Diodes Incorporated ZC833BNTA

Overview

ZC833BNTA from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled frequency tuning in precision oscillators. It delivers 33.0 pF nominal capacitance at 2 V, 5.0–6.5 capacitance ratio (C₂/C₂₀), ≥200 Q 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 ZC833BNTA datasheet, ZC833BNTA pinout, ZC833BNTA application, or ZC833BNTA equivalent, key selection criteria include its SOT23 package compatibility, hyperabrupt CV slope for steep tuning response, guaranteed C₂/C₂₀ ≥5.0, and operation up to 25 V reverse bias with <20 nA leakage at 20 V.

Technical Context

This device operates as a voltage-variable capacitor whose junction capacitance varies nonlinearly with applied reverse bias-specifically engineered with hyperabrupt doping profile to achieve steeper dC/dV than abrupt junctions. Its CV curve is tightly controlled across production lots, ensuring predictable tuning linearity in oscillator feedback networks.

Designed for RF frequency control, it functions exclusively under reverse bias (0–25 V), with no forward conduction intended. The 200 pA typical IR at 2 V minimizes bias-current-induced phase noise, while the 300–400 ppm/°C temperature coefficient of capacitance requires compensation in high-stability timing applications.

Key Specifications

Pinout & Package

Supplied in JEDEC-standard SOT23 package (3-lead, single anode/cathode configuration). Cathode is marked by a band on lead 3; anode is lead 1. Thermal pad not present; power dissipation limited to 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 ZC833ATA and SMV2023-011LF, ZC833BNTA offers the tightest CV matching for production-ready oscillator designs, highest Q for lowest phase noise, and SOT23 thermal robustness-making it optimal for telecom-grade timing modules where yield and stability are critical.

Availability

ZC833BNTA is available at Aetrix Electronics and suitable for VCXO design, TCXO manufacturing, and mobile radio VCO development requiring stable component supply and traceable lot-level CV characterization.

Supply support for ZC833BNTA 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 discrete semiconductors before its acquisition by Diodes Incorporated in 2008.

The 830 series varactors were developed specifically for precision frequency control in wireless infrastructure and portable communications equipment, emphasizing CV repeatability, low leakage, and RF efficiency in miniature packages.

FAQ

What is the maximum recommended reverse voltage for continuous operation?

The absolute maximum reverse voltage is 25 V, but sustained operation above 20 V increases leakage current nonlinearly and accelerates long-term parameter drift. For reliability in 10-year telecom deployments, Zetex specifies derated operation at ≤18 V with 80% confidence across temperature and lifetime.

Does ZC833BNTA require DC blocking in RF signal paths?

No-ZC833BNTA is operated exclusively under reverse bias and presents only capacitive impedance to RF signals. However, a series RF choke or high-value resistor (≥100 kΩ) must isolate the DC tuning voltage from the RF node to prevent signal injection into the control line.

How does the SOT23 package affect RF performance compared to SOD-323?

The SOT23's longer leads increase series inductance (~0.8 nH vs. ~0.3 nH for SOD-323), degrading Q above 500 MHz. At 50 MHz, both packages perform identically; below 200 MHz, SOT23's superior thermal mass improves bias stability during pulsed RF operation.

Can ZC833BNTA be used in forward bias for switching applications?

No-it is not characterized or rated for forward conduction. Forward bias exceeds the 200 mA absolute maximum rating within nanoseconds and causes irreversible junction damage. Its structure is optimized solely for reverse-biased variable capacitance, not rectification or switching.