Why do we want infinite input impedance?

Why do we want infinite input impedance?

Infinite input impedance would allow one to feed any amount of voltage into a load without it absorbing any power. Zero input impedance would allow one to feed any amount of current into a load without it absorbing any power.

Why is op amp gain infinite?

In an ideal op amp, the open loop gain is infinite, which means that any voltage differential on the two input terminals will result in an infinite voltage on the output. In an ideal op amp, the impedance of the two input terminals is infinite, which means that no current enters the op amp from the inputs.

Does an ideal op amp have infinite input impedance?

The ideal op amp is an extension of the concept of an ideal amplifier. An ideal amplifier has infinite input impedance, zero output impedance, and a fixed gain at all frequencies. An ideal op amp has infinite input impedance and zero output impedance, but has infinite gain.

What is the input impedance of an op amp?

The input impedance of an op amp is the impedance that is seen by the driving device. The lower the input impedance of the op amp, the greater is the amount of current that must be supplied by the signal source.

Why is the low output impedance and high input impedance of an op amp?

Op amps have high input impedance and low output impedance because of the concept of a voltage divider, which is how voltage is divided in a circuit depending on the amount of impedance present in given parts of a circuit. Op amps are voltage gain devices.

What does infinite impedance mean?

At that special frequency, the inductor current with its 90° phase lag and the capacitor current with its 90° phase lead combine to cancel each other out. We have no current when a voltage of this frequency is applied. That’s infinite impedance.

What is infinite input impedance?

Infinite – Input impedance is the ratio of input voltage to input current and is assumed to be infinite to prevent any current flowing from the source supply into the amplifiers input circuitry ( IIN = 0 ).

Why does no current flow in an op amp?

Infinite input impedance means that no current flows into the input terminals of an ideal op amp. The ideal op amp also has zero output impedance, and most certainly provides current. An OpAmp can be considered a voltage-controlled voltage source. So it is an impedance converter.

Why is the low output impedance and high input impedance of an op-amp?

Why is the input impedance of an op-amp very high?

Op amps need high input impedance because they are voltage-gain devices. In order for voltage to drop across the input, the impedance has to be very high, as ohm’s law states, V=IR. It’s also important to prevent the loading effect. If the impedance were small, the current draw would be high.

Why input impedance should be high and output impedance should be low?

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.