1N5817 – onsemi 20V 1A Schottky Barrier Rectifier Diode

Product Overview

The 1N5817 is a Schottky barrier rectifier diode manufactured by onsemi. It is designed for low-voltage, high-efficiency rectification and fast switching applications, where low forward voltage drop and fast recovery are critical.

This device belongs to the 1N58xx Schottky diode family, widely used in DC/DC converters, power supplies, freewheeling circuits, and reverse polarity protection.

According to onsemi’s official documentation, the 1N5817 uses a Schottky barrier metal-to-silicon structure, providing low forward voltage drop, fast switching speed, and majority-carrier conduction with no reverse recovery charge, making it highly efficient for switching power applications.

Part Number Breakdown

• 1N → Standard JEDEC diode series
• 5817 → Schottky rectifier, 20V / 1A class device
• No suffix → Standard axial lead DO-41 package version

Competitive Advantages

✔ Very low forward voltage (~0.45V)
✔ High efficiency Schottky structure
✔ Fast switching, no reverse recovery
✔ 1A continuous current capability
✔ 20V low-voltage system compatibility
✔ Strong reliability over temperature range
✔ Easy through-hole DO-41 package
✔ Ideal for DC/DC and protection circuits

Key Features

1. Low Forward Voltage Drop

The 1N5817 uses Schottky barrier technology, which results in a very low forward voltage drop (~0.45V at 1A).

Benefits:

• Lower conduction loss compared to silicon PN diodes
• Higher efficiency in power circuits
• Reduced heat generation
• Ideal for low-voltage power rails (3.3V / 5V systems)

2. Fast Switching (No Reverse Recovery Charge)

As a majority-carrier device, the Schottky diode has negligible reverse recovery time.

Benefits:

• Suitable for high-frequency switching converters
• No reverse recovery losses
• Better efficiency in switching power supplies
• Ideal for fast rectification circuits

3. 20V Low-Voltage Rectification

The device is optimized for low-voltage applications (20V class).

Benefits:

• Ideal for 5V and 12V systems
• Suitable for DC/DC converter outputs
• Used in logic-level power protection
• Prevents reverse polarity damage

4. High Efficiency Power Conversion

The Schottky structure reduces energy loss significantly.

Benefits:

• Higher efficiency in SMPS designs
• Lower thermal stress
• Better battery-powered system performance
• Improved power density

5. Axial Lead DO-41 Package

The diode is packaged in a DO-41 through-hole axial format.

Benefits:

• Easy manual assembly
• Good thermal dissipation
• Suitable for prototyping and repair
• Strong mechanical reliability

Applications

DC/DC Converters

• Step-down and step-up converters
• Switching power supplies
• High-frequency rectifiers

Power Management Systems

• Load switching circuits
• Power OR-ing circuits
• Voltage drop protection

Reverse Polarity Protection

• Battery-powered devices
• Automotive low-voltage systems
• Embedded power inputs

Freewheeling / Flyback Circuits

• Relay coil suppression
• Motor driver protection
• Inductive load clamping

Consumer & Industrial Electronics

• Power adapters
• Embedded controllers
• Industrial control systems