How does the Colpitts oscillator work?
Oscillator is an amplifier with the positive feedback and it converts DC input signal into AC output waveform with certain variable frequency drive and certain shape of output waveform (like sine wave or square wave, etc) by using the positive feedback instead of input signal.
What is the condition for oscillation in Colpitts oscillator?
Explanation: the condition for sustained oscillation in a colpitts oscillator is c2/c1 = gm/gi. here c1 and c2 are the capacitance in the feedback network, gm is the transconductance of the transistor and gi is the input admittance.
What is the formula for Colpitts oscillator?
In this circuit, we calculate a colpitts oscillator frequency based on the formula, frequency= 1/2π√ LCt , where L is the value of the inductor and CT is the equivalent capacitance of the capacitors in series.
What is the output of Colpitts oscillator?
The frequency of the oscillator can be from around 500 KHz to 2 MHz depending on the values chosen for C1, C2 and L1. Start with L1 = 100 uH and C1 = 4.7 nF and C2 = 1 nF. This oscillator circuit can produce a sine wave output in excess of 10 Vpp at an approximate frequency set by the value chosen for L1.
What is the basic principle of oscillator?
There are many types of electronic oscillators, but they all operate according to the same basic principle: an oscillator always employs a sensitive amplifier whose output is fed back to the input in phase. Thus, the signal regenerates and sustains itself. This is known as positive feedback.
What type of feedback is used in Colpitts oscillator?
Voltage series feedback
Voltage series feedback is used in Colpitts oscillator. In voltage series feedback a part of output voltage is fed back to input.
Which type of feedback is used in Colpitts oscillator?
How is positive feedback supplied in a Colpitts oscillator?
In a Colpitts oscillator (shown below), positive feedback is supplied through a capacitive divider.
What is the frequency range of Colpitts oscillator?
20 kHz to 300 MHz
Colpitts oscillators range from 20 kHz to 300 MHz. They can even be used for microwave applications as their capacitors provide a low reactance path for high-frequency signals.
How does an oscillator work in a circuit?
An oscillator is a circuit which produces a continuous, repeated, alternating waveform without any input. Oscillators basically convert unidirectional current flow from a DC source into an alternating waveform which is of the desired frequency, as decided by its circuit components.
What is an oscillator circuit?
Advertisements. An Oscillator circuit is a complete set of all the parts of circuit which helps to produce the oscillations. These oscillations should sustain and should be Undamped as just discussed before.
How many capacitors are present in Colpitts oscillator?
Clarification: Capacitive voltage divider network is used for giving positive feedback in Colpitts oscillator. Oscillations across the capacitor are applied at the base-emitter junction and appear across the collector as an amplified output. The amount of feedback depends on the ratio of the two capacitors being used.