What Is Rectifier Diode?


Diodes are common semiconductor devices. A rectifier diode, a two-lead semiconductor provides only one direction of current to flow. In general, the P-N junction diode is created by fusing n-type and p-type semiconductor materials. The anode is the P-type side, and the cathode is the n-type side. Many different types of diodes are widely used in a variety of applications. Rectifier diodes are a crucial component in power supplies because they convert AC voltage to DC voltage. Zener diodes are used to regulate voltage and prevent unwanted variations in DC supplies within a circuit.


Ⅰ Introduction

Ⅱ What is a Rectifier ?

Ⅲ Rectifier Diode Related Video

Ⅳ What is the Rectifier Diode?

Ⅴ What are the Differences Between Diode and Rectifier?

Ⅵ Technical Parameters

Ⅶ Rectifier Diode – Current-voltage Characteristics

Ⅷ Applications

Ⅸ Rectifier Diode Circuit Working

Ⅹ How to test Rectifier Diode?


Ⅱ What is a Rectifier ?

A rectifier converts alternating current (AC), reversing direction on a regular basis, to direct current (DC), which flows in only one direction. The inverter performs the reverse operation.

Rectifiers are applied to convert alternating current (AC) to direct current (DC). Nowadays, two types of rectifiers are in use. The bridge rectifier is one of the most common types of rectifiers. It generates electricity and converts it from direct current to direct current. The following are the other types of rectifiers:

Single-phase rectifiers

  • Three-phase rectifiers

  • Half-wave rectifiers

  • Full-wave rectifiers

  • Controlled rectifiers

  • Uncontrolled rectifiers

  • Centre tapped rectifiers

What is a Rectifier? (AC to DC): Electronics Basics 7

Rectifier Diode Video Description : This video will explained what is  the Retifier and some basic circuits.

Ⅳ What is the Rectifier Diode?

A rectifier diode is a semiconductor diode that is used in the rectifier bridge application to convert AC (alternating current) to DC (direct current). Within digital electronics, it has a tremendous value of using the rectifier diode via the Schottky barrier. This diode can control currents ranging from mA to a few kA and voltages ranging from a few kV to a few kV.

Rectifier diodes can be designed using Silicon material and are capable of carrying high electric current values. These are not well-known diodes, but they are still used in Ge or gallium arsenide-based semiconductor diodes. Ge diodes have a lower reversed voltage allowable as well as a lower junction temperature allowable. Compared with the Si diode, the Ge diode has an advantage that creates a lower threshold voltage value while operating in forward bias.

There are two types of technical parameters in a rectifier diode: permissible limit parameters and characteristic parameters. A rectifier diode symbol is shown below, with the arrowhead pointing in the direction of conventional current flow.

Figure1: Rectifier Diode Symbol

Ⅴ What are the Differences Between Diode and Rectifier?

A rectifier is applied to convert AC, whereas a diode is considered a switching device. There are some other distinctions between the two, such as:

  • When a diode is forward biased, it allows current to flow. The diode prevents the current from flowing backward. In contrast, a rectifier is composed of a transformer, a diode, and a filter circuit. All of these work together to convert AC to DC.

  • The current-carrying capacity of diodes is low, whereas the position in rectifiers is high.

  • Zener diodes, photodiodes, and other types of diodes are examples. Rectifiers are classified into two types: single-phase and three-phase. Full-wave rectifiers and half-wave rectifiers are subcategories of single-phase rectifiers.

  • Rectifiers are found in computers, whereas diodes are found in switches and clippers.

  • Initially, diodes were referred to as valves. Most of the time, they are made of germanium or silicon.

Ⅵ Technical Parameters

Silicon is the most commonly used material for rectifier diodes (semiconductor crystal). They can conduct large amounts of electric current, which is their primary characteristic. There are also less common, but still used, germanium or gallium arsenide semiconductor diodes. Germanium diodes have a much lower permissible reversed voltage and a much lower permissible junction temperature (Tj = 75° C versus Tj = 150° C for silicon diodes). The only advantage that germanium diodes have over silicon diodes is that they have a lower threshold voltage value when operating in forward bias (VF(I0) = 0.3 0.5V for germanium and 0.7 1.4V for silicon diodes).

We divide the rectifier diode's technical parameters into two groups (they also apply to other semiconductor diodes):

  • permissible limit parameters,

  • characteristic parameters.

  1. VF – Forward voltage as determined by the IF forwarding current

  2. IR – The reverse current at VRWM peak reverse voltage operation.

  3. IFN – The maximum average current or rated current of a diode in forward bias.

  4. Peak, Repeatable Current Diode Conduction (IFRM)

  5. Peak, non-repeatable current conduction (IFSM)

  6. VRWM stands for Peak, Reverse Voltage Operation.

  7. VRRM stands for Peak, Repetitive Reverse Voltage.

  8. VRSM stands for Peak, Non-Repetitive Reverse Voltage.

  9. PTOT – The total value of the power dissipated on the electronic component.

  10. Tj – Maximum Junction Temperature in a Diode Rth – Thermal Resistance Below Operating Conditions

Ⅶ Rectifier Diode – Current-voltage Characteristics

The below picture shows the  rectifier diode Current-voltage characteristics :

Figure2: Current-Voltage characteristics of the Rectifier Diode

Ⅷ Applications

Rectifier diodes have a wide range of applications. Here are a few examples of common diode applications:

  • Rectifying a voltage, such as converting AC voltages to DC voltages

  • Signal isolation from a supply

  • Referencing Voltage

  • Changing the size of a signal

  • Signal blending

  • Signals of detection

  • System of lighting

  • Diodes for lasers

Ⅸ Rectifier Diode Circuit Working

Both n-type and p-type materials are chemically combined with a special fabrication technique to form a p-n junction. Because this P-N junction has two terminals that can be regarded as electrodes, it is referred to as a "DIODE" (Di-ode). Biasing occurs when an external DC supply voltage is applied to any electronic device via its terminals.

Unbiased Rectifier Diode

In the case of no voltage, rectifier diode is referred to as an Unbiased Diode.N-side will generate a majority number of electrons, and very few numbers holes (due to thermal excitation) on the contrary, the P- side will have a majority of charge carriers holes and very few numbers of electrons.Free electrons from the N-side diffuse (spread) into the P side and recombine in holes, resulting in +ve immobile (not moveable) ions on the N-side and -ve immobile ions on the P side of the diode.

TThe immobile near the junction edge on the n-type side. Similarly, immobile ions near the junction edge on the p-type side. As a result, a large number of positive and negative ions will accumulate at the junction. This newly formed region is known as a depletion region.

A static electric field known as the Barrier Potential is created across the PN junction of the diode in this region.

It prevents further hole and electron migration across the junction.

Forward Biased

Reverse Biased Diode

Minority carriers in p-type and n-type semiconductors are primarily thermally generated electrons/holes.

Now, if the reverse applied voltage across the diode is continuously increased, the depletion layer will destroy after a specific voltage, causing a massive reverse current to flow through the diode.

This is known as carrier multiplication, and it results in a significant increase in the flow of current through the p-n junction. Avalanche Breakdown is the name given to the associated phenomenon.

Reverse Biased Diode

Ⅹ How to test Rectifier Diode?

The polarity of a rectifier diode can be determined using the most basic multimeters (where is the anode and where is the cathode). There are at least three ways to do this, but I'll show you the two simplest:

Using ohmmeter (2kΩ range):

In forward-bias mode, the Ohmmeter will display the estimated value of the diode's forward voltage, which is close to 0.07. In reverse-bias, the ohmmeter will read "1," indicating extremely high resistance.

The function of a diode check will produce the same result as the previously mentioned method.

Forward-bias: An ohmmeter will show the approximate value of the diode's forward voltage (near 0,7V)

Reverse-bias: The ohmmeter reads "1," indicating that the resistance is extremely high (electric valve off)

A "diode check" function will produce the same result as the method described above.

Using VDC measurement function:

A multimeter will show that the voltage drop for a silicon diode in forward bias is 0.7V.

A multimeter is used in reverse-bias to specify the estimated value of the full voltage supply.

Forward-bias: For silicon diodes, a voltage drop of about 0.7% should be visible on a multimeter.


Reverse-bias: A multimeter will show the approximate full voltage value of the supply (Note: In this example, the diode is inserted in the opposite direction as in the previous example. In reality, I would reverse the polarity of the Power Supply because you can't unmount a soldered component "with your hands" unless you desolder it. Of course, we do not want to jeopardize the good operating component.The purpose of this example is to show why you should take care of component placement on your PCB or breadboard.)


1. How does a rectifier diode work?

A rectifier is a device that converts an Alternating Current (AC) into a Direct Current (DC) by using one or more contact diodes. ... In simple words, a diode allows current in just one direction. This unique property of the diode allows it to act sort of a rectifier by converting an alternating current to a DC source.

2. What is a rectifier used for?

Essentially, a rectifier is an electrical device used to convert alternating current (AC) into direct current (DC) by allowing a current to flow through the device in one direction only. Diodes work like one-way valves within the rectifier to maintain this flow of current.

3. Why diode can be used as a rectifier?

An ideal p-n junction diode has zero resistance in forward direction and infinite resistance in reverse bias. This can be used to eliminate the negative cycles in an AC voltage waveform and allow only the positive cycles. This process is called rectification and is useful in many applications like AC to DC conversion.

4. What is rectifier and its types?

Rectifiers are used in a variety of devices and can be applied to modify network systems. ... On the whole, rectifiers can be classified into two types – single phase and three phase. Drilling down another level, they can then be separated into half wave, full wave and bridge rectifiers.

5. What is the most widely used rectifier?

A widely used rectifier is the three phase, 6 pulse, diode bridge rectifier. It's main use is low voltage motor drive front end. The single phase uncontrolled full wave bridge rectifier circuit configuration (four diodes arranged in a bridge circuit) is the most widely used rectifier configuration today.

6. What are the three types of rectifier?

The Different Types of Rectifiers

Single Phase & Three Phase Rectifiers.

Half Wave & Full Wave Rectifiers.

Bridge Rectifiers.

Uncontrolled & Controlled Rectifiers.

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