BB155 Variable Capacitance Diode

Overview

The BB155 is a high-performance variable capacitance diode (varactor) designed for applications requiring precise and stable voltage-controlled capacitance tuning. Manufactured with advanced semiconductor technology, the BB155 offers excellent linearity, low series resistance, and minimal capacitance spread, making it ideal for RF and microwave applications. Its compact SMD package ensures easy integration into modern circuit designs while maintaining superior electrical performance.

Features

• Very Low Capacitance Spread: Ensures consistent performance across production batches, reducing the need for circuit recalibration.
• Excellent Linearity: Provides a predictable and smooth capacitance change with applied voltage, critical for tuning and filtering applications.
• Low Series Resistance: Minimizes losses, enhancing the Q-factor and overall efficiency in resonant circuits.
• Compact SMD Package: The small plastic surface-mount design saves board space and is compatible with automated assembly processes.
• Wide Operating Voltage Range: Supports flexible biasing conditions for diverse circuit requirements.
• High Reliability: Robust construction ensures stable operation under varying environmental conditions.

Applications

The BB155 is widely used in applications where precise voltage-controlled capacitance is essential. Key application areas include:

• Voltage-Controlled Oscillators (VCOs): Provides stable and linear frequency tuning in communication systems.
• RF Filters: Enables adjustable filtering for signal conditioning in receivers and transmitters.
• Phase-Locked Loops (PLLs): Facilitates accurate frequency synthesis in clock generation and data recovery circuits.
• Tuning Circuits: Used in radio and television tuners for channel selection and signal optimization.
• Frequency Modulators: Supports modulation in wireless communication systems.
• Antenna Matching Networks: Helps in impedance matching for improved signal transmission and reception.

Electrical Characteristics

The following table summarizes the key electrical specifications of the BB155 variable capacitance diode under typical operating conditions (unless otherwise noted):

Absolute Maximum Ratings

• Reverse Voltage (V_R): 30 V
• Forward Current (I_F): 100 mA
• Power Dissipation (P_tot): 250 mW
• Operating Temperature Range (T_op): -55°C to +125°C
• Storage Temperature Range (T_stg): -55°C to +150°C

Typical Electrical Parameters

• Capacitance Range (C_j): 2.5 pF to 20 pF (at V_R = 1 V to 30 V)
• Capacitance Ratio (C_1V/C_30V): 8:1 (typical)
• Series Resistance (R_S): 0.8 Ω (max at V_R = 1 V)
• Quality Factor (Q): 300 (min at 1 MHz, V_R = 1 V)
• Breakdown Voltage (V_BR): 30 V (min)

Package Information

The BB155 is housed in a compact, surface-mount plastic package, designed for high-density PCB layouts and automated assembly processes. The package details are as follows:

Package Dimensions

• Package Type: SOD-323 (Small Outline Diode)
• Dimensions: 1.7 mm x 1.25 mm x 0.95 mm (L x W x H)
• Lead Pitch: 0.65 mm
• Termination: Solderable surface-mount pads

Marking and Identification

The BB155 diode is marked with a unique identifier on the package for traceability and part verification. The marking typically includes:

• Manufacturer's logo or code
• Part number (BB155)
• Date code or batch number

Handling and Storage Recommendations

• Store in a dry environment at temperatures within the specified storage range.
• Use anti-static precautions during handling to prevent damage from electrostatic discharge (ESD).
• Avoid mechanical stress on the package leads during assembly.

Conclusion

The BB155 variable capacitance diode is a versatile and reliable component for applications requiring precise voltage-controlled capacitance tuning. Its excellent linearity, low series resistance, and compact SMD package make it a preferred choice for RF and microwave circuits. Whether used in VCOs, PLLs, or tuning networks, the BB155 delivers consistent performance and high reliability, meeting the demands of modern electronic systems.