Adjustable capacitance circuit and delay adjusting circuit

Abstract

The invention discloses an adjustable capacitor circuit and a delay adjusting circuit. The adjustable capacitance circuit comprises at least one capacitance adjusting unit. The capacitance adjusting unit comprises two adjusting subunits, each adjusting subunit comprises a capacitor, a power one-way conduction tube and a loop module, the first pole of the capacitor serves as the first end of the adjusting subunit, and the second pole of the capacitor is connected with the first pole of the power one-way conduction tube and the second end of the loop module; a second pole of the electric power one-way conduction tube is connected with a control signal end and serves as a second end of the adjusting subunit, a first end of the loop module is connected with a first voltage end, and the two adjusting subunits are arranged in a mirror image mode through the control signal end; the loop module is used for providing a loop for the one-way conduction pipe. The parasitic capacitance of the one-way conduction tube is very small, so that the variable capacitance ratio of the adjustable capacitance circuit can be increased, and the adjustable capacitance circuit can be used in a high-speed circuit. And meanwhile, the application range of the adjustable capacitor circuit can be expanded.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of electronic circuits, in particular to an adjustable capacitance circuit and a delay adjustment circuit. Background technique [0002] As a basic circuit structure, the adjustable capacitance circuit can be widely used in circuits that need to change the node time constant or delay time. For example, in the delay circuit, by setting an adjustable capacitance circuit for adjusting the equivalent capacitance value of the delay circuit, the delay time of the delay circuit can be changed. [0003] In the prior art, the adjustable capacitance circuit may include an adjustable capacitance device for adjusting the capacitance value, for example, the adjustable capacitance device may be a voltage-controlled adjustable capacitance. The adjustment range of the capacitance value of the adjustable capacitor device is relatively small, which is not conducive to realizing a wide range of capac...

AI Technical Summary

Problems solved by technology

Due to the large parasitic capacitance of the MOS tube, the variable capacitance ratio of the adjustable capacitor circuit is relatively small, which limits the scope of use of the adjustable capacitor circuit.

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