# Why Darlington pair is used?

## Why Darlington pair is used?

The Darlington Pair offers a number of advantages. It is primarily used because it offers a particularly high current gain and this also reflects into a high input impedance for the overall Darlington circuit when compared to a single transistor.

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What is the difference between a Sziklai pair and a Darlington pair?

The Sziklai Pair uses transistors of complementary polarity to achieve the same gain as the Darlington Pair, but with improved VBE characteristics. Only Q1’s base-emitter junction is exposed to the outside world. However, the Sziklai pair does not suffer as badly as the Darlington in terms of VBE.

### What two components make the Darlington pair?

A Darlington Transistor configuration, also known as a “Darlington pair” or “super-alpha circuit”, consist of two NPN or PNP transistors connected together so that the emitter current of the first transistor TR1 becomes the base current of the second transistor TR2.

How do you find AV in a circuit?

The voltage gain of a common emitter circuit is given as Av = ROUT/REMITTER where ROUT represents the output impedance as seen in the Collector leg and REMITTER is equal the the equivalent resistance in the Emitter leg either with or without the bypass capacitor connected.

#### How a Darlington pair works?

A Darlington Pair acts as one transistor but with a current gain that equals: Total current gain (hFE total) = current gain of transistor 1 (hFE t1) x current gain of transistor 2 (hFE t2) So for example if you had two transistors with a current gain (hFE) = 100: (hFE total) = 100 x 100 (hFE total) = 10,000 You can see …

How does Darlington pair work?

## Which is a Darlington pair?

In electronics, a multi-transistor configuration called the Darlington configuration (commonly called a Darlington pair) is a circuit consisting of two bipolar transistors with the emitter of one transistor connected to the base of the other, such that the current amplified by the first transistor is amplified further …

Why should input impedance be high?

The reason for making high input impedance is that “The circuit can be driven by any source” to avoid any loading effect. This ensures maximum current is provided by source. The reason to ensure low output impedance is that “The circuit can drive any load”, even the load impedance is small in magnitude.

### Why Darlington pair has high input impedance?

The main advantage of a Darlington transistor is the high current gain. So, a small amount of base current can trigger the transistor. It offers high input impedance which translates into an equal decrease in output impedance. It is a single package.

What is Darlington pair?

It mentions benefits or advantages of Darlington transistor and drawbacks or disadvantages of Darlington transistor. What is Darlington Pair? US Engineer Sidney Darlington has invented this transistor configuration in 1953.

#### What is Darlington pair transistor?

It mentions benefits or advantages of Darlington transistor and drawbacks or disadvantages of Darlington transistor. What is Darlington Pair? US Engineer Sidney Darlington has invented this transistor configuration in 1953. It uses two standard BJT transistors connected together to form pair as shown.

How to calculate the current gain of a Darlington pair?

Darlington Transistor Pair Current Gain Calculation: In the below image we can see two PNP or two NPN transistors are connected together. The overall current gain of the Darlington pair will be- Current gain (hFE) = First transistor gain (hFE1) * Second transistor gain (hFE2)

## What is the difference between NPN Darlington and PNP Darlington?

We can see NPN Darlington consist two NPN transistors, and PNP Darlington consist two PNP transistors. The first transistor’s emitter is directly connected across the base of other transistor, also the collector of the two transistors are connected together. This configuration is used for both NPN and PNP Darlington transistors.