ZC834ATA

Overview

The ZC834ATA is a silicon hyperabrupt varactor diode from the 830 series, designed for frequency control and filtering applications. It features closely controlled capacitance-voltage characteristics and high Q factors to ensure excellent phase noise performance. The device operates with a reverse voltage leakage of typically 20 nA at 20V and supports an operating temperature range from -55°C to +150°C. Electrical specifications include a nominal capacitance of 47 pF at 2V reverse bias (measured at 1MHz), a minimum Q factor of 200 at 3V and 50MHz, and a capacitance ratio (C2/C20) between 5.0 and 6.5.

Feature Summary

• Hyperabrupt junction design providing high tuning ratios for efficient frequency modulation
• Low reverse current leakage ensures minimal impact on oscillator phase noise
• Tight capacitance tolerance guarantees consistent circuit performance across production batches

Applications

• Voltage Controlled Crystal Oscillators (VCXO)
• Temperature Compensated Crystal Oscillators (TCXO)
• Wireless communication systems
• Mobile radio equipment

Procurement Notes

Verify component authenticity by checking manufacturer markings against official order code tables. Confirm package type matches the required surface mount format. Ensure handling procedures account for electrostatic discharge sensitivity. Review datasheet revisions for any updates to absolute maximum ratings or thermal characteristics before finalizing procurement specifications.

Selection Notes

Select the ZC834ATA when a nominal capacitance near 47pF is required at low reverse bias voltages. Compare the C2/C20 ratio against other series members if specific tuning linearity is critical. Consider the SOT23 or SOD523 package availability based on board space constraints. Evaluate the 200nA leakage specification against strict phase noise requirements in sensitive RF front-ends.

Part Context

This component belongs to the 830 series of silicon hyperabrupt varactor diodes originally manufactured by Zetex Semiconductors. The series includes variants like ZC829 through ZC836, differentiated primarily by their nominal capacitance values ranging from approximately 8pF to 100pF. These devices are engineered for high-frequency stability in precision timing circuits.

Replacement Considerations

Direct substitutes within the same family include ZC834BTA, which shares identical electrical characteristics but may differ in binning tolerances. Other series members such as ZC833ATA or ZC835ATA offer different capacitance values and should only be considered if circuit tuning ranges can accommodate the shift.