Diodes Incorporated ZMV829BTC

Overview

ZMV829BTC from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled frequency tuning in precision oscillators and RF filters. It delivers 8.2 pF nominal capacitance at 2 V, 4.3–5.8 capacitance ratio (C₂/C₂₀), Q ≥ 250 at 50 MHz, and ultra-low reverse leakage (200 pA typ.), enabling low-phase-noise VCXO/TCXO designs in SOT23 surface-mount packages.

For engineers reviewing the ZMV829BTC datasheet, ZMV829BTC pinout, ZMV829BTC application, or ZMV829BTC equivalent, key selection criteria include its hyperabrupt CV slope, tight ±5% capacitance tolerance (Grade A), 25 V reverse breakdown rating, and compatibility with miniature SOT23 footprint for space-constrained RF front-ends and timing modules.

Technical Context

ZMV829BTC employs a hyperabrupt junction profile to achieve steep, linearized C–V response-critical for wide-tuning-range, low-distortion voltage-controlled oscillators. Its capacitance varies from ~8.2 pF at 2 V to ~1.4 pF at 20 V, supporting high-frequency stability in TCXO reference loops.

The device operates with negligible series resistance and exhibits temperature coefficient of capacitance between +300 and +400 ppm/°C, requiring compensation in oven-controlled or digitally calibrated systems. Reverse leakage remains below 20 nA up to 20 V, preserving oscillator phase noise floor across industrial temperature range (−55°C to +150°C).

Key Specifications

Pinout & Package

Supplied in SOT23 package (JEDEC TO-236AB), with cathode-marked terminal configuration. Standard pinout: Pin 1 = Anode, Pin 2 = Cathode, Pin 3 = Cathode (common-cathode dual variant not applicable to ZMV829BTC; this is a single-diode variant).

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, ZMV829BTC offers the optimal balance of mid-range capacitance (8.2 pF), high tuning ratio (4.3–5.8), and proven industrial reliability in SOT23-making it preferred for cost-sensitive, high-volume TCXO/VCXO manufacturing where ±5% C tolerance and −55°C to +150°C operation are mandatory.

Availability

ZMV829BTC is available at Aetrix Electronics and suitable for VCXO reference oscillators, RF front-end tuning filters, and TCXO compensation networks requiring stable component supply across automotive infotainment, industrial wireless sensors, and telecom infrastructure programs.

Supply support for ZMV829BTC 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 designer and manufacturer of high-performance analog and RF semiconductors, acquired by Diodes Incorporated in 2008.

ZMV829BTC belongs to the 830-series hyperabrupt varactor family, engineered specifically for low-phase-noise frequency control in crystal oscillator and RF filter applications demanding tight CV tolerance and high Q in miniature SMT packages.

FAQ

What is the maximum recommended reverse voltage for continuous operation?

ZMV829BTC has a rated reverse breakdown voltage of 25 V minimum, but continuous operation should be limited to ≤20 V to maintain long-term reliability and avoid accelerated leakage increase. Derating to 15 V is advised for designs requiring >10-year field life under thermal cycling.

Does ZMV829BTC require special PCB layout considerations for RF performance?

Yes-keep anode and cathode traces short (<2 mm), use solid ground plane beneath SOT23, and isolate tuning voltage trace from RF paths using guard rings. Avoid vias near pins; place DC-blocking capacitor within 1 mm of Pin 1 to preserve SRF and minimize parasitic inductance.

Is ZMV829BTC compatible with lead-free reflow profiles?

Yes-ZMV829BTC's SOT23 package is qualified for JEDEC J-STD-020D-compliant lead-free reflow, with peak temperature up to 260°C for 30 seconds. Preheat ramp rate must not exceed 3°C/s to prevent die attach delamination.

How does the capacitance tolerance grade affect oscillator design?

ZMV829BTC Grade A (±5%) reduces initial frequency offset in VCXOs, lowering post-calibration trim time and test cost. Grade B (±7.5%) increases binning spread and may require additional DAC steps or wider PLL lock range in production firmware.