Taiwan Semiconductor Corporation SS320ALH

Overview

SS320ALH from Taiwan Semiconductor is a 3A, 200V Schottky barrier surface-mount rectifier in Thin SMA package, optimized for high-efficiency DC/DC conversion with low forward voltage (0.85V at 3A, 25°C) and high surge capability (70A IFSM). It serves as a primary output rectifier in automotive-grade SMPS and on-board power supplies.

For engineers reviewing the SS320ALH datasheet, SS320ALH pinout, SS320ALH application, or SS320ALH equivalent, key selection criteria include its 200V VRRM rating, AEC-Q101 qualification, thermal resistance (RθJA = 81°C/W), junction temperature limit (150°C), and cathode-band polarity marking-critical for layout validation and automotive reliability assurance.

Technical Context

The SS320ALH uses a single-die Schottky structure with platinum-silicide or similar barrier metallization to achieve low VF while maintaining 200V reverse blocking. Its thin SMA package enables compact board placement and automated assembly, with moisture sensitivity level 1 per J-STD-020.

Thermal performance is defined for mounting on a 5mm × 5mm copper pad: RθJL = 19°C/W and RθJC = 18°C/W confirm efficient heat transfer from junction to lead or case, supporting sustained 3A operation at elevated ambient temperatures up to 125°C.

Key Specifications

Pinout & Package

Package: Thin SMA - Surface-mount, single-ended, cathode-band marked device with matte tin-plated leads (J-STD-002 compliant), UL 94V-0 molding compound, and 0.028g mass.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Schottky rectifier applications.

Compared with SS320ALH, the SB320-E3/54 offers lower thermal resistance and marginally lower VF but shares identical voltage/current ratings and AEC-Q101 status; the VS-3EWH02-F provides equivalent voltage rating and current handling in a non-automotive-qualified TO-277 variant with inferior thermal performance.

Availability

SS320ALH is available at Aetrix Electronics and suitable for automotive on-board DC/DC converters, industrial LED driver power stages, and telecom AC-DC adapters requiring stable component supply, long-term lifecycle support, and AEC-Q101-compliant sourcing.

Supply support for SS320ALH 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in power rectifiers, TVS devices, and MOSFETs for industrial and automotive markets.

The SS320ALH belongs to TSC's SS3xALH Schottky rectifier family, engineered for high-reliability, high-efficiency secondary-side rectification in automotive and industrial power supplies where AEC-Q101 compliance and thermal robustness are mandatory.

FAQ

What is the maximum junction temperature rating for SS320ALH?

The SS320ALH has a maximum junction temperature (TJ max) of 150°C, verified per absolute maximum ratings in the official datasheet. This rating enables reliable operation in under-hood automotive environments and enclosed industrial enclosures. The SS320ALH maintains specified electrical performance up to this limit when thermal design adheres to the RθJA = 81°C/W condition on a 5mm × 5mm Cu pad. Derating curves confirm usable current capacity down to 1.5A at 125°C ambient.

Is SS320ALH AEC-Q101 qualified and what does that cover?

Yes, SS320ALH is explicitly AEC-Q101 qualified per the manufacturer's documentation. This qualification covers stress tests including high-temperature operating life (HTOL), temperature cycling (TC), and high-temperature reverse bias (HTRB), validating suitability for automotive power electronics. The SS320ALH's qualification applies specifically to the Thin SMA package variant and supports use in body control modules, infotainment systems, and ADAS power rails-not medical or safety-critical applications.

What is the forward voltage of SS320ALH at 3A and 125°C?

The SS320ALH exhibits a typical forward voltage of 0.71 V at 3A and 125°C, with a maximum of 0.80 V under those conditions. This value is measured per pulse test (PW = 0.3ms) and reflects real-world performance in thermally stressed SMPS output stages. The SS320ALH's VF decreases with rising temperature-a characteristic of Schottky diodes-making it more efficient at elevated operating points than silicon PN rectifiers.

Does SS320ALH have a cathode band marking and how is polarity identified?

Yes, SS320ALH uses a visible cathode band to indicate polarity, consistent with JEDEC-standard Thin SMA marking. The band marks the cathode terminal, which must be connected to the higher-potential node in forward conduction (e.g., output rail). This marking is laser-etched or molded into the epoxy body and remains legible after reflow soldering. The SS320ALH's polarity identification aligns with industry-standard layout practices and eliminates ambiguity during automated optical inspection (AOI).

What is the junction-to-ambient thermal resistance (RθJA) of SS320ALH and how is it measured?

The SS320ALH has a junction-to-ambient thermal resistance (RθJA) of 81°C/W, measured on a standard test board with a 5mm × 5mm copper pad per JESD51-2. This value assumes no additional heatsinking and defines the worst-case thermal gradient under natural convection. The SS320ALH's RθJA directly impacts maximum allowable power dissipation: at 3A and 0.85V VF, Pdiss ≈ 2.55W yields ~207°C rise-confirming the necessity of proper PCB copper area. RθJA is validated for the Thin SMA package only.