Diodes Incorporated ZMV831BTA

Overview

ZMV831BTA from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled frequency tuning in precision oscillators, with 15.0 pF nominal capacitance at 2 V, 300 minimum Q at 50 MHz, and 4.5–6.0 capacitance ratio (C₂/C₂₀). It operates up to 25 V reverse bias, exhibits ultra-low 200 pA typical reverse leakage, and is packaged in SOT23 for surface-mount RF filtering and VCXO/TCXO applications.

For engineers reviewing the ZMV831BTA datasheet, ZMV831BTA pinout, ZMV831BTA application, or ZMV831BTA equivalent, key selection criteria include its hyperabrupt CV slope for steep tuning response, low phase noise contribution due to minimal IR, high Q at RF frequencies, and compatibility with miniature SMT layouts requiring stable C-V linearity across 2–20 V.

Technical Context

ZMV831BTA is a single-junction, N-type silicon hyperabrupt varactor designed for analog voltage-to-capacitance conversion in closed-loop frequency control systems. Its doping profile delivers a steeper C–V slope than abrupt junctions, enabling tighter frequency resolution in VCXOs and improved filter tracking in tunable RF front-ends.

The device functions exclusively under reverse bias, with capacitance varying from ~15.75 pF at 2 V to ~2.63 pF at 20 V (calculated from C₂/C₂₀ ≥ 4.5), and maintains low temperature coefficient (300–400 ppm/°C) to minimize drift in temperature-sensitive timing circuits.

Key Specifications

Pinout & Package

Package: SOT23 - 3-pin, surface-mount plastic package with cathode-marked lead (Pin 1), anode (Pin 2), and cathode (Pin 3) in common-cathode dual configuration; footprint compatible with JEDEC TO-236AB standard, 2.9 mm × 1.3 mm × 1.0 mm body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMV2019-011LF and BBY52-02W, ZMV831BTA offers superior C–V linearity and lowest leakage for precision oscillator applications, trading off maximum tuning range and unit cost for phase noise integrity in telecom-grade timing.

Availability

ZMV831BTA is available at Aetrix Electronics and suitable for VCXO design, TCXO calibration, and wireless IF filtering requiring stable component supply with guaranteed traceability and RoHS-compliant manufacturing.

Supply support for ZMV831BTA 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

Zetex Semiconductors plc was a UK-based ISO 9001 and TS16949-certified manufacturer specializing in high-performance analog and RF discrete semiconductors before its acquisition by Diodes Incorporated in 2008.

ZMV831BTA belongs to the 830-series hyperabrupt varactor family, engineered specifically for low-phase-noise frequency control in communications infrastructure and portable radio equipment where CV slope and Q factor directly impact spectral purity.

FAQ

What is the maximum recommended reverse voltage for continuous operation of ZMV831BTA?

The absolute maximum reverse voltage is 25 V, but for reliable long-term operation in VCXO applications, Zetex recommends limiting bias to ≤20 V to maintain C–V stability and avoid accelerated aging. Derating to 15 V is advised for designs requiring >10-year field life at 85°C ambient.

Does ZMV831BTA have a specified junction temperature limit?

ZMV831BTA has no separate junction temperature rating; its safe operating area is defined by power dissipation limits. At 25°C ambient, max power is 330 mW in SOT23. With typical IR <20 nA at 20 V, self-heating is negligible (<0.4°C rise), so thermal design focuses on PCB copper area and ambient derating above 70°C.

Is ZMV831BTA suitable for use in DC-coupled tuning circuits?

No-ZMV831BTA must operate under reverse bias only. DC coupling risks forward conduction if voltage polarity reverses, causing irreversible junction damage. Always use series DC-blocking capacitors and ensure bias network provides unidirectional reverse voltage with adequate ripple suppression.

How does the SOT23 package affect RF performance compared to SOD323?

SOT23 offers lower series inductance (~0.6 nH) than SOD323 (~0.9 nH) due to shorter leads and larger pad area, improving high-frequency Q above 50 MHz. However, SOD323 provides better thermal resistance for high-bias applications-SOT23 is preferred for VCXOs, SOD323 for high-power VCOs.