A rectifier diode lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes can handle higher current flow than regular diodes and are generally used in order to change alternating current into direct current. They are designed as discrete components or as integrated circuits and are usually fabricated from silicon and characterized by a fairly large P-N-junction surface. This results in high capacitance under reverse-bias conditions. In high-voltage supplies, two rectifier diodes or more may be connected in series in order to increase the peak-inverse-voltage (PIV) rating of the combination.

Standard rectifiers can be found regulating the power in computers, battery chargers for rechargeable batteries, computer power supplies and vehicle batteries. Also, while rectifier diodes are often used for AC to DC conversion, diodes with rectifying characteristics are found in other uses than in electronics.

General Purpose Rectifier Diode