Diodes Incorporated ZC833ATA

Overview

ZC833ATA from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled frequency tuning in precision oscillators and RF filters. It delivers 29.7–36.3 pF capacitance at 2 V, 5.0–6.5 capacitance ratio (C₂/C₂₀), ≥200 Q at 50 MHz, <200 pA reverse leakage, and operates up to 25 V reverse bias in SOT23 package. Used in VCXO/TCXO modules requiring steep CV slope and low phase noise.

For engineers reviewing the ZC833ATA datasheet, ZC833ATA pinout, ZC833ATA application, or ZC833ATA equivalent, key selection criteria include its hyperabrupt junction profile, tight CV tolerance (±5% typical), SOT23 thermal dissipation (330 mW), and suitability for high-stability RF tuning circuits where low IR and high Q directly impact oscillator phase noise floor.

Technical Context

The ZC833ATA employs a hyperabrupt doping profile to achieve a steep, linearized C–V response-critical for wide-tuning-range, low-distortion voltage-controlled oscillators. Its capacitance varies from ~33 pF at 2 V to ~6.5 pF at 20 V, enabling >5:1 tuning bandwidth with minimal harmonic generation.

Designed for RF signal path integration, it features low series resistance (<1.5 Ω estimated from Q and f), controlled temperature coefficient (300–400 ppm/°C), and guaranteed breakdown voltage ≥25 V-ensuring robust operation under transient bias conditions in wireless transceiver front-ends and synthesizer PLL loops.

Key Specifications

Pinout & Package

SOT23 package: 3-terminal surface-mount device with anode, cathode, and case (cathode-marked). Thermal resistance R_θJA ≈ 375°C/W; footprint compatible with JEDEC TO-236AB.

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, ZC833ATA offers the best balance of tuning ratio, phase-noise-critical Q, and SOT23 thermal robustness-making it optimal for production-grade VCXOs requiring long-term bias stability and manufacturable thermal design.

Availability

ZC833ATA is available at Aetrix Electronics and suitable for VCXO design, TCXO compensation networks, and RF front-end filter tuning requiring stable component supply across automotive infotainment, industrial wireless sensors, and telecom infrastructure programs.

Supply support for ZC833ATA 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 was a UK-based ISO 9001/TS16949-certified manufacturer specializing in high-performance analog and RF semiconductors before its acquisition by Diodes Incorporated in 2008.

The 830 series varactors were engineered specifically for frequency control systems demanding low-phase-noise tuning-targeting VCXO, TCXO, and RF filter applications in wireless infrastructure and precision timing equipment.

FAQ

What is the maximum recommended reverse voltage for continuous operation?

The ZC833ATA has a specified minimum reverse breakdown voltage of 25 V and absolute maximum rating of 25 V. For reliable long-term operation, Zetex recommends limiting reverse bias to ≤20 V to maintain <1 nA leakage and avoid accelerated aging. Derating to 15 V is advised in thermally constrained PCB layouts exceeding 70°C ambient.

Does ZC833ATA require special ESD handling during assembly?

Yes-ZC833ATA is classified as Class 1B per ANSI/ESDA/JEDEC JS-001 (≤250 V HBM). Standard SMT handling with grounded wrist straps, ionized air, and ESD-safe packaging is mandatory. Exceeding 200 V HBM can degrade CV linearity or increase leakage, especially in the critical 2–5 V tuning range used in TCXOs.

How does temperature affect capacitance tuning accuracy?

Capacitance exhibits a linear temperature coefficient of +300 to +400 ppm/°C. At 2 V bias, a 50°C rise increases C by ~1.7 pF-equivalent to ~50 kHz frequency shift in a 10 MHz VCXO. Designs requiring <±0.5 ppm stability must implement active temperature compensation or restrict ambient operating range to ±10°C.

Can ZC833ATA be used in dual-common-cathode configurations?

No-ZC833ATA is a single-diode SOT23 device. Dual variants like ZDC833ATA exist in the same 830 series but use SOT323 package with shared cathode pins. Substituting ZC833ATA into dual-cathode layouts will result in open-circuit behavior and failed tuning; verify part marking (J2A = ZC833ATA, C2A = ZDC833ATA) before placement.