Taiwan Semiconductor Corporation TUAS8D

Overview

TUAS8D from Taiwan Semiconductor is a single-die, 8A, 200V standard surface-mount rectifier in TO-277A (SMPC4.6U) package, featuring 0.96V forward voltage at 8A/25°C, 230A surge rating, and 4°C/W junction-to-lead thermal resistance - deployed in DC-DC converters for high-efficiency power conversion.

For engineers reviewing the TUAS8D datasheet, TUAS8D pinout, TUAS8D application, or TUAS8D equivalent, key selection criteria include repetitive peak reverse voltage (200V), forward current rating (8A), thermal resistance (R_θJL = 4°C/W), wettable flank geometry, and J-STD-020 Level 1 moisture sensitivity.

Technical Context

This device operates as a unidirectional silicon rectifier with cathode-band polarity marking, optimized for automated SMT placement and reflow soldering on PCBs with 16mm × 16mm copper pads. Its low VF (0.96V max @ 8A/25°C) and high IFSM (230A @ 8.3ms) support robust transient handling in switching-mode power supplies.

The TO-277A (SMPC4.6U) package delivers enhanced thermal performance via low R_θJL (4°C/W) and R_θJC (8°C/W), while matte tin-plated leads meet J-STD-002 solderability and JESD201 Class 1 whisker resistance requirements.

Key Specifications

Pinout & Package

TO-277A (SMPC4.6U) surface-mount package with two terminals: anode and cathode, polarity indicated by molded cathode band. Matte tin-plated leads support automated placement and comply with J-STD-002 solderability and JESD201 Class 1 whisker resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-8EWH02FN-M3 and MUR820G, the TUAS8D offers superior manufacturability via wettable flank and J-STD-020 Level 1 compliance, while maintaining identical V_RRM/I_F ratings - making it optimal for high-volume SMT production of cost-sensitive industrial power supplies.

Availability

TUAS8D is available at Aetrix Electronics and suitable for DC-DC converters, switching inverters, and general-purpose rectification requiring stable component supply, consistent parametric performance, and long-term industrial lifecycle support.

Supply support for TUAS8D 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 industrial, computing, and consumer markets since 1979.

The TUAS8D belongs to TSC's standard rectifier product line, engineered for high-reliability surface-mount power conversion in cost-sensitive, high-volume applications where thermal robustness and process compatibility are essential.

FAQ

What is the maximum repetitive peak reverse voltage for TUAS8D?

The TUAS8D has a maximum repetitive peak reverse voltage (V_RRM) of 200 V, verified per its absolute maximum ratings table. This rating defines the highest reverse-biased voltage the device can block repeatedly without breakdown. It is critical for selecting appropriate safety margins in rectifier circuits - for example, ensuring ≥2× derating against peak AC line voltages in input-stage applications. The TUAS8D datasheet confirms this value applies specifically to the TUAS8D variant, not the broader TUAS8x family.

Does TUAS8D support automated optical inspection (AOI) after reflow?

Yes, the TUAS8D features wettable flank geometry on its TO-277A (SMPC4.6U) package, enabling reliable side-view AOI of solder fillets. This design meets IPC-A-610 Class 2/3 requirements for solder joint quality verification in high-mix SMT lines. The matte tin-plated leads and controlled flank profile ensure consistent reflectivity and contrast - a key advantage over non-wettable alternatives. TUAS8D's wettable flank is explicitly documented in its mechanical data section.

What is the forward voltage drop of TUAS8D at full rated current?

The TUAS8D exhibits a maximum forward voltage (V_F) of 0.96 V at 8 A and 25°C junction temperature, per its electrical specifications table. At elevated temperature (125°C), V_F drops to 0.87 V max under the same current. This low conduction loss directly reduces power dissipation - for example, yielding ≤7.7 W at 8 A - supporting thermally constrained layouts. All V_F values for TUAS8D are measured using 0.3 ms pulse testing.

Is TUAS8D RoHS and halogen-free compliant?

Yes, the TUAS8D is RoHS compliant and halogen-free per IEC 61249-2-21, as confirmed in its features list and ordering documentation. Its molding compound meets UL 94V-0 flammability rating, and terminals are matte tin plated without lead, bromine, chlorine, fluorine, or iodine above threshold limits. These compliance attributes are certified for the TUAS8D variant and apply to all units shipped under version C2109.

What is the thermal resistance from junction to lead for TUAS8D?

The TUAS8D has a typical junction-to-lead thermal resistance (R_θJL) of 4°C/W, measured with the device mounted on a 16 mm × 16 mm copper pad test board. This parameter quantifies heat transfer efficiency from die to PCB copper via the leads - critical for predicting temperature rise under conduction-cooled conditions. R_θJL is lower than R_θJA (38°C/W), confirming that lead-based thermal path dominates over ambient convection in typical layouts. This value is specified exclusively for TUAS8D in the thermal performance table.