Dioden
Produkte (171)
UM9993 - Obsolete Microchip RF/Microwave Diode | EOL 2025
The Microchip UM9993 is an obsolete RF/Microwave Diode originally designed for commercial, defense, and aerospace applications. Per Microchip product discontinuation notice MFOL-19MRQH667, the UM9993 reached end-of-life effective 2025-06-26 with no further supply and no announced suggested replacement. The part is listed by Microchip Technology, which acquired the legacy UM-series RF diode family originally marketed for high-frequency signal conditioning, detection, and switching subsystems used in radar, electronic warfare, and aerospace RF front-ends. An RF/Microwave diode is a specialized two-terminal semiconductor device optimized to operate at radio and microwave frequencies (from roughly 100 MHz up to mmWave bands). This category of discrete component is used as a detector, mixer, switch, attenuator, or limiter depending on the underlying junction construction (Schottky, PIN, varactor, or step-recovery). RF/Microwave diodes sit inside the broader taxonomy: passive and active discrete semiconductors -> diodes -> small-signal diodes -> RF/Microwave diodes. They differ from rectifier diodes by their controlled junction capacitance, low series resistance, and tight parametric tolerances, which together determine cutoff frequency (ft), switching speed, and harmonic performance. Key documented facts: lifecycle status is End-of-Life with no further supply, the manufacturer is Microchip, the suggested replacement is N/A per the same notice, and prior distribution channels include UppConn Components GmbH and MicrochipDirect. Because the part is no longer being produced, sourcing is limited to specialty brokers, and long-term defense programs that qualified the UM9993 must transition to a replacement part or a designed-in substitute. Typical applications historically served by this series include RF detector circuits in radar and microwave receivers, mixer stages in up/down-converters, transmit/receive switching, and limiter front-ends for receiver protection. Defense and aerospace programs are the named target use cases per legacy marketing collateral. When designing, note that no parametric specifications are available in Microchip's modern product page (the part has been removed) and no current RoHS/REACH certificate for the UM9993 is published. New designs should not select UM9993 unless qualified by an existing military/aerospace build standard. Where possible, select a current Microchip RF Schottky or PIN diode family member whose package and electrical parameters have been re-qualified, or work with a franchised distributor to validate remaining inventory against program requirements. This page synthesizes manufacturer discontinuation records, broker listings, and lifecycle data into a single practical reference for engineers managing last-time-buy decisions on the UM9993.
VS-30BQ015-M3/9AT - 3A 15V Schottky Rectifier SMC | Vishay
The Vishay VS-30BQ015-M3/9AT is a 3.0 A surface-mount Schottky rectifier rated at 15 V reverse voltage, housed in a DO-214AB (SMC) package. It is built on Vishay's proprietary barrier technology that delivers ultra-low forward voltage drop, a guard ring for enhanced ruggedness and long-term reliability, and 125 °C junction temperature operation at reduced reverse bias. A Schottky rectifier is a semiconductor diode that uses a metal-semiconductor junction instead of a PN junction, producing a lower forward voltage drop (typically 0.3-0.5 V versus 0.7-1.0 V for PN-junction rectifiers) and faster switching. Schottky rectifiers sit within the diode family, which itself belongs to discrete semiconductors used for rectification, freewheeling, and reverse-polarity protection. They are preferred in low-voltage, high-efficiency power conversion stages where conduction losses dominate. Key features include a forward current of 3.0 A at TC = 105 °C, repetitive peak reverse voltage (VRRM) of 15 V, ultralow forward voltage drop, guard-ring construction that improves avalanche robustness, and RoHS-compliant matte-tin terminations. The single-die design minimizes thermal resistance and enables compact PCB placement in dense power layouts. Technically, the device uses a Schottky barrier with controlled leakage current across the rated reverse voltage. Its low VF reduces conduction loss, while the guard-ring suppresses edge breakdown that traditionally limits Schottky reliability. The trade-off is a higher reverse leakage than a PN rectifier of equivalent rating - acceptable in low-voltage (<30 V) rails but not in high-voltage applications. Typical applications include disk drives, switching power supplies, DC-DC converters, freewheeling diodes for motor drives, and low-voltage OR-ing / battery protection circuits where low forward drop directly improves efficiency. When designing with this part, verify that the application's reverse voltage never exceeds 15 V repetitive or 25 V non-repetitive, and derate the forward current aggressively above 105 °C board temperature. Solder the cathode tab to a copper pad sized to absorb the conduction loss. This page synthesizes distributor pricing, drop-in alternatives, and practical thermal guidance not consolidated in the manufacturer datasheet.
VS-MBRS320TRPBF - 3A 20V Schottky Rectifier DO-214AA | Vishay
The Vishay VS-MBRS320TRPBF is a 3.0 A surface-mount Schottky rectifier with a 20 V repetitive peak reverse voltage (VRRM) housed in a DO-214AA (SMB) package. The device is optimized for low forward-voltage-drop rectification, with a maximum forward voltage of 0.36 V at 3 A and a typical operating junction temperature range that supports demanding power-supply, freewheeling, and polarity-protection designs. A Schottky rectifier is a majority-carrier diode built from a metal-semiconductor junction rather than a PN junction. This construction eliminates minority-carrier storage charge, so the device switches almost instantaneously with no reverse-recovery time. As a result, Schottky rectifiers are preferred over standard recovery rectifiers in high-frequency switch-mode power supplies, where switching losses and reverse-recovery transients directly erode efficiency. The MBRS320 family sits within Vishay's broader discrete-semiconductor Schottky portfolio aimed at compact, surface-mount power conversion. Key electrical characteristics include a 3.0 A average rectified forward current, 0.36 V maximum forward voltage at rated current, low reverse leakage, and a wide operating junction temperature range suitable for thermally constrained layouts. The SMB (DO-214AA) outline provides an exposed metal pad that doubles as the cathode terminal, enabling low-resistance PCB soldering and direct thermal conduction into the copper land. The tape-and-reel (TRPBF) suffix indicates Pb-free, RoHS-compliant packaging on a 7-inch or 13-inch reel ready for high-volume SMT lines. Typical applications include OR-ing diodes in redundant power architectures, freewheeling diodes across inductive loads such as relays and motor windings, switch-mode power-supply secondary-side rectifiers, reverse-polarity protection on DC inputs, and low-voltage DC-DC converters in industrial, automotive, and telecom equipment. Designers select the MBRS320 for its balance of low forward drop, low leakage, and compact surface-mount footprint. When designing with this part, observe the derating curve of average forward current versus temperature. Thermal management via copper land area is critical: the SMB cathode pad must be soldered to a sufficiently large land to keep junction temperature below the maximum rating under full load. Avoid exceeding the VRRM, and pair the rectifier with adequate heat-sinking where continuous high-current operation is expected. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, giving procurement and design engineers a single decision-ready reference for the VS-MBRS320TRPBF.