Diodes Incorporated ZC830ATC

Overview

ZC830ATC from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled frequency tuning in precision oscillators and RF filters. It delivers 10.0 pF nominal capacitance at 2 V, 4.5–6.0 capacitance ratio (C₂/C₂₀), Q ≥ 300 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 ZC830ATC datasheet, ZC830ATC pinout, ZC830ATC application, or ZC830ATC equivalent, this device is selected for its tightly controlled CV slope, high Q at RF frequencies, minimal temperature coefficient (300–400 ppm/°C), and SOT23 surface-mount compatibility-critical for stable tuning in compact RF modules and timing circuits.

Technical Context

The ZC830ATC employs a hyperabrupt junction profile to achieve steep, linearized C–V response across 2–20 V, supporting precise frequency pulling in oscillator control loops. Its 25 V reverse breakdown rating and <20 nA leakage at 20 V ensure robust bias stability under varying thermal and supply conditions.

Designed for RF tuning applications, it operates with minimal parasitic series resistance and exhibits predictable capacitance variation over −55°C to +150°C, making it suitable for industrial-grade TCXOs where CV linearity and phase noise floor are design-critical parameters.

Key Specifications

Pinout & Package

Supplied in SOT23 package (JEDEC TO-236AB), with cathode-marked anode-cathode configuration. Standard pin assignment: Pin 1 = Anode, Pin 2 = Cathode, Pin 3 = Cathode (common-cathode dual variant not applicable to ZC830ATC; single-diode configuration).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMV1232-011LF and BBY52-02W, ZC830ATC offers balanced C₂/C₂₀ and Q for mid-range VCXO designs, while its SOT23 mechanical robustness supports reflow reliability in high-volume RF module assembly-making it optimal for cost-sensitive, production-grade timing solutions.

Availability

ZC830ATC is available at Aetrix Electronics and suitable for VCXO design, RF filter tuning, and TCXO temperature compensation requiring stable component supply across industrial, telecom, and mobile radio programs.

Supply support for ZC830ATC 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) was a UK-based ISO 9001/TS16949-certified designer of high-performance analog and RF semiconductors, specializing in precision discrete components for timing, signal conditioning, and power management.

The 830 series varactors were developed specifically for high-stability frequency control in communication oscillators and filters, targeting low-phase-noise performance and tight CV matching in miniature surface-mount formats.

FAQ

What is the maximum recommended reverse voltage for continuous operation?

The ZC830ATC has a rated reverse breakdown voltage of 25 V minimum, but for reliable long-term operation, Zetex specifies a maximum continuous reverse voltage of 20 V. Operating above 20 V risks accelerated parametric drift and increased leakage current, particularly at elevated temperatures (>85°C). Derating to 15 V is advised for mission-critical TCXO applications.

Does ZC830ATC require special PCB layout considerations for RF performance?

Yes. To preserve Q and minimize parasitic inductance, the SOT23 pads must be kept short (<1 mm trace length), use direct ground vias adjacent to the cathode pad, and avoid solder mask over the RF path. Zetex recommends a 0.3 mm thermal relief on cathode pad and no copper pour under the device body to prevent capacitance modulation by nearby traces.

How does temperature affect capacitance tuning linearity?

Capacitance varies with temperature at 300–400 ppm/°C, causing a predictable shift in resonant frequency. While the C–V curve remains monotonic, the slope (dC/dV) decreases ~0.15%/°C, meaning a fixed 0–3 V tuning range yields ~12% less frequency deviation at +100°C versus 25°C. This must be compensated in TCXO analog networks or digital calibration algorithms.

Is ZC830ATC RoHS compliant and halogen-free?

Yes. Per Zetex's 2007 Green Compliance statement, ZC830ATC meets EU RoHS Directive 2002/95/EC requirements and contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE. It is also halogen-free per IEC 61249-2-21, with chlorine and bromine content <900 ppm each, verified through material declaration and supplier testing.