Taiwan Semiconductor Corporation S1AB

Overview

S1AB from Taiwan Semiconductor is a 1 A, 50 V repetitive peak reverse voltage (V_RRM) standard surface-mount silicon rectifier in DO-214AA (SMB) package, featuring low forward voltage drop (1.1 V at 1 A), 30 A surge capability, and glass-passivated junction for reliability in power conversion stages of AC/DC adapters and SMPS.

For engineers reviewing the S1AB datasheet, S1AB pinout, S1AB application, or S1AB equivalent, key selection criteria include its 50 V V_RRM, 1 A continuous forward current rating, 30 A I_FSM, thermal resistance of 30 °C/W, and SMB package compatibility with automated placement and J-STD-002 solderability requirements.

Technical Context

The S1AB is a single-die, unidirectional standard rectifier optimized for low-loss DC output stage rectification in low-to-moderate voltage switching power supplies. Its glass-passivated junction ensures stable reverse leakage (<5 µA at 25 °C, <50 µA at 125 °C) and robustness against moisture and mechanical stress.

Designed for operation up to 150 °C junction temperature, the device uses a DO-214AA (SMB) thermally efficient package with matte tin-plated leads, UL 94V-0 molding compound, and polarity indicated by cathode band - enabling reliable integration into compact, high-density PCB layouts without derating penalties below 125 °C ambient.

Key Specifications

Pinout & Package

Package: DO-214AA (SMB), surface-mount, single-anode/single-cathode configuration with cathode band marking. Matte tin-plated leads, UL 94V-0 compliant epoxy body, 0.090 g mass.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M1AB and VS-1A50, the S1AB offers identical voltage/current ratings and SMB footprint while delivering the highest specified I_FSM at 25 °C - making it optimal for cost-sensitive, high-volume adapter and lighting designs requiring robust surge headroom without layout change.

Availability

S1AB is available at Aetrix Electronics and suitable for AC/DC adapters, LED lighting drivers, and switching mode power supplies requiring stable component supply, consistent parametric performance, and full RoHS/halogen-free compliance.

Supply support for S1AB 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 power, automotive, and industrial markets since 1979.

The S1AB belongs to TSC's S1x series of standard rectifiers - engineered for high-volume, cost-optimized AC/DC and DC/DC power conversion where reliability, manufacturability, and thermal performance are prioritized over ultra-low V_F or fast recovery.

FAQ

What is the maximum junction temperature rating for the S1AB?

The S1AB has a maximum junction temperature (T_J) rating of +150 °C, with a storage temperature range of –55 °C to +150 °C. This allows operation in thermally demanding environments such as enclosed LED drivers or industrial SMPS without external heatsinking, provided the lead temperature remains within limits and thermal design accounts for R_θJL = 30 °C/W. The S1AB must be operated within this limit to ensure long-term reliability and parameter stability.

Is the S1AB RoHS and halogen-free compliant?

Yes, the S1AB is RoHS compliant and halogen-free in accordance with IEC 61249-2-21. Its molding compound meets UL 94V-0 flammability rating, and terminals are matte tin plated and solderable per J-STD-002. These compliance attributes are verified per TSC's I2102 specification revision and are documented in the official S1AB datasheet - critical for export-controlled and environmentally regulated end products using the S1AB.

What does the "S1AB" marking code indicate on the device body?

The "S1AB" marking code printed on the S1AB device body identifies it as the 50 V variant within the S1AB–S1MB family. Per TSC's ordering nomenclature, the "x" in S1xB corresponds to voltage grade: A = 50 V, B = 100 V, D = 200 V, etc. This marking is visible as a laser-etched or molded code adjacent to the cathode band and confirms the exact V_RRM = 50 V rating of the S1AB unit in hand.

Can the S1AB replace a 1N4001 in existing designs?

The S1AB is not a direct functional replacement for the through-hole 1N4001 due to package and thermal differences: the S1AB is DO-214AA (SMB) surface-mount with R_θJL = 30 °C/W, while the 1N4001 is DO-41 with higher thermal resistance. Though both share 1 A / 50 V ratings, the S1AB requires PCB pad redesign and reflow validation. For drop-in replacement, consider TSC's through-hole S1A (DO-41) instead of the S1AB.

What is the reverse leakage current specification for the S1AB at elevated temperature?

The S1AB specifies reverse leakage current (I_R) ≤ 5 µA at 25 °C and ≤ 50 µA at 125 °C, measured at rated V_R with 30 ms pulse width. This behavior is confirmed in the Electrical Specifications table of the I2102 datasheet. The increase with temperature reflects intrinsic silicon properties and remains within safe operational limits for SMPS and adapter applications where ambient temperatures rarely exceed 85 °C - ensuring stable S1AB performance across its full rated junction range.