Taiwan Semiconductor Corporation S1MLS

Overview

S1MLS from Taiwan Semiconductor is a 1000V, 1.2A standard surface-mount silicon rectifier diode in SOD-123HE package, designed for high-voltage DC/DC conversion and switching-mode power supplies where compact size and surge robustness are critical. It features 50A peak forward surge current (IFSM), 175°C maximum junction temperature, and low 1.3V forward voltage at 1.2A.

For engineers reviewing the S1MLS datasheet, S1MLS pinout, S1MLS application, or S1MLS equivalent, key selection criteria include repetitive peak reverse voltage (1000V), thermal resistance (RθJA = 86°C/W), moisture sensitivity level (MSL 1), RoHS/halogen-free compliance, and compatibility with automated placement on PCBs with 5mm × 5mm Cu pads.

Technical Context

The S1MLS operates as a single-die, unidirectional standard rectifier with cathode-band polarity indication and no integrated protection or control logic. Its electrical behavior is defined by fixed VRRM (1000V), IF (1.2A continuous), and IR ≤ 5 µA at 25°C - all specified under JESD22-A110 and J-STD-020 conditions.

Thermal performance is characterized using a standardized 5mm × 5mm copper pad test board: RθJL = 46°C/W and RθJC = 50°C/W confirm efficient heat transfer from junction to lead and case, supporting stable operation up to TJ = 175°C in high-density power layouts.

Key Specifications

Pinout & Package

Package: SOD-123HE - surface-mount, single-anode/single-cathode plastic case with matte tin-plated leads, UL 94V-0 molding compound, and cathode band polarity marking. Weight: 0.022 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MUR110S and VS-1N5819HM3/85A, the S1MLS uniquely balances 1000V capability, 1.2A current, SOD-123HE compactness, and MSL 1 manufacturability - making it optimal for cost-sensitive, space-constrained, high-input-voltage power supplies where both surge resilience and assembly yield matter.

Availability

S1MLS is available at Aetrix Electronics and suitable for AC/DC adapters, industrial DC/DC converters, and LED driver power stages requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for S1MLS 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 rectifiers, TVS diodes, MOSFETs, and power ICs since 1979.

The S1DLS–S1MLS series belongs to TSC's standard rectifier product line, engineered specifically for high-voltage, surface-mount power conversion applications demanding reliability, thermal robustness, and automated assembly compatibility.

FAQ

What is the maximum repetitive peak reverse voltage (VRRM) for the S1MLS?

The S1MLS has a VRRM of 1000 V, verified per Taiwan Semiconductor's H2103 datasheet revision. This rating defines the highest instantaneous reverse voltage the device can block repeatedly without breakdown. Engineers must ensure system-level transient voltages - including ringing and reflected spikes - remain below this limit to prevent catastrophic failure. The S1MLS achieves this rating while maintaining a compact SOD-123HE footprint and MSL 1 handling.

Does the S1MLS support automated pick-and-place assembly?

Yes, the S1MLS is explicitly designed for automated placement, as confirmed in its official features list. Its SOD-123HE package, matte tin-plated leads, and MSL 1 classification (per J-STD-020) eliminate pre-baking and ensure reliable solder joint formation in standard reflow profiles. The 0.022g weight and standardized outline further enhance placement accuracy and yield in high-speed SMT lines - a key advantage over larger or non-MSL-1 rectifiers like the TO-277-based MUR110S.

What is the forward voltage (VF) specification for the S1MLS at rated current?

The S1MLS has a maximum forward voltage of 1.3 V at IF = 1.2 A and TJ = 25°C, per the H2103 datasheet's electrical specifications table. This value is measured under pulsed conditions (PW = 0.3 ms) to minimize self-heating. At elevated junction temperatures or higher currents, VF increases slightly but remains within predictable bounds - enabling accurate conduction loss calculation (e.g., ~1.56 W at full load) for thermal design of the S1MLS in real-world power stages.

Can the S1MLS be used in automotive body control module (BCM) power supplies?

Yes, the S1MLS is suitable for BCM auxiliary power supplies, provided the application operates within its 1000V VRRM and 1.2A IF ratings. Its halogen-free construction complies with IEC 61249-2-21 and RoHS, satisfying automotive material disclosure requirements. However, it is not AEC-Q101 qualified - so while functionally appropriate for non-safety-critical 12V input rectification, it should not be used in airbag, braking, or ADAS subsystems without additional qualification testing per the S1MLS datasheet and customer-specific reliability protocols.

What is the thermal resistance from junction to ambient (RθJA) for the S1MLS?

The S1MLS has a junction-to-ambient thermal resistance of 86°C/W, measured on a standard 5 mm × 5 mm copper pad test board per JEDEC JESD51-2. This value reflects realistic PCB-level dissipation - not idealized heatsink conditions. When designing with the S1MLS, engineers should use this RθJA to calculate expected junction temperature rise (ΔTJ = Pd × 86°C/W) and verify that TJ remains ≤175°C under worst-case load and ambient conditions, especially in enclosed or convection-limited environments.