Darlington pair

150

03:17:08

Clever method to increase the current gain

published 8 years ago

tjt263

8 years ago

Can you explain it? It doesn't appear to be doing anything.

crake

8 years ago

Beta of the second bjt (on the right) is a product of the first beta and the second beta. Analyze the circuit by hand. You will find ic2=ib1*(beta1*beta2).

ddeepakk13

8 years ago

You can consider the paired transistor setup to be a single transistor with effective beta being equal to the product of their individual beta values. Very useful for getting exponentially higher current gains.

crake

8 years ago

...A single transistor with a required Vbe that is a little higher than a real single transistor.

selman

8 years ago

And the Vbe forward drop voltage is the sum of the individual Vbe voltage of the two transistors.

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.