Diodes Incorporated ZMV831ATC

Overview

ZMV831ATC from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled frequency tuning in precision oscillators and RF filters. It delivers 15.0 pF nominal capacitance at 2 V, 4.5–6.0 capacitance ratio (C₂/C₂₀), ≥300 Q at 50 MHz, and ultra-low reverse leakage (200 pA typ.), enabling low-phase-noise VCXO/TCXO designs in wireless infrastructure and mobile radio front-ends.

For engineers reviewing the ZMV831ATC datasheet, ZMV831ATC pinout, ZMV831ATC application, or ZMV831ATC equivalent, key selection criteria include its hyperabrupt CV slope for steep tuning response, SOT23 package compatibility with high-density RF layouts, guaranteed C₂/C₂₀ ≥4.5, and −55°C to +150°C operating range for industrial-grade stability.

Technical Context

The ZMV831ATC employs a hyperabrupt junction profile engineered to produce a steep, linearized voltage-to-capacitance transfer function-critical for minimizing tuning nonlinearity in voltage-controlled crystal oscillators. Its 25 V reverse breakdown rating and 200 pA max IR at 20 V ensure robust bias margin and minimal phase noise contribution in closed-loop PLL systems.

Designed for RF impedance matching and band-select filtering, it operates with stable CV characteristics across −55°C to +150°C, supported by a temperature coefficient of capacitance of 300–400 ppm/°C. The device's high Q (>300 @ 50 MHz) directly reduces resonator insertion loss and improves oscillator short-term stability.

Key Specifications

Pinout & Package

Supplied in SOT23 package (JEDEC TO-236AB), 3-terminal surface-mount configuration with anode, cathode, and case (cathode-connected substrate). Dimensions: 2.67–3.05 mm × 1.20–1.40 mm × 0.95 mm height.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMV2023-011LF and BBY52-02W, ZMV831ATC offers balanced trade-offs: sufficient Q and tuning ratio for VCXO use, industry-standard SOT23 compatibility, and proven low-leakage performance at moderate cost-making it optimal for volume RF timing and filtering designs.

Availability

ZMV831ATC is available at Aetrix Electronics and suitable for VCXO design, TCXO compensation networks, and RF band-select filtering requiring stable component supply across automotive infotainment, industrial wireless sensors, and 4G/LTE small-cell base stations.

Supply support for ZMV831ATC 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) is a UK-based designer and manufacturer of high-performance analog and discrete semiconductors, ISO 9001 and TS16949 certified.

The 830 series varactors were developed specifically for precision frequency control in communications infrastructure, emphasizing hyperabrupt CV linearity, low phase noise, and wide-temperature reliability in compact SMT packages.

FAQ

What is the maximum recommended reverse voltage for continuous operation?

The ZMV831ATC has a minimum reverse breakdown voltage of 25 V and is rated for continuous reverse bias up to 20 V per absolute maximum ratings. Operating above 20 V risks irreversible junction degradation and increased leakage; derating to ≤15 V is advised for long-term reliability in temperature-cycled environments.

Does ZMV831ATC require special PCB layout considerations for RF performance?

Yes-its high Q depends on minimizing parasitic inductance and capacitance. Use short, direct traces to RF ground, avoid vias in cathode/anode paths, and place the device adjacent to the crystal or filter inductor. A solid ground plane under the SOT23 pad (Pin 3) is mandatory to preserve Q and thermal stability.

How does the 300–400 ppm/°C temperature coefficient affect TCXO design?

This TCC allows direct analog cancellation of AT-cut quartz crystal drift (typically −20 to −30 ppm/°C over 0–70°C) when used in series with thermistors or DAC-driven networks. Its predictable, monotonic slope enables first-order compensation without iterative calibration, reducing TCXO manufacturing test time.

Is ZMV831ATC RoHS compliant and lead-free?

Yes-Zetex confirmed full compliance with the EU RoHS Directive (2011/65/EU) in Issue 11 of the 830 series datasheet. The device uses lead-free matte tin plating on SOT23 terminations and contains no restricted substances above threshold limits, supporting WEEE and ELV directive alignment.