Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Discrete Semiconductor Products > Diodes > Rectifiers > Single Diodes

Taiwan Semiconductor Corporation SS12LS

Name: SS12LS
Brand: Taiwan Semiconductor Corporation
SKU: SS12LS
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: SS12LS

Manufacturer:: Taiwan Semiconductor Corporation

Category:: Single Diodes

Package:: SOD-123H

Datasheet:: SS12LS.pdf

Description:: 1A, 20V, SCHOTTKY RECTIFIER

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:2,760

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

SS12LS from Taiwan Semiconductor is a 1A, 20V Schottky barrier surface-mount rectifier in SOD-123HE package, featuring low forward voltage (0.45 V at 1.0 A, 25°C), high surge current capability (30 A, 8.3 ms), and junction temperature rating up to +125°C. It serves as a high-efficiency output rectifier in compact DC/DC converters and AC/DC adapters.

For engineers reviewing the SS12LS datasheet, SS12LS pinout, SS12LS application, or SS12LS equivalent, key selection criteria include its 20 V reverse voltage rating, 0.45 V forward drop at rated current, SOD-123HE footprint compatibility, thermal resistance (R_θJA = 70°C/W), and moisture sensitivity level 1 compliance.

Technical Context

The SS12LS is a single-die Schottky rectifier optimized for low-loss switching applications. Its 20 V V_RRM, 1 A continuous forward current, and 30 A non-repetitive surge rating support reliable operation in high-frequency SMPS topologies where conduction loss minimization is critical.

Thermal performance is defined by R_θJC = 25°C/W and R_θJA = 70°C/W, with a maximum junction temperature of +125°C. The device uses matte tin-plated leads, meets JESD201 Class 2 whisker resistance, and carries a cathode band polarity indicator.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	20 V - Maximum repetitive reverse voltage; sets safe operating limit in buck or flyback secondary-side rectification
I_F	1 A - Continuous forward current rating; defines steady-state power delivery capacity
I_FSM	30 A - Peak surge current (8.3 ms half-sine); withstands startup/inrush transients without failure
V_F	0.45 V @ 1.0 A, 25°C - Low conduction loss improves efficiency and reduces thermal load in space-constrained designs
T_J max	+125°C - Maximum junction temperature; enables operation in ambient temperatures up to ~85°C with proper PCB copper area
C_J	80 pF @ 1 MHz, 4 V - Junction capacitance impacts high-frequency switching noise and EMI behavior
R_θJA	70°C/W - Thermal resistance from junction to ambient; guides heatsinking and layout decisions for thermal management

Pinout & Package

SOD-123HE is a compact surface-mount plastic package with 2 terminals, profile height < 0.85 mm, UL 94V-0 molding compound, and cathode polarity indicated by a band.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry point	Connected to lower-potential node (e.g., transformer secondary center-tap or switch node in synchronous rectifier configuration)
Cathode	Forward current exit point	Connected to output rail; marked by visible band; determines unidirectional conduction path

Key Features

Feature	Design Value
Low forward voltage	0.45 V at 1.0 A enables >90% efficiency in 5–12 V output DC/DC stages with minimal thermal derating
High surge current rating	30 A peak supports robustness against line transients and capacitor charging surges without bond-wire fusing
Ultra-low profile package	SOD-123HE height < 0.85 mm allows integration into ultra-thin power modules and portable adapter PCBs
Moisture sensitivity level 1	No bake requirement before reflow; compatible with standard J-STD-020 assembly processes without special handling
Halogen-free construction	Complies with IEC 61249-2-21; satisfies environmental requirements for consumer and industrial end equipment

Applications

Switching Mode Power Supply (SMPS)	AC/DC Adapters
Use Scenario: Secondary-side rectification in 5–24 V output flyback or forward converters delivering up to 12 W. IC Role / Device Role / Timing Role: Unidirectional current steering diode replacing conventional PN rectifiers to reduce conduction loss. Use Value: 0.45 V forward drop cuts power dissipation by ~40% vs. comparable 1 A silicon diodes, lowering thermal stress on PCB.	Use Scenario: Output rectification in wall-mounted USB-C PD adapters with tight height constraints (<12 mm). IC Role / Device Role / Timing Role: Surface-mount Schottky rectifier mounted directly on primary-side PCB layer for compact layout. Use Value: SOD-123HE's 0.85 mm profile enables mechanical stacking with ICs and magnetics without interference.
DC/DC Converters	Industrial Control Power Rails
Use Scenario: Point-of-load (POL) rectification in isolated 3.3 V/5 V buck-derived supplies for microcontrollers and sensors. IC Role / Device Role / Timing Role: High-frequency rectifier synchronized with PWM switching (100 kHz–1 MHz) to minimize reverse recovery loss. Use Value: Absence of minority-carrier storage eliminates reverse recovery charge (Q_rr ≈ 0), reducing switching node ringing and EMI.	Use Scenario: Auxiliary bias supply rectification in PLC I/O modules requiring long-term reliability under 60°C ambient. IC Role / Device Role / Timing Role: Input-stage rectifier feeding linear regulators or LDOs powering analog signal chains. Use Value: +125°C T_J max and JESD201 Class 2 whisker resistance ensure stable operation over 10+ year field life.

Switching Mode Power Supply (SMPS)

AC/DC Adapters

Use Scenario: Secondary-side rectification in 5–24 V output flyback or forward converters delivering up to 12 W.

IC Role / Device Role / Timing Role: Unidirectional current steering diode replacing conventional PN rectifiers to reduce conduction loss.

Use Value: 0.45 V forward drop cuts power dissipation by ~40% vs. comparable 1 A silicon diodes, lowering thermal stress on PCB.

Use Scenario: Output rectification in wall-mounted USB-C PD adapters with tight height constraints (<12 mm).

IC Role / Device Role / Timing Role: Surface-mount Schottky rectifier mounted directly on primary-side PCB layer for compact layout.

Use Value: SOD-123HE's 0.85 mm profile enables mechanical stacking with ICs and magnetics without interference.

DC/DC Converters

Industrial Control Power Rails

Use Scenario: Point-of-load (POL) rectification in isolated 3.3 V/5 V buck-derived supplies for microcontrollers and sensors.

IC Role / Device Role / Timing Role: High-frequency rectifier synchronized with PWM switching (100 kHz–1 MHz) to minimize reverse recovery loss.

Use Value: Absence of minority-carrier storage eliminates reverse recovery charge (Q_rr ≈ 0), reducing switching node ringing and EMI.

Use Scenario: Auxiliary bias supply rectification in PLC I/O modules requiring long-term reliability under 60°C ambient.

IC Role / Device Role / Timing Role: Input-stage rectifier feeding linear regulators or LDOs powering analog signal chains.

Use Value: +125°C T_J max and JESD201 Class 2 whisker resistance ensure stable operation over 10+ year field life.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ON Semiconductor SS12H	V_RRM = 20 V, I_F = 1 A, V_F = 0.52 V @ 1 A, SOD-123 package (not HE variant)	Slightly higher forward voltage increases conduction loss by ~15%; same thermal resistance but no HE-profile optimization	Preferred when legacy SOD-123 footprint is fixed and height margin > 0.95 mm exists
Vishay VS-1EQH02HM3	V_RRM = 20 V, I_F = 1 A, V_F = 0.43 V @ 1 A, SOD-123FL package, MSL level 1	Lower V_F improves efficiency marginally; SOD-123FL has identical outline but different leadframe geometry affecting solder joint reliability	Selected for highest efficiency priority where board-level vibration resistance is not critical

Compared with SS12H and VS-1EQH02HM3, the SS12LS delivers a balanced trade-off of ultra-low profile (SOD-123HE), industry-leading MSL 1 handling, and competitive forward voltage-making it optimal for space- and reliability-constrained adapter and POL designs.

Availability

SS12LS is available at Aetrix Electronics and suitable for switching mode power supplies, AC/DC adapters, and DC/DC converters requiring stable component supply, consistent parametric performance, and long-term manufacturability.

Supply support for SS12LS 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 semiconductor manufacturer specializing in discrete power devices, including rectifiers, MOSFETs, and TVS diodes, with global distribution and AEC-Q200 qualified product lines.

The SS12LS belongs to TSC's SSxLS Schottky rectifier family, engineered specifically for high-efficiency, low-profile secondary-side rectification in consumer and industrial power conversion systems.

FAQ

What is the maximum junction temperature rating for the SS12LS?

The SS12LS has a maximum junction temperature (T_J) rating of +125°C. This value is specified in the Absolute Maximum Ratings table and applies under continuous operation with appropriate PCB thermal relief. Exceeding this temperature may cause irreversible degradation of the Schottky junction. Derating curves in the datasheet show allowable forward current reduction above 25°C ambient, and the SS12LS must be used within this thermal envelope to ensure reliability over its operational lifetime.

Does the SS12LS have a specified reverse recovery time (t_rr)?

No, the SS12LS does not specify reverse recovery time because it is a Schottky barrier diode with majority-carrier conduction. Unlike PN junction diodes, Schottky devices exhibit negligible stored charge and effectively zero reverse recovery time. This characteristic eliminates switching losses associated with t_rr and reduces EMI generation during high-frequency operation-key advantages confirmed in the SS12LS electrical specifications and application curves.

Is the SS12LS RoHS and halogen-free compliant?

Yes, the SS12LS is RoHS compliant and halogen-free per IEC 61249-2-21. These compliance statements are explicitly listed in the FEATURES section of the official Taiwan Semiconductor documentation. The device uses matte tin-plated leads and UL 94V-0 molding compound, satisfying environmental requirements for consumer electronics, industrial controls, and energy-efficient power supplies.

What is the moisture sensitivity level (MSL) of the SS12LS and what does it mean for assembly?

The SS12LS has a moisture sensitivity level (MSL) of Level 1 per J-STD-020. This means the device can be stored indefinitely at ≤30°C/60% RH without baking prior to surface-mount reflow. No floor life limitation applies, and standard reflow profiles may be used without preconditioning-reducing manufacturing complexity and cost for high-volume adapter and SMPS production.

Can the SS12LS replace a standard PN rectifier like 1N4001 in an existing design?

The SS12LS can replace a 1N4001 only in low-voltage, high-frequency applications where its 20 V V_RRM and Schottky characteristics are acceptable. While both are 1 A diodes, the 1N4001 has 50 V rating and significant reverse recovery, whereas the SS12LS offers lower V_F but lower voltage rating and no reverse recovery. Direct substitution requires verifying that reverse voltage stress never exceeds 20 V and that system timing benefits from zero Q_rr. For legacy 50 V designs, SS12LS is not suitable.

SS12LS Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Series:: -

Package/Case:: SOD-123H

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Schottky

Voltage - DC Reverse (Vr) (Max):: 20 V

Current - Average Rectified (Io):: 1A

Voltage - Forward (Vf) (Max) @ If:: 450 mV @ 1 A

Speed:: Fast Recovery =< 500ns, > 200mA (Io)

Reverse Recovery Time (trr):: -

Current - Reverse Leakage @ Vr:: 400 µA @ 20 V

Capacitance @ Vr, F:: 80pF @ 4V, 1MHz

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOD-123HE

Operating Temperature - Junction:: -55°C ~ 125°C

SS12LS FAQ

1.How can I place an order for SS12LS through Aetrix?

Please submit a Request for Quotation (RFQ) for SS12LS on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for SS12LS reliable?

The price and inventory of SS12LS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SS12LS is usually 5 days.

3.What payment methods are accepted for SS12LS?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SS12LS transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SS12LS?

SS12LS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SS12LS order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for SS12LS?

For technical support, including SS12LS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SS12LS requirements.

6.How does Aetrix verify that SS12LS is sourced from the original manufacturer or authorized distributors?

All SS12LS products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SS12LS meets industry standards.

7.What is the process for return or replacement of SS12LS?

All SS12LS units undergo pre-shipment inspection (PSI). If there is an issue with SS12LS, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The SS12LS part is unused and in its original packaging.

Return procedure for SS12LS:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…