Schottky Diodes — Low Forward Voltage, High-Speed Switching

Schottky barrier diodes are semiconductor devices that use a metal-semiconductor junction instead of a traditional PN junction, delivering significantly lower forward voltage drop and near-zero reverse recovery charge. This makes Schottky diodes the preferred choice for high-frequency switching power supplies, DC-DC converters, reverse polarity protection, and OR-ing circuits where efficiency and speed are critical. At ADD Components, we supply Schottky diodes from Vishay, ON Semiconductor, STMicroelectronics, Nexperia, and Diodes Incorporated, supporting procurement teams with real, factory-original parts at competitive pricing. This guide explains the categories of Schottky diodes, key parameters, and a comprehensive parts table of popular components we source regularly for customers across Asia and beyond.

Sub-Types / Categories

Small Signal Schottky Diodes

Small signal Schottky diodes operate at currents below 500 mA and are optimised for high-speed switching, clamping, and detection circuits. With forward voltage drops as low as 0.24 V and switching speeds in the picosecond range, they excel in RF detection, logic-level clamping, and battery-powered portable devices where every millivolt of voltage headroom matters. Popular through-hole diode parts include the BAT46 (100 V, 150 mA) from STMicroelectronics, which offers a rare combination of high voltage and Schottky characteristics. Nexperia's BAT54 series provides dual and single SMD diode configurations in the tiny SOT-23 package, making them ubiquitous in compact consumer electronics. These diodes bridge the gap between general-purpose switching diodes like the 1N4148 and higher-current Schottky rectifiers.

Standard Schottky Rectifiers (1 A to 10 A)

Standard Schottky rectifiers in the 1 A to 10 A range serve as output rectifiers in low to medium-power switch-mode power supplies, freewheeling diodes in buck converters, and reverse battery protection elements. Their forward voltage drop typically ranges from 0.3 V to 0.55 V, roughly half that of comparable PN junction rectifiers, translating to a 40 to 50 percent reduction in conduction losses. The 1N5819 (40 V, 1 A) and 1N5822 (40 V, 3 A) are industry-standard through-hole Schottky diodes found in countless power supply designs. The SS14 (40 V, 1 A) from Diodes Incorporated and Vishay is the SMD equivalent in SMA package, while the B360A (60 V, 3 A, SMC) covers mid-range voltage requirements. Nexperia's PMEG series brings AEC-Q101 qualified automotive-grade Schottky diodes to the portfolio, suitable for demanding under-hood applications.

Power Schottky Diodes

Power Schottky diodes handle currents from 10 A to over 100 A and voltages up to 200 V, catering to high-power DC-DC converters, server power supplies, solar inverters, and automotive alternator rectification. These devices are typically housed in TO-220, TO-247, or D2PAK packages with low thermal resistance to facilitate effective heatsinking. ON Semiconductor's MBR series, such as the MBR20100CT (100 V, 20 A, TO-220), uses a dual common-cathode configuration ideal for centre-tapped secondary rectification. STMicroelectronics' STPS30L45CT (45 V, 30 A, TO-220) targets low-voltage, high-current applications where minimising forward voltage drop is paramount. Vishay's VSS series in Surface-Mount PowerDpak and DPAK packages provides compact, thermally efficient SMD diode solutions for automated assembly. When selecting power Schottky diodes, trade leakage current against forward voltage drop: higher voltage ratings increase leakage current, which can become a significant loss mechanism at elevated junction temperatures.

Key Selection Parameters

• Forward Voltage Drop (VF): The defining characteristic of Schottky diodes. Lower VF reduces conduction losses but may come at the expense of higher reverse leakage. Compare VF at the actual operating current, not just the diode's maximum rating.

• Reverse Breakdown Voltage (VRRM): Schottky diodes are typically limited to 200 V or below. Derate appropriately for ringing and transient overshoot in switching converters.

• Reverse Leakage Current (IR): Schottky diodes exhibit significantly higher leakage than PN junction diodes, and leakage doubles approximately every 10°C to 25°C. Evaluate worst-case leakage at maximum operating temperature.

• Average Forward Current (IF(AV)): Ensure sufficient current margin, considering that Schottky diodes run hotter due to conduction losses and have lower maximum junction temperatures (typically 125°C to 175°C) than PN rectifiers.

• Junction Capacitance (CJ): Low junction capacitance supports high-frequency operation. Important for resonant converters and snubber circuits.

• Package Type: Through-hole diode packages (DO-41, DO-201AD, TO-220) for prototyping and repair. Surface mount diode packages (SMA, SMB, SMC, SOD-123, SOT-23, DPAK, D2PAK) for automated production.

• Qualification Standards: AEC-Q101 qualification required for automotive applications. Check manufacturer datasheets for compliance.

Representative Parts We Source

Send Us Your Diode Requirements

ADD Components stocks and sources Schottky diodes across the full spectrum from small signal to high-power devices. Whether your design calls for a conventional 1N5819 in through-hole packaging, a compact BAT54S in SOT-23, or a high-current MBR20100CT in TO-220, we provide authentic manufacturer-original parts with full traceability. Our procurement team also supports alternative source identification and cost-reduction proposals for your existing bill of materials.

Share your part numbers or BOM with us for a fast quotation. We ship internationally and maintain strong relationships with Vishay, ON Semiconductor, STMicroelectronics, Nexperia, and Diodes Incorporated to secure the best lead times and pricing for our customers.

Email: Info@addcomponents.hk | Tel: +852 5334 3091 | WhatsApp: +852 5334 3091

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