Taiwan Semiconductor Corporation S2KALH

Overview

S2KALH from Taiwan Semiconductor is a 2 A, 800 V standard surface-mount silicon rectifier diode in a Thin SMA package, featuring glass-passivated junction, AEC-Q101 qualification, and 50 A surge capability (8.3 ms), used for freewheeling and snubber functions in automotive DC/DC converters.

For engineers reviewing the S2KALH datasheet, S2KALH pinout, S2KALH application, or S2KALH equivalent, key selection criteria include peak reverse voltage (800 V), forward voltage at 2 A (0.98 V max @ 25°C), thermal resistance (R_θJL = 14 °C/W), junction temperature range (–55 to +150 °C), and moisture sensitivity level (MSL 1).

Technical Context

The S2KALH is a single-die, unidirectional standard recovery rectifier optimized for high-reliability automotive and industrial power conversion. Its glass-passivated junction ensures stable reverse leakage (<1 µA @ 25°C, <33 µA @ 125°C) and robustness against humidity and thermal cycling.

Designed for surface-mount assembly on PCBs with 5 mm × 5 mm copper pads, it delivers R_θJA = 74 °C/W (free air) and R_θJC = 20 °C/W, supporting continuous 2 A conduction with derating above 75°C ambient per the forward current derating curve.

Key Specifications

Pinout & Package

Package: Thin SMA (Surface Mount Axial), low-profile, matte tin-plated leads, polarity indicated by cathode band, MSL Level 1, UL 94V-0 molding compound, weight ≈ 0.029 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STTH2R08 and ES2J, the S2KALH uniquely combines AEC-Q101 qualification, Thin SMA surface-mount compatibility, and 14 °C/W R_θJL-enabling compact, thermally efficient, and automotive-compliant rectification without layout or qualification compromises.

Availability

S2KALH is available at Aetrix Electronics and suitable for automotive DC/DC converters, industrial snubber circuits, and power supply freewheeling applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for S2KALH 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, serving global automotive, industrial, and consumer markets since 1979.

The S2KALH belongs to TSC's AEC-Q101-qualified Thin SMA rectifier family, engineered specifically for high-reliability surface-mount power conversion in automotive underhood and industrial control environments.

FAQ

What is the maximum junction temperature rating for S2KALH?

The S2KALH has a maximum junction temperature (T_J) rating of +150 °C, verified per AEC-Q101 thermal stress testing. This allows reliable operation in under-hood automotive environments and high-ambient industrial settings. The device must be mounted on a PCB with adequate copper area to maintain T_J ≤ 150 °C under full 2 A load. Derating begins above 75 °C ambient, as shown in Figure 1 of the S2KALH datasheet.

Is S2KALH suitable for automotive applications?

Yes, the S2KALH is AEC-Q101 qualified and explicitly listed for automotive applications in its official documentation. It meets requirements for temperature cycling, high-temperature reverse bias (HTRB), and high-temperature gate bias (HTGB). Its glass-passivated junction, MSL Level 1 rating, and –55 to +150 °C operating range make it appropriate for engine control units, lighting drivers, and DC/DC converters in vehicles.

What does the marking code 'S2KAH' indicate on the S2KALH device body?

The marking code 'S2KAH' on the S2KALH device body identifies it as the 800 V variant within the S2xALH family. Per the ordering table, 'K' corresponds to V_RRM = 800 V, and 'AH' denotes the Thin SMA package and halogen-free construction. The full orderable part number remains S2KALH; 'S2KAH' is the top-side laser marking used for visual identification during assembly and inspection.

How does the thermal performance of S2KALH compare between junction-to-lead and junction-to-ambient?

The S2KALH has R_θJL = 14 °C/W and R_θJA = 74 °C/W (measured on a 5 mm × 5 mm Cu pad test board). This 5.3× difference confirms that effective thermal design must prioritize conduction from the lead frame into PCB copper-not reliance on ambient convection. For 2 A operation, limiting ΔT_JL to ≤30 °C requires ≥2.14 W of power dissipation capacity via the leads, making copper pour and thermal vias essential.

What is the reverse leakage current specification for S2KALH at elevated temperature?

The S2KALH specifies reverse leakage current (I_R) ≤ 33 µA at rated V_R and T_J = 125 °C, per the Electrical Specifications table. At T_J = 25 °C, I_R is ≤ 1 µA. This low, well-characterized leakage supports stable blocking in high-impedance snubber networks and ensures minimal standby power loss in automotive always-on circuits.