BB181,335

Overview

The BB181 is a VHF variable capacitance diode fabricated in planar technology and encapsulated in the SOD523 (SC-79) ultra-small plastic surface-mounted device package. It features excellent linearity and a high capacitance ratio of 14 between 0.5V and 28V reverse bias. The diode exhibits low series resistance of 3 Ω at 470 MHz with 9 pF capacitance. Reverse current is limited to 10 nA at 30V and 25°C, rising to 200 nA at 85°C. Capacitance ranges from 17 pF at 0.5V to 1.055 pF at 28V. The marking code is 'N', indicating the cathode via a bar.

Feature Summary

• Excellent linearity for signal integrity
• Ultra-small plastic SMD package for space-constrained designs
• High capacitance tuning ratio across voltage range

Applications

• Electronic tuning in satellite tuners
• Tunable coupling circuits
• Voltage Controlled Oscillators (VCO)

Procurement Notes

Verify the specific ordering suffix when sourcing components. The base part number is BB181, while the variant BB181,335 corresponds to the standard reel packaging configuration. Confirm the presence of the 'N' marking code on received units to ensure authenticity and correct orientation identification during assembly processes.

Selection Notes

Select this component for VHF applications requiring precise electronic tuning with minimal footprint. Evaluate the capacitance-voltage characteristics against circuit requirements, noting the ratio spans from approximately 12 to 16 depending on temperature conditions. Ensure operating voltages remain within the 30V reverse limit to maintain reliability and prevent junction damage.

Part Context

This component belongs to NXP's portfolio of passive semiconductor devices designed for RF and microwave applications. As a varactor diode, it serves as a critical element in frequency synthesis and filtering systems where voltage-dependent capacitance is required for dynamic adjustment without mechanical moving parts.

Replacement Considerations

No direct substitute part numbers are documented in the provided datasheet. Designers must evaluate alternative varactors based on matching capacitance ratios, package dimensions, and maximum reverse voltage ratings to ensure functional compatibility in existing layouts.

FAQ

How is the cathode identified on the BB181 package?

The marking bar printed on the top surface of the SOD523 package indicates the cathode terminal.

What is the typical capacitance ratio of the BB181?

The capacitance ratio Cd(0V5)/Cd(28V) typically ranges from 12 to 16 at 1 MHz.

What is the maximum reverse voltage rating?

The absolute maximum reverse voltage (VR) rating is 30 V.