## What is a 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 oscillator?

Abstract: Proves that a system consisting of a cross-coupled pair of certain subsystems that are themselves cross-coupled is capable of generating four signals that are exactly in quadrature and equal in amplitude.

**Why is LC circuit called tank circuit?**

An older name is “tank circuit,” because its operation is analogous to a tank in a fluid system, in which the dimensions of the tank define the natural frequency observed when fluid is pulsed through the tank. Learn More: LC Oscillator Has 1% THD.

**What is the difference between LC and RC oscillators?**

The major difference between the LC and RC oscillator is that the frequency-determining device in the RC oscillator is not a tank circuit. Remember, the LC oscillator can operate with class A or C biasing because of the oscillator action of the resonant tank.

### Why inductor is connected in series and capacitor in parallel?

When inductors are connected together in parallel so that the magnetic field of one links with the other, the effect of mutual inductance either increases or decreases the total inductance depending upon the amount of magnetic coupling that exists between the coils.

### What is the impedance of LC circuit?

The total impedance of a series LC circuit approaches zero as the power supply frequency approaches resonance. The same formula for determining resonant frequency in a simple tank circuit applies to simple series circuits as well.

**What are RC and RL circuits used for?**

RC and RL circuits are used to provide filtering, waveshaping, and timing. The capacitor is most commonly used. Capacitors are smaller and more economical than inductors and do not of strong magnetic fields. An RC series circuit contains a voltage source with a resistor and a capacitor in series.

**Which oscillator is more stable LC or RC?**

Crystal oscillator

A Crystal oscillator has much better frequency stability than LC or RC oscillators. It has a very high Q-factor. A crystal oscillator is basically a tuned – circuit oscillator using a piezoelectric crystal as a resonant tank circuit.

#### Why capacitor is connected in parallel?

A capacitor is a device used to store charges. By connecting the capacitor in parallel the resulting circuit will be able to store more energy since the equivalent capacitance increases.

#### How do you know if a capacitor is in series or parallel?

If each capacitor has BOTH terminals connected to BOTH terminals of the others, then they are in parallel. If each capacitor has only one terminal connected to one terminal of another capacitor, they are in series.

**Why a parallel LC circuit is inductive?**

The parallel LC circuit connected in parallel with the load will act as a band-pass filter. At frequency below resonant frequency i.e. f> XC. Hence the circuit is inductive.