Unit gain regenerative integrator with changeable integration rate and clock-recovery circuit

Abstract

The invention provides a unit gain regenerative integrator with a changeable integration rate and a clock-recovery circuit. The integrator comprises a charge injection circuit and a bootstrapping circuit. An input end of the charge injection circuit is connected with an input signal, a differential control end is connected with an external current control signal, and an output end of the charge injection circuit is connected with an input end of the bootstrapping circuit. The bootstrapping circuit comprises an integrating capacitor, the input signal passes through the charge injection circuit and then outputs charges and the charges are stored to the integrating capacitor, the charges are output integrated results of the integrating capacitor in the mode of a voltage signal from the input end of the bootstrapping circuit, through the regulation of the external current control signal, the current size of the charge injection circuit is controlled, and the integration rate is changed. The integrator uses regenerative feedback of the unit gain, a value of the integrating capacitor is not needed to be changed, change of the integration rate is achieved, through a control end, the fact that a larger integration rate exists at a frequency capturing stage so that locking time is shortened, and a smaller integration rate exists at a phase tracking stage so that better stability of loop circuit is achieved.

Description

technical field [0001] The invention belongs to the field of integrators, in particular to a unit gain positive feedback integrator with variable integration rate and a clock recovery circuit. Background technique [0002] The main function of an integrator is that the output signal is equal to the time integral of the input signal. The main performance parameters of the integrator are the integration rate and the ability to maintain the integral value. For the capacitive integrator, the charging current and the capacitance determine the integration rate, and the leakage current on the capacitance determines the ability of the integrator to maintain the integration result. [0003] Capacitive integrators use capacitors to store and hold charge. A typical integrator is implemented by an op amp through negative feedback with a gain close to infinity. However, high open-loop gain requires better compensation to ensure the stability of the op amp. This compensation is difficu...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the embodiments of the present invention is to provide a unit gain positive feedback integrator with variable integration rate, aiming to solve the problem of poor stability caused by negative feedback of traditional integrators

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