A switched-capacitor circuit is a circuit that utilizes the switching properties of a transistor to switch between two or more capacitors in a circuit. This all...
A switched-capacitor circuit is a circuit that utilizes the switching properties of a transistor to switch between two or more capacitors in a circuit. This allows the circuit to operate in different modes, offering various functionalities such as filtering, amplification, and signal processing.
The basic principle behind switched-capacitor circuits lies in the ability of transistors to control the flow of current between the two capacitors. By varying the voltage applied to the gate terminal of the transistor, the circuit can be switched between two different states:
Capacitor 1 mode: When a positive voltage is applied to the gate terminal, the transistor turns on and conducts current from the positive supply to the output node. Capacitor 1 is charged.
Capacitor 2 mode: When a negative voltage is applied to the gate terminal, the transistor turns off and blocks current flow from the positive supply to the output node. Capacitor 2 is discharged.
The switching between these two modes allows the circuit to behave like a capacitor with either one of the two capacitors. This switching behavior can be manipulated by varying the voltage and the resistance values of the capacitors and the transistor.
Switched-capacitor circuits find numerous applications in electronic devices, including:
Filter circuits: They can be used to filter out unwanted signals and maintain a desired signal quality.
Amplifier circuits: They can be used to amplify a weak signal by charging a capacitor and then discharging it through the output transistor.
Oscillator circuits: They can be used to generate a controlled waveform by charging and discharging a capacitor at a specific frequency.
Overall, switched-capacitor circuits offer a versatile approach to circuit design that allows for various functionalities and signal processing applications