Active inductor/capacitor switching circuit

Abstract

The invention discloses an active inductor / capacitor switching circuit. The circuit comprises a first NMOS transistor, a second NMOS transistor, a third NMOS transistor and a fourth NMOS transistor, wherein the source electrode of the first NMOS transistor is connected with a third current source, the drain electrode of the first NMOS transistor is connected with a voltage source, the drain electrode of the second NMOS transistor is connected with a second current source and the grid electrode of the first NMOS transistor, the drain electrode of the third NMOS transistor is connected with the source electrode of the second NMOS transistor, the grid electrode of the third NMOS transistor is connected with the resource electrode of the first NMOS transistor, the resource electrode of the third NMOS transistor is grounded, the drain electrode of the fourth NMOS transistor is connected with the grid electrode of the second NMOS transistor and a first current source, the grid electrode of the fourth NMOS transistor is connected with the resource electrode of the third NMOS transistor, and the drain electrode of the fourth NMOS transistor is grounded. The active inductor / capacitor switching circuit is equivalent to an active inductor when the working frequency of the circuit is low frequency, and is equivalent to an active capacitor when the working frequency of the circuit is high frequency.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to an active inductance / capacitance switching circuit. Background technique [0002] Both inductors and capacitors are important devices in integrated circuit design. Generally speaking, inductors and capacitors appear in the form of passive devices. Inductors are important passive components in the front-end of RF transceivers. RF front-end transceiver modules that require integrated inductors mainly include: low-noise amplifiers, power amplifiers, oscillators, up-conversion mixers, etc. Inductors play an important role in these modules. Taking the low-noise amplifier as an example, the low-noise amplifier is one of the important modules in the radio frequency transceiver. It is mainly used in the communication system to amplify the signal received from the antenna, which is convenient for the subsequent receiver circuit processing. It is precisely because the noise amplifier i...

AI Technical Summary

Problems solved by technology

[0004] However, on the one hand, both inductors and capacitors are in the form of passive devices, which will consume more layout area; on the other hand, inductors and capacitors are usually two independent devices, that is to say, in integrated circuit design, the inductor Can only be used for inductive components, and capacitors can only be used for capacitive components, the two are not interoperable

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