Microchip Technology KVX2801-23-4

Overview

KVX2801-23-4 from Microsemi is a 20 V hyperabrupt varactor diode in SOT-23 package, optimized for wideband VCOs up to 1500 MHz. It delivers a capacitance tuning range of 39–55 pF at 4 V, 18–25 pF at 8 V, and 7.3–9.2 pF at 20 V, with minimum Q = 125 at 50 MHz/4 V, enabling high-linearity frequency synthesis in wireless transceivers.

For engineers reviewing the KVX2801-23-4 datasheet, KVX2801-23-4 pinout, KVX2801-23-4 application, or KVX2801-23-4 equivalent, key selection criteria include its 22 V maximum working voltage, hyperabrupt junction profile for straight-line C/V response, SOT-23 footprint compatibility, and suitability for PLL-based VCOs requiring octave bandwidth and low phase noise.

Technical Context

This device uses high-energy ion implantation and grown-junction epitaxy to achieve repeatable hyperabrupt C/V characteristics across its 4–20 V tuning range. Its silicon mesa geometry and dense SiO₂ passivation ensure stable performance from –55°C to +125°C.

The KVX2801-23-4 is configured in Package Style 23-4 (single die, anode-cathode-anode), supporting back-to-back connection for higher peak voltage handling and reduced distortion in voltage-variable filters and phase shifters.

Key Specifications

Pinout & Package

SOT-23 surface-mount package (JEDEC TO-236AB), 3-terminal configuration per Package Style 23-4: two anodes flanking a common cathode (A–K–A).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar varactor diode applications.

Compared with MAVR-000120-1411 and SMV2023-011, the KVX2801-23-4 uniquely supports back-to-back configuration via its 23-4 pinout, enabling higher voltage swing and lower distortion in filter and phase shifter designs-without requiring PCB redesign or additional discrete components.

Availability

KVX2801-23-4 is available at Aetrix Electronics and suitable for VHF/UHF PLL VCOs, octave-bandwidth synthesizers, voltage-variable filters, and low-distortion phase shifters requiring stable component supply across industrial, aerospace, and communications programs.

Supply support for KVX2801-23-4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, RF, and timing solutions for aerospace, defense, and industrial markets.

The KVX2801-23-4 belongs to Microsemi's Microwave Products varactor diode family, engineered specifically for high-linearity, wide-tuning-ratio VCOs and voltage-variable reactive circuits in demanding RF systems.

FAQ

What is the maximum reverse voltage rating for KVX2801-23-4?

The KVX2801-23-4 has a maximum working voltage of 22 V, specified at 25°C with IR = 10 µA. This rating applies to single-diode operation; in back-to-back configuration (using both anodes), the effective voltage handling doubles to 44 V, as confirmed in the factory configuration sheet for Package Style 23-4.

Does KVX2801-23-4 support back-to-back connection, and how is it implemented?

Yes, KVX2801-23-4 supports back-to-back connection using its Package Style 23-4 layout (A–K–A). Pins 1 and 3 serve as independent anodes, while Pin 2 is the shared cathode. This configuration allows symmetric reverse biasing, doubling peak voltage capability and reducing second-harmonic distortion in voltage-variable filters and phase shifters.

What is the capacitance range of KVX2801-23-4 at 4 V and 20 V reverse bias?

Per the official Microsemi electrical parameters table, KVX2801-23-4 exhibits a capacitance range of 39–55 pF at 4 V reverse bias and 7.3–9.2 pF at 20 V reverse bias, measured at 1 MHz. These values define its usable tuning span for VCO and filter applications requiring wide dynamic range.

How does the Q factor of KVX2801-23-4 impact VCO phase noise performance?

The minimum Q of 125 at 50 MHz and 4 V directly limits series resistance in the resonant tank, reducing thermal noise contribution to the oscillator output. In practice, this enables KVX2801-23-4-based VCOs to achieve <–110 dBc/Hz phase noise at 100 kHz offset in 400–900 MHz designs, as validated in Microsemi application notes for PLL VCO implementations.

Is KVX2801-23-4 RoHS compliant, and what is its termination finish?

Yes, KVX2801-23-4 is RoHS compliant per EU Directive 2002/95/EC. It features matte tin terminations, qualified for lead-free reflow soldering processes without solderability degradation or intermetallic compound formation that could compromise long-term joint integrity.