Diodes Incorporated ZC930TC

Overview

ZC930TC from Zetex Semiconductors is a 12 V hyperabrupt silicon varactor diode in SOD323 package, designed for voltage-controlled frequency tuning in oscillator circuits. It delivers 8.7 pF capacitance at 1 V, 4.3 pF at 2.5 V, and 2.9 pF at 4 V reverse bias, with minimum Q of 200 at 50 MHz and typical reverse leakage of 200 pA - enabling low-phase-noise VCXO/TCXO designs for wireless infrastructure.

For engineers reviewing the ZC930TC datasheet, ZC930TC pinout, ZC930TC application, or ZC930TC equivalent, key selection criteria include its hyperabrupt C-V slope (octave tuning from 0–6 V), tight CV tolerance, SOD323 footprint compatibility, and verified performance in temperature-compensated crystal oscillator feedback loops.

Technical Context

The ZC930TC operates as a voltage-variable capacitor whose junction capacitance decreases nonlinearly with increasing reverse bias - optimized via hyperabrupt doping profile to achieve octave-range frequency tuning (e.g., 2× frequency ratio) across 0–6 V. Its low 200 pA IR minimizes thermal noise injection into resonant tank circuits.

Designed for integration into Pierce or Clapp oscillator topologies, it pairs with quartz crystals in TCXO/VCXO modules where phase noise ≤ –150 dBc/Hz at 10 kHz offset is required. The SOD323 package supports high-frequency layout integrity with minimal parasitic inductance (<0.3 nH) and capacitance (<0.05 pF).

Key Specifications

Pinout & Package

SOD323 surface-mount package: cathode-marked rectangular body (2.67–3.05 mm L × 1.20–1.40 mm W × 0.33–0.51 mm H), with gull-wing leads on 0.95 mm pitch. Cathode identified by beveled edge or bar marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMV1233-011LF and BBY40-02W, the ZC930TC offers optimal balance of tuning ratio, Q, and leakage for 10–30 MHz TCXO applications - delivering lower phase noise than BBY40-02W and better CV linearity than SMV1233-011LF in industrial temperature ranges.

Availability

ZC930TC is available at Aetrix Electronics and suitable for VCXO design, TCXO manufacturing, and RF front-end filter tuning requiring stable component supply across automotive infotainment, industrial telemetry, and legacy wireless infrastructure programs.

Supply support for ZC930TC 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 Diodes Incorporated) specialized in high-performance analog and RF discrete semiconductors, with focus on low-noise, high-Q passive and active devices for timing and signal conditioning.

The ZC930TC belongs to Zetex's hyperabrupt varactor series engineered specifically for precision frequency control in temperature-stable oscillators - emphasizing CV repeatability, ultra-low leakage, and SMT manufacturability.

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 TCXO circuits, Zetex specifies 8 V as the maximum recommended DC bias. At 8 V, reverse leakage remains ≤100 nA and capacitance change stabilizes within ±0.5% over 1,000 hours at 85°C ambient.

Does ZC930TC support reflow soldering per JEDEC J-STD-020C?

Yes - the SOD323 package is qualified for lead-free reflow per J-STD-020C, with peak temperature up to 260°C for ≤30 seconds. Thermal resistance from junction-to-case is 220°C/W, and board-level thermal relief pads are recommended to avoid solder joint cracking during thermal cycling.

How does temperature affect capacitance tuning linearity?

At VR = 3 V, the temperature coefficient of capacitance is 300–400 ppm/°C, causing ~0.3% capacitance shift over –40°C to +85°C. This introduces predictable curvature in C-V curves, which TCXO compensation circuits explicitly model using quadratic coefficients in their DAC lookup tables.

Can ZC930TC be used in series with another varactor for extended tuning range?

No - the ZC930TC is not characterized for series connection. Its hyperabrupt profile assumes single-diode operation; cascading alters effective C-V exponent and degrades Q due to added series resistance. Zetex recommends ZC933TA (42 pF @ 1 V) instead for wider-range applications.