Oscillator circuit

Abstract

The present invention relates to an oscillator circuit, and comprises a cross transistor pair circuit, an active load circuit, a current source, a differential transistor pair circuit, a first sourceelectrode random coupling circuit, and a second source electrode random coupling circuit. The cross transistor pair circuit comprises a grid electrode and a drain electrode, which are connected with each other and are respectively provided with a first transistor with a first output and a second transistor with a second output; an output voltage is arranged between the first output and the secondoutput; the active load circuit is connected with the drain electrodes of the first transistor and the second transistor; the current source is connected with a grounding end and is coupled with a fixed voltage so as to provide current; the differential transistor pair circuit comprises a first differential input and a second differential input, and is used for connecting the source electrodes ofthe first transistor and the second transistor and the current source; the first source electrode random coupling circuit is connected with the first output and the first differential input; the second source electrode random coupling circuit is connected with the second output and the second differential input; the first source electrode random coupling circuit and the second source electrode random coupling circuit respectively comprises a load transistor which is used for receiving a modulation voltage and changing the delay time of the oscillator circuit.

Description

【Technical field】 [0001] The present invention relates to an oscillator circuit, and in particular to an oscillator circuit that changes a delay time through a modulation voltage. 【Background technique】 [0002] An oscillator circuit is a circuit with a wide range of applications. For example, the transponder module widely used in radio frequency identification (RFID) systems such as leisure cards and access control chip cards requires an oscillator circuit for sensing. The most basic oscillator circuit is composed of inductance components, but in practice, because the inductor occupies a large area, it will undoubtedly cause negative effects for the increasingly smaller integrated circuit size. [0003] The use of the Ring-type oscillator makes the area much smaller than the oscillator composed of inductive components. However, the condition for the oscillator to start oscillating is that the loop phase offset must be an integral multiple of 360 degrees, and the loop gain...

AI Technical Summary

Problems solved by technology

However, the conditions for the oscillator to start up must be such that the loop gain must be greater than 1 in addition to the loop phase offset being an integer multiple of 360 degrees.

Therefore, in order to make the gain greater than 1, the operating frequency range of the oscillator circuit is limited and cannot be greatly changed.

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