Help with High Voltage Diodes specifications:
General Specifications
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| Diode Type | |||
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| General Purpose (PN Junction Diodes) | PN junction diodes are used for general-purpose applications. They are also known as PN diodes, PN junctions, and small-signal diodes. | ||
| Zener Diodes | Zener diodes act as normal rectifiers until the applied voltage reaches a certain point. At this point (the Zener voltage or avalanche voltage), the diode conducts. | ||
| Schottky Barrier Diodes | Schottky diodes, in their simplest form, consist of a metal layer that contacts a semiconducting element. This metal/semiconductor junction exhibits rectifying behavior (i.e., the current passes through the structure more readily with one polarity than the other). Schottky diodes are used primarily in high frequency and fast-switching applications. Because they operate only with majority carriers, there is no reverse leakage current as with other types of diodes. With Schottky diodes, the metal region is heavily occupied with conduction-band electrons. The N-type semiconductor region is lightly doped. When forward-biased, the higher energy electrons in the N-region are injected into the metal region, where they give up their excess energy very rapidly. Since there are no minority carriers (as with conventional rectifier diodes), there is a very rapid response to a change in bias. For this reason, Schottky diodes are used in high-frequency applications and in many digital circuits to decrease switching times. Schottky diodes are also known as hot-carrier diodes. | ||
| PIN Diodes | PIN diodes are three-layer semiconductor diodes consisting of an intrinsic layer separating heavily doped P and N layers. The charge stored in the intrinsic layer, in conjunction with other diode parameters, determines the resistance of the diode at RF and microwave frequencies. Typically, this resistance ranges from kilohms to less than 1 ohm for a given diode. PIN diodes are often used as switches or attenuator elements. | ||
| Varactor Diodes | Varactor diodes are P-N junction diodes that act as voltage-controlled capacitors when operated under reverse bias. P-N junctions have inherent capacitance. When the junction is reverse biased, increasing the applied voltage causes the depletion region to widen, thus increasing the effective distance between the two "plates" of the capacitor and decreasing the effective capacitance. By adjusting the doping gradient and junction width, the capacitance range can be controlled, and the way-capacitance changes with the applied reverse voltage. A four-to-one capacitance range is not problematic. In fact, a typical varactor diode (sometimes called a "varicap diode") can vary from 60 picofarads (pf) at zero-bias down to 15 pf at 20 volts (V). Precision manufacturing can achieve a capacitance range of up to ten-to-one. Typically, varactor diodes are used in electronic tuning systems to eliminate the use of and need for moving parts. | ||
| Step-recovery Diodes | Step-recovery diodes or snap-off diodes use graded doping where the doping level of the semiconductive materials is reduced as the PN junction is approached. This produces an abrupt turn-off time by allowing a very fast release of stored charge when switching from forward to reverse bias. It also allows a rapid re-establishment of forward current when switching from reverse to forward bias. Step-recover diodes are used in very high frequency (VHF) and fast-switching applications. | ||
| Tunnel Diodes | Tunnel diodes are heavily doped P-N diodes in which electron tunneling from the conduction band in the N-type material to the valence band in the P-type region produces a region of negative resistance. The most important region of operation for tunnel diodes is this negative resistance region where, as the voltage is increased, the current decreases. This feature makes tunnel diodes very useful in oscillators and RF applications. | ||
| RF Diodes | RF diodes are designed to handle high-power radio frequency (RF) signals in devices such as stereo amplifiers, radio transmitters, television monitors, and other radio frequency or microwave devices. | ||
| Transient Voltage Suppressor Diodes (TVS) | Transient voltage suppressor (TVS) diodes are semiconductor diodes that are specifically designed to limit over-voltages. TVS diodes can dissipate high transient power in short amounts of time. | ||
| Current Limiting Diodes | Current limiting diodes (CLD) regulate current over a wide voltage range. There are several types of current limiting diodes (CLD). Examples include current regulator diodes, constant current diodes, and current limit diodes. | ||
| Gunn Diodes | Gunn diodes or transfer electron devices (TED) exhibit a negative resistance region. They are used in high-frequency applications, often for building RF oscillators. | ||
| IMPATT Diodes | Impact ionization avalanche transit-time (IMPATT) diodes are designed to operate at very high frequency and power. They are used as elements in RF and microwave devices. | ||
| Other | Other unlisted or proprietary diode types. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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RoHS Compliance
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| RoHS Compliant | Restriction of Hazardous Substances (RoHS) is a European Union (EU) directive that requires all manufacturers of electronic and electrical equipment sold in Europe to demonstrate that their products contain only minimal levels of the following hazardous substances: lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyl, and polybrominated diphenyl ether. RoHS will become effective on July 1, 2006. | ||
| Search Logic: | "Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice. | ||
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Performance
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| VRRM | Repetitive peak reverse voltage or maximum reverse voltage (VRRM) is the maximum allowable instantaneous value of reverse voltage repeatedly applicable. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| IF | IF is the current value when the specified forward voltage (VF) is applied. It is also defined as the current flowing through the diode in the direction of lower resistance. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| trr | Reverse recovery time (trr) is the time taken for the reverse current (IR) to reach a specified level when the reverse voltage is applied while the device is conducting in the forward direction. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| VF | VF is the forward voltage at specified forward current input. It is also defined as the voltage across the diode terminals that results from the flow of current in the forward direction. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| IR | Reverse current (IR) is the current value when the specified reverse voltage is applied. It is the current that flows when reverse bias is applied to a semiconductor junction. Reverse current is also known as leakage current. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| PD | This is the maximum permissible power dissipation (PD) per output (in W) of the diode at specified ambient temperature. Power dissipation is the power dissipated by the diode while in the ON state. | ||
| Search Logic: | User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria. | ||
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| Tj | Junction operating temperature (Tj) is the range of temperatures over which the diode is designed to operate. | ||
| Search Logic: | User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria. | ||
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Lead Type
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| Your choices are... | |||
| Axial Leads | Axial leads extend from the diode's ends and along its axis. | ||
| Radial Leads | Radial leads extend from the diode's sides instead of from its ends. | ||
| Flying Leads | Flying leads project horizontally from the diode. | ||
| No Leads (SMT) | Diodes that use surface mount technology (SMT) do not have leads. Instead, they are pad-mounted. | ||
| Tab Leads | Tab leads are terminals designed for direct mounting into a circuit board socket. | ||
| Screw / Insert Leads | The diode's leads are designed to be fastened by screw. | ||
| Gull Wing Leads | Gull-wing leads are popular because they are relatively inexpensive to mold and form. They are flexible enough to withstand thermal expansion and contraction. Inspecting the integrity of the gull-wing lead to circuit board solder connection is relatively easy. | ||
| J - Leads | J-leads use less board space than gull-wing leads. However, because these lead-to-board solder connections are hidden from inspection, they are more difficult to form. | ||
| Other | Other unlisted lead types. | ||
| Search Logic: | All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches. | ||
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