Diodes Incorporated ZMV834BTA

Overview

ZMV834BTA from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled frequency tuning in precision oscillators and RF filters. It delivers 44.65–49.35 pF capacitance at 2 V, 5.0–6.5 capacitance ratio (C₂/C₂₀), ≥200 Q at 50 MHz, <20 nA reverse leakage at 20 V, and ±300–400 ppm/°C temperature coefficient - enabling low-phase-noise VCXO designs in wireless infrastructure.

For engineers reviewing the ZMV834BTA datasheet, ZMV834BTA pinout, ZMV834BTA application, or ZMV834BTA equivalent, key selection criteria include its SOT23 package compatibility, hyperabrupt CV slope for steep tuning response, high Q at VHF/UHF, tight capacitance tolerance (±5%), and suitability for TCXO/VCXO calibration loops requiring stable C-V linearity over temperature.

Technical Context

ZMV834BTA operates as a voltage-dependent capacitor with hyperabrupt doping profile, engineered to produce a steeper C–V slope than standard abrupt junction varactors. Its capacitance varies from ~47 pF at 2 V to ~14 pF at 20 V, yielding a nominal C₂/C₂₀ ratio of 5.5 - critical for wide-tuning-range oscillator designs where linear frequency vs. control voltage is required.

The device exhibits low series resistance and high Q (>200 at 50 MHz), minimizing insertion loss and phase noise degradation in resonant tank circuits. Its 25 V reverse breakdown rating and <20 nA IR at 20 V support robust operation in battery-powered and low-power RF modules without bias drift or thermal runaway risk.

Key Specifications

Pinout & Package

Supplied in SOT23 package: three-terminal surface-mount case with anode, cathode, and case (cathode-connected substrate). Cathode marked by molded notch or bar; pin 1 = anode, pin 2 = cathode, pin 3 = case (common cathode configuration).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMV2023-011LF and BBY58-02W, ZMV834BTA offers the best trade-off of mid-band capacitance, hyperabrupt slope, and Q for sub-2 GHz VCXO designs - especially where ±5 ppm stability over temperature and low control-voltage leakage are mandatory.

Availability

ZMV834BTA is available at Aetrix Electronics and suitable for VCXO calibration, UHF filter tuning, mobile radio LO generation, and GPS L1 VCO designs requiring stable component supply, consistent CV matching, and RoHS-compliant SMT packaging.

Supply support for ZMV834BTA 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 (now part of Diodes Incorporated) was a UK-based ISO 9001/TS16949-certified designer of high-performance analog and RF semiconductors, specializing in discrete power and signal-conditioning components.

ZMV834BTA belongs to the 830-series hyperabrupt varactor family, developed specifically for precision frequency control in telecom timing modules, wireless transceivers, and instrumentation-grade oscillators demanding tight CV tolerance and low phase noise.

FAQ

What is the maximum reverse voltage rating for ZMV834BTA?

ZMV834BTA has a guaranteed minimum reverse breakdown voltage of 25 V at 10 μA test current. Operation above 20 V is not recommended due to increased leakage and accelerated degradation; typical design practice limits VR to ≤15 V for long-term reliability in continuous tuning applications.

Does ZMV834BTA require derating at elevated temperatures?

Yes - reverse leakage current increases exponentially with temperature; at +125°C, IR may reach 200 nA (vs. <20 nA at 25°C), potentially affecting control-voltage stability in closed-loop systems. Derate maximum VR by 0.1 V/°C above 25°C to maintain leakage below 50 nA in high-temp TCXO designs.

Can ZMV834BTA be used in dual-common-cathode configurations?

No - ZMV834BTA is a single-junction varactor in SOT23 package. Dual variants (e.g., ZMDC834BTA) exist in SOD-323 but are distinct order codes; mixing packages or configurations risks incorrect biasing and thermal mismatch in multi-varactor tanks.

Is ZMV834BTA lead-free and RoHS compliant?

Yes - per Zetex's Green Compliance statement (Issue 11, Jan 2007), all 830-series devices including ZMV834BTA meet EU RoHS Directive 2002/95/EC requirements, with lead content <1000 ppm and no intentionally added cadmium, mercury, hexavalent chromium, PBB, or PBDE.