BB159 Technical Summary

BB159 Variable Capacitance Diode Technical Summary

Overview

The BB159 is a high-performance variable capacitance diode (varactor) designed for applications requiring precise voltage-controlled capacitance tuning. This surface-mount device offers excellent linearity and low series resistance in an extremely compact plastic SMD package, making it ideal for space-constrained RF designs.

Engineered for superior tuning performance, the BB159 provides a capacitance ratio of 9 with a nominal capacitance of 2.1pF at 28V, enabling wide tuning ranges in oscillator and filter circuits. Its robust construction ensures reliable operation across various environmental conditions.

Key Features

Exceptional Linearity: Provides smooth, predictable capacitance variation with applied voltage
Compact SMD Package: Ultra-small plastic surface-mount form factor saves board space
Optimized Capacitance Ratio: C28 = 2.1pF with a ratio of 9 delivers wide tuning range
Low Series Resistance: Minimizes losses for improved Q factor in resonant circuits
RoHS Compliant: Meets environmental standards for lead-free manufacturing
Wide Operating Voltage Range: Suitable for various biasing requirements

Applications

The BB159 is particularly suited for high-frequency applications where precise electronic tuning is required:

Voltage-Controlled Oscillators (VCOs): Provides stable frequency tuning in phase-locked loops and RF synthesizers
RF Filters: Enables adjustable bandpass and notch filtering in communication systems
Tuning Circuits: Used in radio receivers and television tuners for channel selection
Frequency Multipliers: Supports harmonic generation in RF systems
Automatic Frequency Control: Facilitates feedback-based frequency stabilization
Mobile Communication Devices: Ideal for smartphones, tablets, and IoT devices requiring compact tuning solutions

Electrical Characteristics

(All measurements at T_amb = 25°C unless otherwise specified)

Absolute Maximum Ratings

Reverse Voltage (V_R): 30V
Power Dissipation (P_tot): 150mW
Storage Temperature Range: -55°C to +150°C
Operating Temperature Range: -40°C to +85°C

Typical Characteristics

Capacitance at 28V (C₂₈): 2.1pF (typical)
Capacitance Ratio (C₁/C₂₈): 9 (minimum)
Series Resistance (R_S): 0.8Ω (maximum at 1MHz)
Quality Factor (Q): 200 (minimum at 1MHz, V_R = 28V)
Breakdown Voltage (V_BR): 30V (minimum)
Leakage Current (I_R): 10nA (maximum at V_R = 28V)

Capacitance vs. Voltage Curve

The BB159 exhibits a smooth, monotonic capacitance-voltage characteristic following the relationship:

C(V) = C₀ / (1 + V/φ)^γ

Where φ is the built-in potential and γ is the grading coefficient (typically 0.5 for abrupt junctions).

Package Information

SOD-323 (SC-76) Package Dimensions

Package Type: Plastic surface-mount SOD-323 (SC-76)
Dimensions: 1.7mm × 1.25mm × 0.95mm (L×W×H)
Terminal Pitch: 0.95mm
Terminal Material: Matte tin-plated copper leads
Moisture Sensitivity Level (MSL): MSL1 (unlimited floor life at ≤30°C/85%RH)