Microchip Technology KVX2801-23-4/TR

Overview

KVX2801-23-4/TR from Microsemi is a surface-mount hyperabrupt varactor diode in SOT-23 package, designed for voltage-controlled oscillator (VCO) tuning in VHF–UHF wireless systems. It features a minimum breakdown voltage of 22 V, capacitance of 100–120 pF at 4 V, 39–55 pF at 8 V, and 15–19 pF at 20 V, with Q ≥ 80 at 50 MHz and 4 V reverse bias - enabling wide-octave linear frequency sweep in compact RF front-ends.

For engineers reviewing the KVX2801-23-4/TR datasheet, KVX2801-23-4/TR pinout, KVX2801-23-4/TR application, or KVX2801-23-4/TR equivalent, key selection criteria include tuning ratio (C_4V/C_20V ≈ 5.3–6.7), low thermal coefficient (300 ppm/°C), RoHS-compliant matte tin terminations, and SOT-23 tape-and-reel packaging for automated assembly.

Technical Context

This device belongs to the KVX2xxx series of silicon mesa-geometry hyperabrupt varactors fabricated using high-energy ion implantation and epitaxial junction growth. Its C/V curve delivers high linearity across mid-voltage ranges (4–20 V), supporting straight-line frequency-vs-voltage behavior in VCOs.

The 23-4 configuration denotes a single-diode, anode-to-cathode orientation with cathode connected to pin 1 (SOT-23 standard pinout), optimized for back-to-back pairing in phase shifter or voltage-variable filter applications requiring higher peak voltage handling and lower distortion.

Key Specifications

Pinout & Package

Package: SOT-23 (JEDEC TO-236AB), plastic surface-mount, RoHS-compliant matte tin terminations, supplied on tape-and-reel (TR).

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, KVX2801-23-4/TR uniquely balances wide tuning ratio (>5.3×), robust 22 V rating, and SOT-23/23-4 compatibility - making it optimal for cost-sensitive, wideband VCOs where both linearity and ruggedness are required.

Availability

KVX2801-23-4/TR is available at Aetrix Electronics and suitable for VHF/UHF radio transceivers, PLL frequency synthesizers, voltage-variable filters, and RF phase shifters requiring stable component supply across industrial and communications product lifecycles.

Supply support for KVX2801-23-4/TR 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.

KVX2801-23-4/TR belongs to Microsemi's Microwave Products varactor diode family, engineered specifically for wideband, linear VCO and tunable filter applications demanding repeatable C/V characteristics and high Q in compact SOT-23 form factor.

FAQ

What is the maximum recommended reverse bias voltage for KVX2801-23-4/TR?

The absolute maximum working voltage for KVX2801-23-4/TR is 22 V, specified at 25°C with IR = 10 µA. Operation above 17.6 V (80% of VR) increases leakage risk; sustained bias beyond 22 V may cause irreversible junction breakdown. For reliable VCO design, keep tuning voltage ≤16 V to maintain linearity and longevity.

Does KVX2801-23-4/TR support back-to-back configuration for phase shifter use?

Yes - KVX2801-23-4/TR uses configuration 23-4, which is a single-diode variant with defined anode/cathode orientation (pin 1 = cathode, pin 2 = anode, pin 3 = NC). Two units can be mounted in anti-parallel (cathode-to-cathode) to form a symmetrical voltage-variable capacitor pair, enabling balanced phase shifting up to ±10 V differential swing without DC blocking capacitors.

What is the typical capacitance tolerance at 4 V for KVX2801-23-4/TR?

KVX2801-23-4/TR has a guaranteed capacitance range of 100–120 pF at 4 V reverse bias, measured at 1 MHz. This ±10% spread reflects process-controlled hyperabrupt junction uniformity. For precision VCO calibration, system-level trimming or DAC-based compensation is recommended to accommodate unit-to-unit variation within this band.

Is KVX2801-23-4/TR RoHS compliant and lead-free?

Yes - KVX2801-23-4/TR is RoHS compliant per EU Directive 2002/95/EC and features matte tin terminations suitable for lead-free reflow soldering (J-STD-020 moisture sensitivity level 1). No lead or restricted substances are used in die attach, molding compound, or plating, and full compliance documentation is available upon request.

How does the Q factor of KVX2801-23-4/TR affect phase noise in VCO designs?

KVX2801-23-4/TR's Q ≥ 80 at 50 MHz and 4 V directly limits tank circuit losses: higher Q yields lower Leeson-phase noise floor. In a 400 MHz VCO, using KVX2801-23-4/TR instead of a Q = 40 varactor improves integrated phase noise by ~3 dB in the 10 kHz–1 MHz offset range - critical for meeting ETSI spectral mask requirements in licensed-band radios.