerance, and robust surge survivability in DO-15 packaging - targeting cost-sensitive, high-reliability 12V/24V system designs.

FAQ

What is the breakdown voltage range of the SA170?

The SA170 has a specified breakdown voltage (V_BR) range of 189 V to 231 V at a test current (I_T) of 1 mA, measured per ANSI/IEEE C62.35. This range ensures reliable avalanche initiation across process and temperature variations while maintaining design margin above its 170 V working stand-off voltage - critical for consistent protection in automotive 12V/24V systems where SA170 is commonly deployed.

Is the SA170 suitable for bidirectional transient protection?

No - the SA170 is a unidirectional TVS diode, intended for DC circuits with defined polarity. For bidirectional protection (e.g., AC lines or differential buses), the SA170A variant or SA170CA should be used. The SA170's cathode band marking and asymmetric I-V curve mean it conducts only in reverse bias; using it in bidirectional configurations risks failure during positive transients, unlike purpose-built bipolar devices such as the SA170A which exhibits matched V_BR in both directions.

What is the maximum clamping voltage of the SA170 during a surge event?

The SA170 clamps to a maximum of 230 V when subjected to its rated peak pulse current of 304 A under the standard 10/1000 μs waveform. This clamping voltage is guaranteed across temperature and lifetime, ensuring protected downstream components - such as 200 V-rated MOSFETs or DC-DC controllers - remain within their absolute maximum ratings. The low V_C directly results from SA170's optimized silicon geometry and low dynamic impedance, distinguishing it from higher-clamp alternatives like 1.5KE170A (274 V).

Does the SA170 meet automotive reliability standards?

Yes - the SA170H variant is explicitly qualified to AEC-Q101 for stress testing including HTGB, H3TRB, TC, and ESD. While the base SA170 part number is not automatically qualified, TSC's SA Series manufacturing flow supports AEC-Q101 compliance when ordered with the "H" suffix. Engineers specifying SA170 for automotive applications must select SA170H to ensure qualification documentation, lot traceability, and failure rate data required for PPAP submissions - the standard SA170 lacks this formal validation.

What package type and mounting requirements apply to the SA170?

The SA170 uses the DO-204AC (DO-15) axial-leaded package with pure tin-plated leads compliant with J-STD-002 solderability. It requires mounting on 10 × 10 mm copper pads per terminal for rated 3 W steady-state dissipation at T_L = 75°C. The cathode is marked by a band; correct orientation is essential for unidirectional operation. Its 0.400 g mass and UL 94V-0 molding compound support automated insertion and reflow-compatible assembly in automotive PCBs where SA170 is routinely applied.