bc557 pinout

BC557 Transistor datasheet pinout

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BC557 Transistor

BC557 Is the very famous small power general purpose PNP bipolar junction (BJT) transistor. Max output current across the emitter to collector is 100ma. Bc557 is widely available and uses in electronics circuits for the switching, amplifying and For making a Darlington pair. This is available in very small package like To-92. It has low noise and high current gain. It is mainly applicable where low power Audio frequency signal amplification or small load switching required.

Small audio amplifier like headphone amplifier, signal processing and also be used for voltage regulator circuit.

Main characteristics and features of BC557, BC558 transistor

Transistor Type : PNP Bipolar Junction Transistor (BJT)

  • Maximum Collector-Base Voltage (-Vcbo) : 50V
  • Maximum Collector-Emitter Voltage (-Vceo):  45V
  • Continuous Collector Current (-Ic) : Typically around 100mA
  • DC Current Gain (hfe)  : Typically ranges from 110 to 800
  • Maximum Emitter-Base Voltage (-Vebo) :  5V
  • Power Dissipation (Pd)  : Typically around 625mW
  • Operating Frequency : Suitable for low to moderate frequency applications
  • Operating Temperature  : Typically rated for a range between -55°C to 150°C.

PNP Silicon Epitaxial Planar Transistors for switching and AF amplifier applications. These transistors are subdivided into three groups A, B and C according to their current gain. The type BC556 is available in groups A and B, however, the types BC557 and BC558 can be supplied in all three groups. The BC559 is a low-noise type available in all three groups. As complementary types, the NPN transistors BC546 … BC549 are recommended.

Uses of BC557 transistor

  1. Switching:
    • Used as an electronic switch to control the flow of current in a circuit. It can turn on and off electronic devices or other components.
  2. Amplification:
    • Used in amplifier circuits to increase the strength of weak signals. Commonly used in audio amplifiers, signal processing circuits, and other low-power amplification needs.
  3. Oscillator Circuits:
    • Used in oscillator circuits to generate periodic signals, such as in clock generators and tone generators.
  4. Regulator Circuits:
    • Employed in voltage regulator circuits to maintain a constant output voltage despite variations in input voltage or load conditions.
  5. Darlington Pair:
    • Can be used in combination with another transistor to form a Darlington pair, which provides high current gain.Darlington pair transistor
  6. LED Drivers:
    • Used to drive LEDs in various applications, ensuring the proper current is supplied to the LEDs.
  7. Analog Circuits:
    • Used in analog signal processing circuits, such as in sensors and transducers, to process and condition signals.
  8. Relay Drivers:
    • Used to drive relays, allowing low-power control signals to switch high-power loads.
  9. Pulse Width Modulation (PWM) Controllers:
    • Used in PWM controllers for controlling motor speed, light dimming, and other applications requiring variable control.

The BC557 transistor is valued for its low cost, availability, and ease of use, making it a staple component in both hobbyist and professional electronic projects.

Package Type: Available in TO-92, SOT-23, and other surface-mount packages.

BC557 Transistor Equivalent 2N3406(Pin EBC), BD140(ECB), BC157, BC558(CBE), BC559(CBE)

In case of equivalent transistor placement Must check the Pinout configuration of each.

bc557 pinout

Collector – Emitter Voltage (-VCEO)

BC556 : 65V

BC557: 45V

BC558 : 30V

Collector – Base Voltage (-VCBO)

BC556 : 80

BC557 : 50

BC558 : 30

Emitter – Base Voltage (-VEBO) = 5.0 Vdc

Collector Current − Continuous (-IC) = 100ma

Collector Current – Peak (-ICM) = 200ma

TO-92 package

Download datasheet of BC557 pdf



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