Diodes Incorporated ZMV829ATC

Overview

ZMV829ATC from Zetex Semiconductors is a silicon hyperabrupt varactor diode optimized for voltage-controlled frequency tuning in precision oscillators. It delivers 8.2 pF nominal capacitance at 2 V, 4.3–5.8 capacitance ratio (C₂/C₂₀), ≥250 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 ZMV829ATC datasheet, ZMV829ATC pinout, ZMV829ATC application, or ZMV829ATC equivalent, key selection criteria include its hyperabrupt CV slope, tight ±5% capacitance tolerance (Grade A), SOT23 package compatibility with high-frequency PCB layouts, and guaranteed operation from –55°C to +150°C in thermally demanding RF modules.

Technical Context

The ZMV829ATC employs a hyperabrupt junction profile engineered to produce steep, linearized C–V response-critical for stable frequency pulling in voltage-controlled crystal oscillators. Its 25 V reverse breakdown rating and 300–400 ppm/°C temperature coefficient of capacitance are specified for bias stability across industrial temperature ranges.

This device operates exclusively under reverse-biased conditions, where capacitance varies inversely with applied DC tuning voltage. Its low IR ensures minimal thermal drift and phase noise contribution in closed-loop PLL systems requiring sub-radian jitter performance.

Key Specifications

Pinout & Package

Package: SOT23 - 3-pin surface-mount plastic package (JEDEC TO-236AB), 2.67–3.05 mm length, 1.20–1.40 mm width, 0.95 mm nominal height; optimized for RF layout with low parasitic inductance and thermal resistance (R_θJA = 300°C/W).

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, ZMV829ATC offers the optimal balance of tuning linearity, low-leakage bias stability, and industrial-grade temperature resilience-making it the preferred choice for mission-critical VCXOs where phase noise and long-term drift are design-limiting factors.

Availability

ZMV829ATC is available at Aetrix Electronics and suitable for VCXO design, TCXO compensation, and mobile radio VCO tuning requiring stable component supply, consistent CV grading, and RoHS-compliant SMT assembly.

Supply support for ZMV829ATC 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.

ZMV829ATC belongs to the 830 Series hyperabrupt varactor family, developed specifically for low-phase-noise frequency control in wireless infrastructure, precision timing modules, and portable communications equipment.

FAQ

What is the maximum recommended reverse voltage for continuous operation?

The ZMV829ATC has a minimum reverse breakdown voltage of 25 V, but for reliable long-term operation, Zetex specifies a maximum continuous reverse voltage of 20 V. Exceeding this risks irreversible junction degradation and increased leakage current, especially above 85°C ambient. Derating to 15 V is advised in high-reliability telecom applications.

Can ZMV829ATC be used in series or parallel configurations?

Yes-ZMV829ATC supports both configurations. In series, total capacitance decreases and voltage rating increases (e.g., two in series handle 40 V at half the C). In parallel, capacitance sums while maintaining same voltage rating; however, mismatched units cause unequal voltage sharing, so matched-grade (A or B) devices are required for parallel use.

Is the SOT23 pinout compatible with standard pick-and-place equipment?

Yes-the ZMV829ATC in SOT23 uses JEDEC-standard pin 1 (anode), pin 2 (cathode), and pin 3 (NC), with 0.95 mm nominal height and 0.65 mm pitch. It is fully compatible with Fuji CP7, Siemens SIPLACE, and Universal Instruments platforms using standard SOT23 nozzle and vision alignment settings.

Does ZMV829ATC require special ESD handling during assembly?

Yes-ZMV829ATC is rated Class 1B per JEDEC JS-001 (250–500 V HBM). Standard ESD controls (wrist straps, grounded workstations, ionizers) are mandatory. Avoid direct contact with pins during manual handling, and ensure reflow profiles do not exceed 260°C peak for >10 seconds to prevent junction damage from thermal stress.