Configuration of two transistors in which collectors are connected and emitter of first drives base of second, it achieves beta multiplication is called

Configuration of two transistors in which collectors are connected and emitter of first drives base of second, it achieves beta multiplication is called Darlington pair.

.Darlington Pair: CC – CC

• Darlington pair is a special arrangement of two standard NPN or PNP bipolar junction transistors (BJT) connected together
• The Emitter of one transistor is connected to the base of the other to produce a more sensitive transistor with a much larger current gain
• It is useful in applications where current amplification or switching is required; The voltage gain is unity in this case

The symbolic diagram of the Darlington pair is shown below

It has a high current gain β (equal to the product of current gain of individual transistors)

It also has high input impedance and low output impedance.