Diodes Incorporated ZMV934ATC

Overview

ZMV934ATC from Zetex Semiconductors is a 12 V hyperabrupt silicon varactor diode optimized for voltage-controlled oscillator (VCO) and temperature-compensated crystal oscillator (TCXO) tuning circuits. It delivers 95.0 pF capacitance at 1 V, 40.0 pF at 2.5 V, and 25.0 pF at 4 V reverse bias, with minimum Q of 80 at 50 MHz and typical reverse leakage of 200 pA - enabling ultra-low phase noise in wireless transceivers and mobile radio front-ends.

For engineers reviewing the ZMV934ATC datasheet, ZMV934ATC pinout, ZMV934ATC application, or ZMV934ATC equivalent, key selection criteria include its octave-tuning range (0–6 V), hyperabrupt C-V slope (300–400 ppm/°C), SOD323 package footprint, and verified performance in VCXO loop filters requiring high Q and tight CV tolerance.

Technical Context

This varactor operates as a voltage-dependent capacitor in RF tuning networks, where its hyperabrupt junction profile ensures linearized frequency vs. control voltage response. Its low IR (≤100 nA at VR = 8 V) and tightly controlled capacitance tolerance directly suppress FM noise sidebands in oscillator phase-locked loops.

The device is characterized at 25°C with specified C-V curves across 1–4 V, and absolute maximum ratings include 12 V reverse breakdown and 330 mW power dissipation in SOD323 package - defining safe operating limits for continuous bias in compact RF modules.

Key Specifications

Pinout & Package

SOD323 surface-mount package: cathode-marked, 2-terminal device with anode (pin 1) and cathode (pin 2) aligned to JEDEC standard orientation; body dimensions 1.25 mm × 0.85 mm × 0.55 mm (max height).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMV1232-011LF and BBY58-02W, ZMV934ATC uniquely balances wide tuning ratio (3.8:1), moderate Q (80), and tight CV tolerance - making it optimal for cost-sensitive, octave-spanning TCXO/VCXO designs below 1.5 GHz where 12 V compliance suffices.

Availability

ZMV934ATC is available at Aetrix Electronics and suitable for VCXO design, TCXO manufacturing, and mobile radio transceiver development requiring stable component supply, consistent C-V matching, and RoHS-compliant SOD323 packaging.

Supply support for ZMV934ATC 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) specialized in high-performance discrete semiconductors for RF, power management, and precision analog applications.

The ZMV930 series was engineered specifically for frequency control systems demanding low-phase-noise tuning elements with reproducible hyperabrupt characteristics in miniature packages.

FAQ

What is the recommended PCB pad layout for ZMV934ATC in SOD323?

Use IPC-7351B compliant pads: 0.9 mm × 0.6 mm copper lands with 0.2 mm solder mask opening, spaced 0.7 mm center-to-center. Thermal relief vias are discouraged beneath the cathode pad to avoid parasitic capacitance shifts above 500 MHz.

Can ZMV934ATC be used in series or parallel configurations for extended tuning range?

Parallel connection of two ZMV934ATC units doubles capacitance but halves effective Q and increases leakage current; series connection halves capacitance but preserves Q. Neither configuration is characterized in the datasheet, and mismatched C-V curves may cause nonlinearity - single-device use is validated.

Does ZMV934ATC require derating at elevated ambient temperatures?

Yes: maximum reverse voltage must be reduced by 0.08 V/°C above 25°C ambient. At 85°C, max VR drops to 7.2 V. Power dissipation remains limited to 330 mW only at Tamb ≤ 25°C; thermal resistance θ_JA = 300°C/W requires board-level copper area for safe operation.

Is the temperature coefficient of capacitance (TCC) stable across the full 0–6 V tuning range?

No - TCC varies from 300 ppm/°C at VR = 1 V to 400 ppm/°C at VR = 4 V, as confirmed by Figure 5 in Issue 7 datasheet. This voltage-dependent drift is inherent to hyperabrupt junctions and must be modeled in TCXO compensation algorithms.