Taiwan Semiconductor Corporation SMA4S60AH

Overview

SMA4S60AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode rated for 60 V working stand-off voltage, 67.1–74.1 V breakdown voltage at 1 mA, and 400 W peak pulse power (10/1000 µs). It features SOD-128 package, AEC-Q101 qualification, and 175 °C maximum junction temperature-designed for overvoltage protection in automotive BLDC motor drives and battery management systems.

For engineers reviewing the SMA4S60AH datasheet, SMA4S60AH pinout, SMA4S60AH application, or SMA4S60AH equivalent, key selection criteria include clamping voltage (97.4 V @ 4.1 A), low leakage (<1 µA @ 60 V), thermal resistance (R_θJL = 20 °C/W), and unidirectional polarity with glass-passivated junction.

Technical Context

The SMA4S60AH operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its specified V_BR range (67.1–74.1 V). Its 97.4 V clamping voltage at 4.1 A IPPM ensures predictable overvoltage limiting during transients such as load dump or inductive switching.

Thermally, it delivers R_θJL = 20 °C/W and R_θJA = 62 °C/W on a 5 mm × 5 mm copper pad, enabling reliable operation up to 175 °C junction temperature. The device meets JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity.

Key Specifications

Pinout & Package

Package: SOD-128 - Surface-mount plastic package with gull-wing leads, UL 94V-0 rated molding compound, matte tin-plated terminals, and cathode band marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ60A and SMBJ60A, the SMA4S60AH offers superior thermal resistance (R_θJL = 20 °C/W), AEC-Q101 validation, and optimized SOD-128 footprint-making it preferred for space-constrained, high-reliability automotive and industrial power rails.

Availability

SMA4S60AH is available at Aetrix Electronics and suitable for automotive BLDC motor control, battery management systems, and LED lighting applications requiring stable component supply, AEC-Q101 compliance, and repeatable surge immunity performance.

Supply support for SMA4S60AH 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 automotive qualification capabilities.

The SMA4SxxAH series was developed specifically for AEC-Q101-compliant transient suppression in 12–60 V automotive and industrial power systems, emphasizing thermal robustness, low leakage, and tight V_BR tolerance.

FAQ

What is the clamping voltage of the SMA4S60AH under peak pulse conditions?

The SMA4S60AH exhibits a maximum clamping voltage (V_C) of 97.4 V when subjected to a 10/1000 µs surge current of 4.1 A. This value is measured per JEDEC standards and defines the upper voltage limit imposed on protected circuits during transient events. The SMA4S60AH maintains this clamping performance across its full operating temperature range, ensuring consistent protection behavior in automotive under-hood environments.

Is the SMA4S60AH suitable for bidirectional transient suppression?

No, the SMA4S60AH is a unidirectional TVS diode, designed to protect against positive transients only when connected with cathode to the protected line and anode to ground. It does not provide symmetrical clamping for negative-going surges. For bidirectional protection, a separate design using two unidirectional devices or a dedicated bidirectional TVS like SMA4S60AY would be required. The SMA4S60AH's polarity is marked by a cathode band on the SOD-128 package.

Does the SMA4S60AH meet automotive reliability standards?

Yes, the SMA4S60AH is AEC-Q101 qualified, having passed stress tests including high-temperature reverse bias (HTRB), temperature cycling, and mechanical shock per automotive component requirements. It also complies with JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity-enabling lead-free reflow without pre-baking. These qualifications confirm the SMA4S60AH's suitability for under-hood and safety-critical vehicle subsystems.

What is the thermal resistance from junction to lead (R_θJL) for the SMA4S60AH?

The SMA4S60AH has a typical junction-to-lead thermal resistance (R_θJL) of 20 °C/W when mounted on a standard 5 mm × 5 mm copper pad PCB. This low value enables efficient heat transfer from the silicon die to the PCB copper, supporting sustained power dissipation and improving reliability in high-temperature environments. The SMA4S60AH's R_θJL is significantly lower than comparable SOD-123 devices, making it advantageous in thermally constrained layouts.

How does the breakdown voltage tolerance of the SMA4S60AH impact circuit design?

The SMA4S60AH specifies a breakdown voltage (V_BR) range of 67.1 V to 74.1 V at 1 mA test current, reflecting manufacturing spread and temperature coefficient (≤0.095%/°C). Designers must ensure that the protected circuit's absolute maximum voltage rating exceeds the upper bound (74.1 V) to avoid unintended conduction. This tolerance also informs margining decisions for clamping headroom relative to system V_MAX, especially in 60 V nominal battery applications where V_BR variation affects trip point consistency.