Diodes Incorporated ZMV932TA

Overview

ZMV932TA from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled oscillator (VCO) and temperature-compensated crystal oscillator (TCXO) tuning circuits. It delivers 17.0 pF capacitance at 1 V, 10.5 pF at 4 V, and minimum Q of 200 at 50 MHz, with reverse leakage as low as 200 pA at 8 V - enabling ultra-low phase noise in RF frequency synthesis applications.

For engineers reviewing the ZMV932TA datasheet, ZMV932TA pinout, ZMV932TA application, or ZMV932TA equivalent, key selection criteria include its octave-tuning range (0–6 V), tight C-V tolerance, SOT23 package compatibility, and verified performance in VCXO loop filters and mobile radio front-end VCOs.

Technical Context

This hyperabrupt junction varactor exhibits a steep, linearized C–V slope over 0–6 V, supporting wideband frequency pulling in oscillator control loops. Its 12 V reverse breakdown rating and <100 nA leakage at 8 V ensure stable biasing and minimal tuning drift under thermal variation.

The device operates with a temperature coefficient of capacitance of +300 to +400 ppm/°C at 3 V and 1 MHz, enabling predictable compensation in TCXO designs. Its high Q (>200 at 4 V/50 MHz) directly reduces oscillator phase noise floor by minimizing resonator loss.

Key Specifications

Pinout & Package

SOT23-3 surface-mount package with gull-wing leads; cathode marked by beveled edge or bar on top surface. Thermal pad not present; power dissipation rated at 330 mW at 25°C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMV1232-011 and BBY52-02W, ZMV932TA offers the optimal balance of octave tuning, SOT23 compatibility, and proven TCXO/VCXO linearity - making it the default choice for cost-sensitive, production-ready oscillator designs requiring both range and stability.

Availability

ZMV932TA is available at Aetrix Electronics and suitable for VCXO modules, mobile radio transceivers, TCXO-based timing systems, and pager receiver local oscillators requiring stable component supply across extended product lifecycles.

Supply support for ZMV932TA 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 (now part of Diodes Incorporated) was a UK-based designer of high-performance analog and RF semiconductors, focused on precision discrete components for signal integrity and timing applications.

ZMV932TA belongs to the ZMV93x hyperabrupt varactor family, engineered specifically for low-phase-noise frequency control in compact wireless infrastructure and portable communication equipment.

FAQ

What is the maximum recommended reverse voltage for continuous operation?

The absolute maximum reverse voltage is 12 V, but for reliable long-term operation in VCXO/TCXO circuits, Zetex specifies 8 V as the maximum applied reverse bias. Operating above 8 V increases leakage current exponentially and accelerates parametric drift, especially at elevated temperatures.

Can ZMV932TA be used in series or parallel configurations?

Yes - ZMV932TA supports both configurations. In series, total capacitance decreases and voltage rating increases; in parallel, capacitance sums and Q degrades slightly due to inter-lead inductance. Dual common-cathode variants (e.g., ZMV932TAA) exist for matched-pair applications requiring identical C–V tracking.

How does temperature affect its tuning linearity?

Capacitance vs. voltage linearity remains consistent across -40°C to +85°C, but the absolute C value shifts predictably per its +350 ppm/°C tempco. For TCXO use, this shift is compensated using a thermistor network or digital lookup table calibrated to the measured C–V curve at multiple temperatures.

Is the SOT23 package RoHS-compliant and lead-free?

Yes - ZMV932TA manufactured under Issue 7 (September 2004) and later revisions complies with RoHS Directive 2002/95/EC. The SOT23 package uses matte tin (Sn) lead finish with no lead content, and all internal materials meet JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1) requirements.