Features / Technical Specifications:

• Package Type: TO-92
• Transistor Type: PNP
• Max Collector Current(I_C): -100mA
• Max Collector-Emitter Voltage (V_CE): -45V
• Max Collector-Base Voltage (V_CB): -50V
• Max Emitter-Base Voltage (VBE): -5V
• Max Collector Dissipation (Pc): 500 Milliwatt
• Max Transition Frequency (fT): 100 MHz
• Minimum & Maximum DC Current Gain (h_FE): 125 to 800
• Max Storage & Operating temperature Should be: -65 to +150Centigrade

NPN Complementary:

NPN Complementary of BC557 is BC547

Replacement and Equivalent:

Alternative transistors for BC557 are 2N3906, 2N4403, BC556, BC327 output pins of some equivalents are different please see pinout details of the equivalent transistor before replacing in the circuit.

BC557 Transistor Explained / Description:

BC557 is a widely used PNP bipolar junction transistor manufactured in small TO-92 package. It is a general purpose PNP transistor that can be used as a switch or amplifier in electronic circuits. Its HFE ratings are 125 to 800 which makes it an ideal transistor to use as a small signal amplifier in electronic circuits for example for audio signal amplification or other, the HFE ratings of BC557 can be determined by the last letter after its number for example BC557A HFE ratings are 110-220, BC557B HFE ratings are 200-450 and BC557C HFE ratings are 420-800. The max collector dissipation is 500 milliwatt which is also an another good point to use it in amplification stages. Moreover it will also perform well when used it as a switch for load under 100mA. The transistor has also good collector to emitter (VCE) value that is -45V, therefore you can easily use it in circuits using 40 to 45 volts DC.

Beside these uses BC557 is also a good general purpose PNP transistor to use in your hobby electronics projects therefore it is a must to have transistor in your electronics LAB.

Where We Can Use it & How to Use:

As mentioned above BC557 is a general purpose transistor therefore it can be used wide variety of general purpose applications for example it can be used as an audio amplifier in small radios, electronic buzzers, electronic bells and other sound circuits that require small amplification. Due to the good gain of this transistor can also be used in audio preamplifier stages. Beside these uses this transistor can also perform as a switch in electronic applications for 100mA load, it can be used to switch any part of an electronic circuit, other high-power transistors, LEDs, relays etc.

Applications:

Preamplifier

Small signal audio amplifier

Driving Loads under 0.1mA or 100mA

Any general purpose application that comes under its ratings.

How to Safely Long Run in a Circuit:

To safely run this transistor for good performance for a long time in your electronic circuit it is essential to not operate transistor under -45V DC, always use suitable base resistor, do not provide this transistor more than -100mA load, the operating and storage temperature around the transistor should be under -65 to +150 Centigrade, and always check the pinout of the transistor before placing it in an electronic circuit if wrongly placed then check the transistor again before placing it in the circuit.