BC178 PNP Transistor

• It is a PNP transistor designed to be used in general purpose switching and amplification applications. Looking at the pin layout of the transistor the pin1 is Emitter, pin2 is Base and pin3 is Collector. It is a transistor of BC17x series which also contains other two transistors which are BC177 and BC179. There is also the NPN complementary series of these transistors which contains BC107, BC108, and BC109. All these transistors are widely used in different types of commercial electronic applications. Looking at the absolute maximum ratings of the transistor, max collector-emitter voltage is -25V, the max collector current is -100mA, max emitter-base voltage is -5V, max collector dissipation is 300mW and max storage and operating temperature of the transistor is -65 °C to +175 °C. These are the maximum limits of the transistor so it is suggested to not use the transistor to its absolute maximum ratings and always stay at leat 20% below from these ratings for good performance. As regarding to the electrical characteristics some main characteristics are as follows: it has a DC current gain of 120 to 500, the transition frequency is 200MHz and maximum noise figure is 10dB.
• BC178 can be used in wide variety of general purpose switching and amplification applications. It has a collector current of 100mA which means it can drive load of up to 100mA and suitable to drive loads such as LEDs, low current motors, ICs, power transistors etc. Moreover, it is also a good candidate as a small signal amplifier and due to its good DC current gain and low noise features it can also be used in audio preamplifiers and also to amplify different types of small signals in electronics. Additionally, the transition frequency of 200MHz also makes it ideal to be used in RF circuits.
• PNP Complementary: PNP Complementary of BC178 is BC108
• Replacement and Equivalent: BC560, BC556,  BC558,  BC557,  BC559

Applications:

• Signal Amplification
• Audio Amp Stages
• Audio amplifier circuits
• Output of Microcontrollers for Driving Different Loads
• Drive Loads Under 800mA