Diodes Incorporated ZMV834ATA

Overview

ZMV834ATA from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled frequency tuning in precision oscillators and RF filters. It delivers 47.0 pF nominal capacitance at 2 V, 5.0–6.5 capacitance ratio (C₂/C₂₀), ≥200 Q at 50 MHz, and ultra-low reverse leakage (200 pA typ.), enabling low-phase-noise VCXO/TCXO designs in wireless infrastructure.

For engineers reviewing the ZMV834ATA datasheet, ZMV834ATA pinout, ZMV834ATA application, or ZMV834ATA equivalent, key selection criteria include its 25 V reverse breakdown rating, SOT23 package compatibility, hyperabrupt CV slope for steep tuning response, and suitability for high-stability reference clock generation in mobile radio and pager systems.

Technical Context

ZMV834ATA operates as a voltage-variable capacitor whose junction capacitance varies nonlinearly with applied reverse bias-specifically engineered with hyperabrupt doping profile to yield steeper dC/dV slope than abrupt junctions. This enables finer frequency resolution and improved linearity in VCO control loops.

Its 25 V maximum reverse voltage rating and −55°C to +150°C operating range support robust operation in temperature-sensitive RF front-ends. The 300–400 ppm/°C temperature coefficient of capacitance is tightly controlled to minimize drift-induced frequency error in oscillator tanks.

Key Specifications

Pinout & Package

Supplied in SOT23 surface-mount package (JEDEC TO-236AB), with cathode-marked lead configuration. Thermal resistance θ_JA = 250°C/W enables stable operation at ≤200 mA forward current without derating in standard PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMV2019-011LF and BBY58-02W, ZMV834ATA provides optimal balance of mid-band capacitance (47 pF), wide tuning ratio (5.0–6.5), and 25 V ruggedness-making it preferred for 400–900 MHz VCXO/TCXO designs requiring both stability and tuning range.

Availability

ZMV834ATA is available at Aetrix Electronics and suitable for wireless communications infrastructure, mobile radio transceivers, and pager frequency synthesizers requiring stable component supply with consistent CV matching across production lots.

Supply support for ZMV834ATA 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/TS16949-certified manufacturer specializing in high-performance analog and RF discrete semiconductors before its acquisition by Diodes Incorporated in 2008.

ZMV834ATA belongs to the 830 series hyperabrupt varactor family, designed specifically for low-phase-noise frequency control in portable and infrastructure wireless equipment where tight CV tolerance and high Q are mandatory.

FAQ

What is the recommended PCB pad layout for ZMV834ATA in SOT23?

Use JEDEC-standard SOT23 footprint with 0.95 mm pad length, 0.65 mm pad width, and 0.95 mm center-to-center spacing. Maintain ≤0.3 mm solder mask opening beyond copper to prevent bridging. Ground plane under the device must be removed within 0.5 mm of pins 1 and 2 to minimize parasitic capacitance to substrate.

Can ZMV834ATA be used in series-tuned VCO configurations?

No-ZMV834ATA is specified and characterized only for shunt-connected (parallel-tuned) oscillator topologies such as Pierce and Colpitts. Its hyperabrupt profile and Q factor are optimized for parallel resonance; series resonance use would degrade tuning linearity and increase phase noise due to unmodeled series resistance effects.

Does ZMV834ATA require derating at elevated ambient temperatures?

Yes-maximum reverse voltage must be reduced linearly above 25°C: VR(max) = 25 V − 0.05 V/°C × (T_A − 25°C). At 100°C ambient, rated reverse voltage drops to 21.25 V. Derating ensures junction temperature remains below 150°C given its 250°C/W θ_JA and typical power dissipation <1 mW in tuned circuits.

Is ZMV834ATA RoHS-compliant and halogen-free?

Yes-ZMV834ATA conforms to EU RoHS Directive 2011/65/EU and is manufactured with halogen-free molding compound. Certificate of Compliance (CoC) and material declarations are available upon request from Aetrix Electronics for full WEEE/ELV alignment in end-product certification.