Table of Contents
What is cross-coupled pair?
The cross-coupled pair (XCP) is such a topology: it has evolved for 95 years and adapted itself to various device technologies, supply voltages, and operation speeds. In this and future columns, we analyze this circuit’s properties and study its applications in both analog and digital design.
What is cross-coupled inverter?
The inverters are cross-coupled to form a flip-flop for storing data. The flip-flop is connected between a power source VCC and the ground. A single transfer gate MOS transistor Q0 is connected to the flip-flop for reading/writing data.
How does an emitter follower work?
Introduction: Understanding Emitter-Followers: Using Transistors to Reduce Sag. Many electronic circuits, including voltage dividers and filters, produce signals that sag when current is drawn. An Emitter-Follower uses a transistor to reduce this sag by a factor of 100.
What is the meaning of emitter follower?
In electronics, a common collector amplifier (also known as an emitter follower) is one of three basic single-stage bipolar junction transistor (BJT) amplifier topologies, typically used as a voltage buffer.
Why is emitter follower called so?
Because of this behavior, the common-collector amplifier circuit is also known as the voltage-follower or emitter-follower amplifier, because the emitter load voltage follows the input so closely.
Why is emitter follower useful?
The emitter follower is widely used as a buffer amplifier to reduce the loading on the previous stage and provide a lower impedance output for any following circuits. The electronic circuit design for the stage is also very straightforward and easy to accomplish.
What is coupling reaction give example?
Explain coupling reaction giving example. When benzene diazonium chloride reacts with phenol in which the phenol molecules at its para position is coupled with the diazonium salt to form p-hydroxyazobenzene. This reaction is known as coupling reaction.
What was the first cross-coupling reaction?
Carbon–carbon cross-coupling
| Reaction | Year | Reactant B |
|---|---|---|
| Corey–House synthesis | 1967 | sp2, sp3 |
| Kumada coupling | 1972 | sp2 |
| Heck reaction | 1972 | sp2 |
| Sonogashira coupling | 1975 | sp3 sp2 |
Why emitter follower has no voltage gain?
The voltage gain of an emitter follower is just a little less than one since the emitter voltage is constrained at the diode drop of about 0.6 volts below the base . Its function is not voltage gain but current or power gain and impedance matching.
Which coupling is used for low frequency signal?
The advantage of direct coupling is very good low frequency response, often from DC to the highest operating frequency that the system will allow.
Why CE configuration is used for amplifier?
⦁ CE is most widely used because it provides the voltage gain required for most of the day to day applications of preamp and power amps. This is not possible in CB mode.
How many types of coupling reactions are there?
two types
Types of Coupling Reactions Coupling reactions can be classified into two types based on the chemical species that are combined by them: Homo-coupling reactions: Here, two identical chemical species are combined to yield a single product.
Why is the emitter resistor decoupled from the collector?
The emitter resistor has a fixed voltage across it, and it must, therefore, pass a fixed current from the emitter. IE = IC − IB, but since IB is so small, IE ≈ IC, and if we have a fixed emitter current, then collector current is also fixed. The emitter is decoupled to prevent negative feedback from reducing the AC gain of the circuit.
What is the output resistance of a cathode follower in a transistor?
Since hfe for a small-signal transistor is likely to be ≈400, a 100 Ω resistor in the emitter makes the output resistance 1/ hoe ≈40 kΩ. The cathode follower then multiplies this resistance by its μ, perhaps 20, to give RL ≈8 MΩ, which is even better than a μ -follower can achieve.
Why do we use two emitter resistors in a Darlington amplifier?
The two emitter resistors give the freedom needed to choose both a Thévenin equivalent supply voltage and an emitter resistance. which is larger than that of the CE by a factor of (β + 1). A Darlington amplifier makes a good input stage for voltage and transconductance amplifiers because of its high input resistance.
What is the output resistance of a transistor?
When transistor ro is taken into account, output resistance involves two parallel collector resistances with relatively low rc, especially for the driven transistor.