Silicon & Schottky Diodes in Rectification: Working, Benefits

Introduction : Rectification refers to converting AC to DC. It is a core requirement in most power electronics. Silicon diodes and Schottky diodes are widely used for this purpose; each brings distinct electrical characteristics. This application note explores how these diodes work in rectifier circuits and compares their benefits such as low forward voltage drop (especially for Schottky), speed, efficiency and handling.

Use of Diodes in Rectifier Circuits & working

The figure-1 depicts half wave rectifier. As shown, it uses single diodes which conducts during positive half cycles only.

The figure-2 depicts full wave rectifier. As shown, it uses center-tap transformer and two diodes. In this configuration, one diode conducts during positive half cycle and the other diode conducts during negative half cycle.

Following are the benefits of full wave over half wave rectification.

• 100% conduction efficiency
• Better transformer utilization
• Higher frequency ripple

The figure-3 depicts bridge rectifier. Bridge rectifiers use four diodes in bridge configuration for optimal performance. Following are the benefits of bridge rectifier over other types.

• No center tap transformer required
• Best transformer utilization
• Balanced operation

Advantages of diode in Rectification

Following are some of the benefits of diode based rectification circuits.

1. Full wave rectifiers provide higher efficiency and better utilization of AC waveform compared to half wave rectifiers.
2. Full wave or bridge rectification reduces ripples in the output. Hence less filtering is required.
3. Bridge rectifier uses four diodes and center tap transformer is not needed. This reduces complexity and cost consecutively.
4. Diodes are solid state and have no moving parts which makes these rectifier circuits more reliable and robust.
5. Diodes respond very quickly to forward or reverse conditions. This helps rectifier switch states reliably at each half cycles.

Conclusion: Both silicon and Schottky diodes excel in rectification settings, with silicon providing high reverse voltage tolerance and Schottky offering fast switching and lower forward voltage drop.