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

Diodes Incorporated SD103A-T

Name: SD103A-T
Brand: Diodes Incorporated
SKU: SD103A-T
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SD103A-T

Manufacturer:: Diodes Incorporated

Category:: Single Diodes

Package:: DO-204AH, DO-35, Axial

Datasheet:: SD103A-T.pdf

Description:: DIODE SCHOTTKY 40V 350MA DO35

Quantity:: RFQ Add To RFQ list

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Inventory:9,763

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Product details

Overview

SD103A-T from Diodes Incorporated is a glass-passivated Schottky barrier diode in DO-35 package, rated for 40 V peak repetitive reverse voltage, 350 mA forward continuous current, and 10 ns reverse recovery time. It features low forward voltage drop (0.60 V at 200 mA), guard ring construction for transient protection, and RoHS-compliant Sn96.5Ag3.5 terminations. Used in high-efficiency DC-DC converter output rectification and low-voltage power supply freewheeling paths.

For engineers reviewing the SD103A-T datasheet, SD103A-T pinout, SD103A-T application, or SD103A-T equivalent, key selection criteria include its 40 V V_RRM, 10 ns t_rr, 50 pF C_T at 0 V, thermal resistance of 300 °C/W, and DO-35 mechanical compatibility with legacy through-hole layouts.

Technical Context

This Schottky diode operates via majority-carrier conduction, eliminating minority-carrier storage delay and enabling fast switching with minimal reverse recovery loss. Its guard ring structure enhances ruggedness against voltage transients and improves reliability under repetitive surge conditions.

The DO-35 glass package provides hermetic sealing and stable junction temperature behavior up to 125 °C, while the Sn96.5Ag3.5 lead finish ensures solderability per MIL-STD-202 Method 208 and compliance with J-STD-020C Level 1 moisture sensitivity.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	40 V - Maximum repetitive reverse blocking capability without breakdown
I_F	350 mA - Continuous forward current rating at 25 °C ambient
t_rr	10 ns - Reverse recovery time enabling >10 MHz switching in SMPS designs
V_FM	0.60 V @ 200 mA - Low conduction loss improving efficiency in low-voltage outputs
C_T	50 pF @ 0 V, 1 MHz - Junction capacitance affecting high-frequency noise coupling and EMI
R_θJA	300 °C/W - Thermal resistance limiting power dissipation in still-air PCB mounting

Pinout & Package

Package: DO-35 glass axial-leaded package with cathode band marking; 0.13 g mass; dimensions A = 25.4 mm max length, B = 4.0 mm max body diameter, C = 0.6 mm max lead diameter, D = 2.0 mm max lead spacing.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry point	Connected to lower-potential node (e.g., switch node in buck converter)
Cathode	Forward current exit / reverse blocking terminal	Marked with band; connected to output rail or ground return path

Key Features

Feature	Design Value
Guard ring construction	Enhances transient voltage immunity and prevents edge breakdown during surge events
Low V_FM (0.37 V typ @ 20 mA)	Reduces conduction loss in battery-powered and energy-sensitive circuits
10 ns reverse recovery time	Enables high-frequency operation without tail current losses or cross-conduction risk
RoHS-compliant Sn96.5Ag3.5 finish	Ensures reliable solder joint formation and compatibility with lead-free reflow profiles

Applications

DC-DC Converter Output Rectification

Low-Voltage Freewheeling Path

Use Scenario: Synchronous buck converter output stage where low V_F minimizes conduction loss at 3.3 V/5 V rails.

IC Role / Device Role / Timing Role: Freewheeling diode conducting during high-side FET off-time; defines minimum on-time limit via reverse recovery behavior.

Use Value: 10 ns t_rr avoids shoot-through in synchronous designs and reduces EMI from reverse recovery spikes.

Use Scenario: Linear regulator input-to-output bypass path handling inrush and load dump transients.

IC Role / Device Role / Timing Role: Clamping diode providing low-impedance discharge path during regulator shutdown or dropout.

Use Value: Guard ring structure withstands 15 A non-repetitive surge (8.3 ms half-sine), protecting downstream LDOs.

USB Port Protection

Signal Line Clamp in Low-Power Sensors

Use Scenario: VBUS line reverse polarity and overvoltage protection in USB 2.0 host ports.

IC Role / Device Role / Timing Role: Series-blocking diode preventing backfeed from peripheral into host when VBUS is absent.

Use Value: 40 V V_RRM accommodates automotive USB applications with load dump transients up to 36 V.

Use Scenario: I²C or UART signal line ESD clamping in battery-operated environmental sensors.

IC Role / Device Role / Timing Role: Low-capacitance shunt clamp limiting voltage excursions to <0.7 V above rail.

Use Value: 50 pF C_T avoids signal integrity degradation on 400 kHz I²C buses with 10 kΩ pull-ups.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N5817-T	V_RRM = 20 V, t_rr = 50 ns, DO-41 package	Limited to ≤12 V systems; slower recovery increases switching loss above 500 kHz	Select only if 20 V rating suffices and board layout allows larger DO-41 footprint
SB140-E3/54	V_RRM = 40 V, I_F = 1 A, DO-41, higher P_D = 1.0 W	Higher current capacity but 35 ns t_rr and larger thermal mass	Prefer for >500 mA average loads where thermal margin outweighs speed penalty

Compared with 1N5817-T and SB140-E3/54, SD103A-T delivers superior high-frequency performance (10 ns vs. ≥35 ns) and compact DO-35 form factor, making it optimal for space-constrained, high-switching-frequency DC-DC stages where low V_F and fast recovery are critical.

Availability

SD103A-T is available at Aetrix Electronics and suitable for DC-DC converter output rectification, low-voltage freewheeling paths, and USB port protection requiring stable component supply and consistent DO-35 mechanical fit.

Supply support for SD103A-T 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

The SD103x series targets cost-sensitive, high-volume power management applications demanding fast switching, low forward drop, and robust transient tolerance in compact through-hole packages.

FAQ

What is the maximum junction temperature for SD103A-T?

The SD103A-T has a specified operating junction temperature range of –55 °C to +125 °C. This limit is enforced by its 300 °C/W thermal resistance and 400 mW power dissipation rating at 25 °C ambient. Exceeding 125 °C risks parametric shift and accelerated degradation of the Schottky barrier interface.

Is SD103A-T suitable for surface-mount assembly?

No - SD103A-T uses a DO-35 glass axial package with radial leads intended for through-hole mounting. It lacks solder pads or land patterns compatible with reflow or wave soldering for SMT lines. For SMT equivalents, consider Diodes Inc.'s AP103 series in SOD-123.

How does guard ring construction improve reliability?

The guard ring in SD103A-T is a diffused p-type region surrounding the active Schottky junction. It redistributes electric field gradients at the silicon-glass interface, suppressing edge breakdown during voltage transients and enabling reliable operation under 15 A surge conditions without catastrophic failure.

What is the reverse leakage current at 30 V?

At 30 V reverse bias and 25 °C, SD103A-T exhibits a maximum reverse current (I_RM) of 5.0 μA. This value is specified in the datasheet under "Electrical Characteristics" and reflects typical leakage for a 40 V-rated Schottky diode with glass passivation.

SD103A-T Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: DO-204AH, DO-35, Axial

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Technology:: Schottky

Voltage - DC Reverse (Vr) (Max):: 40 V

Current - Average Rectified (Io):: 350mA

Voltage - Forward (Vf) (Max) @ If:: 600 mV @ 200 mA

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

Reverse Recovery Time (trr):: 10 ns

Current - Reverse Leakage @ Vr:: 5 µA @ 30 V

Capacitance @ Vr, F:: 50pF @ 0V, 1MHz

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-35

Operating Temperature - Junction:: 125°C (Max)

SD103A-T FAQ

1.How can I place an order for SD103A-T through Aetrix?

Please submit a Request for Quotation (RFQ) for SD103A-T 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 SD103A-T reliable?

The price and inventory of SD103A-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SD103A-T is usually 5 days.

3.What payment methods are accepted for SD103A-T?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SD103A-T transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SD103A-T?

SD103A-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SD103A-T 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 SD103A-T?

For technical support, including SD103A-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SD103A-T requirements.

6.How does Aetrix verify that SD103A-T is sourced from the original manufacturer or authorized distributors?

All SD103A-T 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 SD103A-T meets industry standards.

7.What is the process for return or replacement of SD103A-T?

All SD103A-T units undergo pre-shipment inspection (PSI). If there is an issue with SD103A-T, 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 SD103A-T part is unused and in its original packaging.

Return procedure for SD103A-T:

1.Submit a request within 90 days.

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

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