BC808 PNP Transistor Technical Summary

Overview

The BC808 is a PNP bipolar junction transistor (BJT) housed in a compact SOT323 plastic package. Designed for general-purpose amplification and switching applications, this transistor offers a balance of high current capability and low voltage operation. Its small form factor makes it suitable for space-constrained designs, while its electrical characteristics ensure reliable performance in a variety of electronic circuits.

Features

• High Current Capability: Supports a maximum collector current (Ic) of 500 mA, making it suitable for driving moderate loads.
• Low Voltage Operation: Maximum collector-emitter voltage (V_CEO) of 45 V, enabling use in low-voltage circuits.
• Compact Package: SOT323 package provides a small footprint, ideal for high-density PCB layouts.
• General-Purpose Use: Suitable for amplification, switching, and signal processing applications.
• Plastic Encapsulation: Ensures durability and protection against environmental factors.

Applications

The BC808 PNP transistor is versatile and can be employed in a wide range of electronic applications, including but not limited to:

• Signal Amplification: Used in audio amplifiers, sensor interfaces, and other low-power signal conditioning circuits.
• Switching Circuits: Acts as a switch in relay drivers, LED drivers, and other load-control applications.
• Voltage Regulation: Incorporated in linear regulators and power management circuits.
• Oscillators and Timers: Part of feedback networks in oscillator designs and timing circuits.
• Consumer Electronics: Found in portable devices, remote controls, and other battery-operated systems.

Electrical Characteristics

The following table summarizes the key electrical parameters of the BC808 transistor under standard test conditions (unless otherwise specified):

Absolute Maximum Ratings

• Collector-Emitter Voltage (V_CEO): 45 V
• Collector-Base Voltage (V_CBO): 50 V
• Emitter-Base Voltage (V_EBO): 5 V
• Collector Current (I_C): 500 mA (continuous)
• Total Power Dissipation (P_tot): 250 mW (at 25°C)
• Operating Junction Temperature (T_j): -55°C to +150°C
• Storage Temperature (T_stg): -55°C to +150°C

Typical Electrical Characteristics (T_a = 25°C)

• DC Current Gain (h_FE): 100 - 600 (at I_C = 2 mA, V_CE = 5 V)
• Collector-Emitter Saturation Voltage (V_CE(sat)): 0.25 V (max) (at I_C = 100 mA, I_B = 10 mA)
• Base-Emitter Saturation Voltage (V_BE(sat)): 0.9 V (max) (at I_C = 100 mA, I_B = 10 mA)
• Transition Frequency (f_T): 100 MHz (min) (at I_C = 10 mA, V_CE = 5 V)
• Output Capacitance (C_obo): 4 pF (max) (at V_CB = 10 V, f = 1 MHz)

Package Information

The BC808 is available in a SOT323 (SC-70) surface-mount package, which is designed for automated assembly processes. The package dimensions and pin configuration are as follows:

SOT323 Package Dimensions

• Package Type: SOT323 (SC-70)
• Mounting Style: Surface Mount
• Number of Pins: 3
• Package Height: 1.1 mm (max)
• Package Width: 2.0 mm (max)
• Package Length: 2.1 mm (max)
• Lead Pitch: 1.25 mm

Pin Configuration

• Pin 1 (Emitter): Connected to the emitter terminal of the transistor.
• Pin 2 (Base): Connected to the base terminal for biasing control.
• Pin 3 (Collector): Connected to the collector terminal, which handles the primary current flow.

Thermal Characteristics

Proper thermal management is critical to ensure the reliability and longevity of the BC808 transistor in operation. The following thermal parameters should be considered:

• Thermal Resistance, Junction-to-Ambient (R_θJA): 357°C/W (typical for SOT323 package on a standard FR4 PCB)
• Thermal Resistance, Junction-to-Lead (R_θJL): 125°C/W

To maximize performance, it is recommended to use adequate PCB copper area or heatsinking for high-current applications.

Reliability and Quality

The BC808 transistor is manufactured using high-quality materials and processes to ensure consistent performance and reliability. It complies with industry standards for moisture sensitivity (MSL Level 1) and is RoHS compliant, making it suitable for use in environmentally conscious designs.

Conclusion

The BC808 PNP transistor is a versatile and reliable component suitable for a wide range of low-voltage, moderate-current applications. Its compact SOT323 package, combined with robust electrical characteristics, makes it an excellent choice for designers seeking a balance of performance and space efficiency. Whether used in amplification, switching, or signal processing, the BC808 delivers consistent results in demanding electronic circuits.