Taiwan Semiconductor Corporation SA75CAH

Overview

SA75CAH from Taiwan Semiconductor is a bidirectional 75V transient voltage suppressor (TVS) diode in DO-204AC (DO-15) package, rated for 500W peak pulse power at 10/1000μs, with 83.3–102V breakdown voltage (V_BR), 134V clamping voltage (V_C) at 3.9A peak pulse current, and <1μA reverse leakage at 75V. It protects automotive-grade power and signal lines against ESD, EFT, and inductive switching transients.

For engineers reviewing the SA75CAH datasheet, SA75CAH pinout, SA75CAH application, or SA75CAH equivalent, key selection criteria include its AEC-Q101 qualification, bidirectional clamping symmetry, 175°C junction temperature rating, low 134V clamping under 3.9A surge, and DO-15 mechanical compatibility with legacy PCB footprints.

Technical Context

The SA75CAH operates as a bidirectional avalanche diode, symmetrically clamping voltage transients in both polarities without polarity dependence. Its V_BR range (83.3–102V) ensures reliable triggering above 75V working stand-off while maintaining tight tolerance (±11.3%). The device uses silicon planar junction technology optimized for fast response (<5ns) and low dynamic impedance.

Designed for automotive environments, it meets AEC-Q101 stress requirements including temperature cycling, humidity bias, and mechanical shock. Its 175°C maximum junction temperature and -55°C to +175°C operating range support under-hood and powertrain applications where thermal derating is critical.

Key Specifications

Pinout & Package

SA75CAH is housed in a DO-204AC (DO-15) axial-leaded package with cathode band marking omitted due to bidirectional functionality. Leads are pure tin-plated, solderable per J-STD-002, and meet JESD 201 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 SMBJ75CA and 1.5KE75CA, SA75CAH uniquely combines AEC-Q101 qualification, DO-15 through-hole compatibility, and precise 500W/134V clamping-making it the only drop-in solution for automotive ECU upgrades requiring zero layout change and full qualification traceability.

Availability

SA75CAH is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, LED lighting drivers, and CAN/LIN bus protection requiring stable component supply across extended temperature and qualification-critical programs.

Supply support for SA75CAH 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, with ISO/TS 16949 certification and global distribution.

The SA Series was developed specifically for automotive-grade transient suppression, emphasizing AEC-Q101 compliance, tight parametric tolerances, and robust thermal performance in under-hood environments.

FAQ

What does the "H" suffix in SA75CAH signify?

The "H" suffix in SA75CAH indicates full AEC-Q101 qualification per Rev D requirements, covering stress tests including high-temperature operating life, temperature cycling, and unbiased highly accelerated stress testing. SA75CAH is not merely compliant-it is certified and documented by Taiwan Semiconductor for automotive use, unlike standard SA75CA variants.

Is SA75CAH unidirectional or bidirectional, and how is polarity marked?

SA75CAH is a bidirectional TVS diode, meaning it provides symmetrical clamping in both forward and reverse directions. No cathode band or polarity marking is present on the DO-204AC package-both leads are functionally identical, enabling flexible placement across AC-coupled or differential signal lines without orientation concerns.

What is the maximum clamping voltage of SA75CAH under standardized surge conditions?

The maximum clamping voltage of SA75CAH is 134 V, measured at 3.9 A peak pulse current using the 10/1000 μs double-exponential waveform per ANSI/IEEE C62.35. This value is guaranteed across the full operating temperature range (-55°C to +175°C) and represents the upper limit of voltage seen by protected circuitry during worst-case transients.

Can SA75CAH replace SA75A in an existing design?

SA75CAH can replace SA75A only if AEC-Q101 qualification is required and the application demands bidirectional protection. SA75A is unidirectional with cathode marking and lacks automotive qualification. Electrical parameters (V_WM, V_BR, V_C) are nearly identical, but SA75CAH's bidirectional behavior and qualification make it unsuitable as a drop-in replacement unless the original design intentionally used bidirectional clamping.

What is the steady-state power dissipation rating for SA75CAH at elevated temperatures?

SA75CAH has a steady-state power dissipation (P_D) of 3 W when mounted on 10 × 10 mm copper pads per lead at 75°C lead temperature (T_L). Derating follows the curve in Figure 2 of the datasheet: at 125°C T_L, P_D drops to ~1.5 W. This rating applies only to continuous DC or low-frequency reverse bias-not to transient suppression duty cycles.