Taiwan Semiconductor Corporation TUAS8MH

Overview

TUAS8MH from Taiwan Semiconductor is a 8A, 1000V standard surface-mount rectifier diode in TO-277A (SMPC4.6U) package, AEC-Q101 qualified, with 230A surge rating (8.3ms), 0.96V max forward voltage at 8A/25°C, and 54pF junction capacitance. It serves as primary AC/DC or DC/DC rectification element in high-reliability automotive power supplies.

For engineers reviewing the TUAS8MH datasheet, TUAS8MH pinout, TUAS8MH application, or TUAS8MH equivalent, key selection criteria include peak reverse voltage (1000V), thermal resistance (R_θJL = 4°C/W), wettable flank terminals for solder joint inspection, AEC-Q101 qualification, and TO-277A mechanical compatibility with automated SMT lines.

Technical Context

The TUAS8MH is a single-die standard recovery rectifier optimized for high-voltage, medium-current switching applications. Its 1000V V_RRM, 230A I_FSM (8.3ms), and 150°C T_J(max) support robust operation in transient-prone automotive environments.

Thermal design is enabled by low R_θJL (4°C/W) and R_θJC (8°C/W), verified on 16mm × 16mm Cu pad PCBs. Junction capacitance is specified at 54pF (1MHz, V_R = 4.0V), consistent across TUAS8KH–TUAS8MH variants.

Key Specifications

Pinout & Package

TO-277A (SMPC4.6U) surface-mount package with wettable flank leads, matte tin plating, polarity indicated by cathode band, and 0.104g mass. Designed for reflow soldering per J-STD-002 and JEDEC moisture level 1 handling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage rectifier applications.

Compared with VS-8EWH10 and MUR8100CT, the TUAS8MH uniquely combines AEC-Q101 qualification, wettable flank leads, and 4°C/W R_θJL in a compact TO-277A package-enabling automotive-grade reliability, automated optical inspection, and superior thermal performance in space-constrained SMT designs.

Availability

TUAS8MH is available at Aetrix Electronics and suitable for automotive DC/DC converters, LED headlamp power supplies, and industrial AC/DC front-ends requiring stable component supply, long-term lifecycle assurance, and AEC-Q101-compliant sourcing.

Supply support for TUAS8MH 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 automotive, industrial, and consumer markets since 1979.

The TUAS8MH belongs to TSC's AEC-Q101-qualified surface-mount rectifier family, engineered specifically for high-reliability automotive power conversion where voltage margin, thermal efficiency, and automated manufacturability are critical.

FAQ

What is the maximum junction temperature rating for TUAS8MH?

The TUAS8MH has a maximum junction temperature (T_J(max)) of +150°C, validated per absolute maximum ratings table. This rating applies under continuous operation with proper PCB thermal design-specifically using a 16mm × 16mm Cu pad test board per datasheet thermal characterization. Operation beyond this limit risks permanent degradation of the silicon die and bond wires.

Is TUAS8MH pin-compatible with other parts in the TUAS8xH series?

Yes, all TUAS8xH variants-including TUAS8DH, TUAS8GH, TUAS8JH, TUAS8KH, and TUAS8MH-share identical TO-277A (SMPC4.6U) package dimensions, leadframe geometry, and pinout (anode/cathode). The only difference is rated V_RRM; thus, TUAS8MH can replace lower-voltage variants in the same footprint when higher reverse voltage margin is needed.

Does TUAS8MH require special PCB layout considerations?

Yes. To achieve the published R_θJL = 4°C/W and R_θJA = 38°C/W, the TUAS8MH must be mounted on a PCB with ≥16mm × 16mm copper pads per terminal, connected via multiple thermal vias to internal ground/power planes. The datasheet specifies this as the test condition; reduced copper area increases thermal resistance and limits safe operating current.

What does the marking code "AS8M" indicate on TUAS8MH?

The marking code "AS8M" laser-etched on the TUAS8MH case identifies it as the 1000V variant within the TUAS8xH family. Per the ordering information table, "M" corresponds to V_RRM = 1000V, distinguishing it from "D" (200V), "G" (400V), "J" (600V), and "K" (800V) versions-all sharing the same TO-277A package and electrical construction.

How does the wettable flank feature benefit TUAS8MH in production?

The wettable flank on TUAS8MH exposes solderable metal along the side of each lead, enabling automated optical inspection (AOI) of solder fillet quality after reflow-without requiring X-ray. This reduces process validation time, improves first-pass yield in automotive electronics manufacturing, and eliminates hidden voids that could cause long-term thermal or mechanical failure in field-deployed units.