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What is a Fast Rectifier?

Rectification is the most popular use for diodes. Fast rectifiers convert alternating current (AC) to direct current (DC). They only allow one-way flow of electrons. Rectifiers have many uses and are often found serving as components of high-voltage direct current power transmission systems and DC power supplies. Fast rectifier diodes feature very low reverse recovery time, very low switching losses and low noise turn-off switching.
Types of Fast Rectifiers
There are several different kinds of fast rectifiers. At Topdiode we offer many of the most common types categorized by maximum average rectified current, maximum reverse recovery time, maximum reverse current, maximum reverse voltage, packaging type and forward voltage. The most common sizes for forward voltage are 1.1 V, 1.2 V and 1.3 V.
 Applications for Fast Rectifiers:
Fast rectifier diodes are found in strobe applications that require high surge resistance as well as in the industrial, commercial and automotive sectors. High voltage resistance fast rectifier diodes, which are ideal for use in switching power supplies of all types, feature fast switching speeds along with improved efficiency and reduced loss. Fast rectifiers are also used in PDPs (sustain circuits) and PFC circuits. Also, detectors of radio signals serve as rectifiers.

Fast Recovery Rectifiers in Topdiode

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What is a Schottky Diode?

A Schottky diode, also known as a hot carrier diode, is a semiconductor diode which has a low forward voltage drop and a very fast switching action. There is a small voltage drop across the diode terminals when current flows through a diode. A normal diode will have a voltage drop between 0.6 to 1.7 volts, while a Schottky diode voltage drop is usually between 0.15 and 0.45 volts. This lower voltage drop provides better system efficiency and higher switching speed. In a Schottky diode, a semiconductor–metal junction is formed between a semiconductor and a metal, thus creating a Schottky barrier. The N-type semiconductor acts as the cathode and the metal side acts as the anode of the diode. This Schottky barrier results in both a low forward voltage drop and very fast switching.
Applications for Schottky Diodes:
Schottky diodes are useful in voltage clamping applications and prevention of transistor saturation due to the higher current density in the Schottky diode. Also, because of the low forward voltage drop in a Schottky diode, less energy is wasted as heat, therefore making them an efficient choice for applications that are sensitive to efficiency. Because of this, they are used in stand-alone photovoltaic systems in order to prevent batteries from discharging through the solar panels at night as well as in grid-connected systems containing multiple strings connected in parallel. Schottky diodes are also used as rectifiers in switched-mode power supplies. 

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What is a Standard Rectifier?

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.

Types of Standard Rectifiers
There are many different kinds of standard rectifiers and at Topdiode, we offer many of the most common types categorized by maximum reverse current, maximum peak current, maximum reverse voltage, forward voltage, packaging type and maximum average rectified current.

The most common sizes for maximum average rectified current are 1 A, 1.5 A, 3 A, 5 A and 6 A. We also carry standard rectifiers with maximum average rectified current as high as 400 A. Forward voltage can range from 1.1 mV to 1.3 kV, with the most common standard rectifier semiconductor chips having a forward voltage of 1.1 V or 1.15 V.

Applications for Standard Rectifiers:
Standard rectifiers can be found regulating the power in computers and the electrical power in motor vehicles. They can also be used in 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. For example, a diode is used in the detector of radios in order to perform radio demodulation.

Standard diode rectifiers in Topdiode:

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What is a Current Limiting Diode?

A current limiting diode, also known as a CLD, current regulating diode, diode connected transistor or constant current diode, regulates or limits current over a wide voltage range. Current limiting diodes consist of a JFET with the gate shorted to the source and function like a two-terminal current limiter or current source, much like voltage limiting Zener diodes. They allow a current passing through them to rise to a certain value and then level off at a specific value. Contrary to Zener diodes, these diodes keep the current constant instead of keeping the voltage constant. Current limiting diodes keep the current which is flowing through them unchanged when the voltage changes.
Applications for Current Limiting Diodes:
Current limiting diodes offer high performance and simplicity characteristics compared with bipolar transistors. They offer versatility in several circuit applications and superior performance regarding dynamic and impedance temperature drift. Some examples of devices using current limiting diodes are waveform generator circuits, timing circuits and battery chargers. Current limiting diodes can also be found as a constant current source for driving LEDs and can be used in order to replace holding coils in telephone connection devices.

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What is a schottky rectifiers？

Schottky rectifiers have been used for several years in the power supply industry. The primary advantages are switching speeds that approach zero time and very low forward voltage drop. The reverse recovery time of Schottky diodes provides extremely fast recovery characteristics. What little reverse recovery time they exhibit is dictated by their capacitance instead of minority carrier recombination such as in conventional PN junction rectifiers. This offers very little reverse current overshoot when switching the Schottky from a forward conducting mode to a reverse blocking state.
Applications for Schottky Rectifiers:
Schottky rectifiers are ideal for output stages of switching power supplies. The very fast switching speed of Schottky rectifiers allows them to be used in very high frequency applications such as very low power signals and switching diode requirements of less than 100 picoseconds. Other applications include power management circuits and other various rectifier circuits.

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What is a Small Signal Diode?

A small signal diode is a small non-linear semiconductor which is often used in electronic circuits where high frequencies or small currents are involved in television, radio and digital logic circuits. Small signal diodes are smaller in size compared to regular power diodes. The PN junction of a small signal diode is usually encapsulated in glass in order to protect it and generally has a black or red band at one end of its body identifying it as the cathode end of the terminal. Small signal diodes have lower current and power ratings in comparison to rectifier diodes but can function better in high frequency applications or in switching and clipping applications which deal with short-duration pulse waveforms.
Applications for Small Signal Diodes:
As previously mentioned, small signal diodes are often used in high frequency applications or in switching and clipping applications which deal with short-duration pulse waveforms. Small signal diodes are also found as a switch in rectifiers, snubbers, limiters, and wave-shaping circuits. Yet another application for small signal diodes is to create a regulated voltage supply where diodes are connected together in series in order to provide a constant DC voltage across the diode combination.

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What is a Tuning / Varactor Diode?

A tuning diode, also known as a varactor diode, variable capacitance diode, varicap diode or variable reactance diode, is a diode that has a variable capacitance which is a function of the voltage that is impressed on its terminals. Tuning / varactor diodes are operated reverse-biased, and therefore no current flows. However, since the thickness of the depletion zone varies with the applied bias voltage, the capacitance of the diode can be made to vary. Usually, the capacitance is inversely proportional to the depletion region thickness and the depletion region thickness is proportional to the square root of the applied voltage. Therefore, the capacitance is inversely proportional to the square root of the voltage applied to the diode.

Applications for Tuning / Varactor Diodes:
Tuning / varactor diodes are often used in RF design. They provide a way of varying the capacitance within a circuit by applying a control voltage. Due to this capability, tuning / varactor diodes are widely used in the RF industry. They can be found in voltage controlled oscillators such as in a phase locked loop and are used in almost all radio, cellular and wireless receivers. They can also be found in RF filters for tuning purposes (for example, as tuners of television sets to electronically tune the receiver to different stations), parametric amplifiers, parametric oscillators and frequency synthesizers.

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What is an Ultrafast Rectifier?

Ultrafast rectifiers are designed in order to have very low forward voltage with an ultrafast reverse recovery. This makes ultrafast rectifier diodes very efficient for secondary output rectifications in high frequency switched mode power supplies. Ultrafast rectifiers can directly reduce switching loss and improve overall power efficiency due to a good combination between reverse recovery time and forward voltage. Some features and benefits include high reverse voltage surge capability, high thermal cycling performance, low thermal resistance and very low on-state loss. Also, the soft recovery characteristic of ultrafast rectifiers minimizes power consuming oscillations.
Applications for Ultrafast Rectifiers:
Ultrafast Rectifiers are made for negative switching power supplies, as free wheeling diodes (such as in motor applications) and for use in inverters. They can also be found in military and other high reliability applications. Other regular applications include desktop personal computers, laptop and printer AC adaptors, DVD AC/DC power supplies, monitors, televisions and games units.

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What is a Transistor?
A transistor is a semiconductor containing a solid, non-moving part that passes a charge. A transistor can amplify and switch electronic signals and electrical power

and is made of semiconductor material with at least three terminals that are used to connect to an external circuit. Transistors can amplify a signal because output

power can be higher than input power. By applying a voltage or a current to one of the terminal pairs, there is a change in current through another pair of terminals.
Applications for Transistors:
There are many applications that use transistors including:
Logic gates
General switching
Amplification and sound reproduction
Signal processing
Radio transmission
Transistors in Topdiode

Transistors in Topdiode

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What is a TVS Diode?

The Transient Voltage Suppressor diode (also known as a TVS Diode) is a protection diode designed to protect electronic circuits against transients and overvoltage

 threats such as EFT (electrically fast transients) and ESD (electro-static discharge). TVS Diodes are silicon avalanche devices typically chosen for their fast response

 time (low clamping voltage), lower capacitance and low leakage current. 

When selecting TVS Diodes there are some important parameters to be considered, these are; Reverse Standoff Voltage (VR), Peak Pulse Current (IPP) and Maximum

 Clamping Voltage (VC max). 

Applications for TVS diode

Cordless Phone, Desktop, Notebook, Dish washer, DSL Modem Router, Ethernet Router, LCD Projector, LCD TV, Microprocessor Controlled Dimmer, Microwave Oven,

 Power Supply, Room AC, Set Top Box, SLIC Line Card, SMPS Embedded, Solar Power System (Residential), T1/T3 Line Driver, VoIP Telephone Adapter

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