📌 Core Function: Rectification

Both standard PN junction rectifier diodes and Schottky diodes share a fundamental role: converting AC to DC.

They exploit the diode’s unidirectional conduction:

Forward-biased: current flows
Reverse-biased: current is blocked

Typical circuits: half-wave, full-wave, and bridge rectifiers.

👉 For full-wave rectification, the average DC output is approximately 0.9 × AC input (RMS). For half-wave rectification, it is about 0.45 × AC RMS. Real circuits are slightly lower due to diode forward voltage drop and capacitor ripple.

Rectifier Diodes vs Schottky Diodes: Key Differences and Selection Guide-Protection Devices-TVS Diodes-ESD Protection devices-Gas Discharge Tube-Thyristor-Pled Protectors-Mov

📌 Structure Defines Performance

ParameterStandard PN Junction DiodeSchottky Diode
Forward Voltage (Vf)0.7–1.1 V0.2–0.5 V
Switching SpeedLimited by reverse recovery timeNear-zero reverse recovery
Reverse LeakageLowHigher, increases with temperature
Reverse Voltage (Vr)High, up to several kVSilicon: 20–200 V; SiC: 600–1700 V
Key FeatureHigh voltage tolerance, robust, low costHigh efficiency, fast switching, low voltage drop

📌 Switching Speed

A major difference lies in reverse recovery time:

Standard PN diodes:

  • Mains rectifiers: μs range
  • Fast-recovery diodes: tens to hundreds of ns
  • Ultra-fast recovery: tens of ns

Schottky diodes:

  • Almost no reverse recovery charge
  • Ideal for high-frequency switching applications

📌 Reverse Voltage Capability

A common misconception is that Schottky diodes are always “low voltage.”

Silicon Schottky: 20–200 V
SiC Schottky: 600–1700 V

This makes Schottky suitable even for high-voltage applications like EV on-board chargers, photovoltaic inverters, and high-voltage DC-DC converters.

📌 Typical Applications

Schottky Diodes:

  • Low-voltage, high-current rectification (5 V, 12 V DC-DC converters, chargers)
  • High-frequency switching power supplies
  • Reverse-polarity protection / OR-ing circuits
  • RF detection, clamping
  • SiC Schottky: EV OBC, photovoltaic inverters, high-voltage DC-DC

Standard PN Diodes:

  • AC mains rectification (50/60 Hz)
  • High-voltage rectification (industrial power supplies)
  • Cost-sensitive designs

📌 Summary and Selection Guide

High efficiency (low loss), low voltage, high current, high frequency and high speed - Schottky diode

High reverse withstand voltage, high junction temperature, low cost, power frequency or low frequency - General purpose rectifier diode (PN junction)