High-precision and self-adapting relaxation oscillator

Abstract

The invention provides a high-precision and self-adapting relaxation oscillator. The high-precision and self-adapting relaxation oscillator offsets time delay produced by a charge-discharge control circuit arranged in an oscillating circuit according to a capacitor precharging principle, and comprises the oscillating circuit, a first capacitor precharging circuit and a second capacitor precharging circuit, wherein the capacitor precharging circuits are used for precharging a charge-discharge capacitor of the oscillator, the oscillating circuit performs charging and discharging on the basis of precharging level of the capacitor precharging circuits, error time delay produced by the capacitor during two times of charging is offset, so that the oscillator works at preset frequency, and frequency-control current linearity is remarkably improved. The time delay is not reduced by directly increasing speed of a comparator or an RS trigger, the time delay produced by the control circuit and influence of imbalance with external environment change are offset through two times of charging processes, the precision of the oscillator is obviously improved, and the oscillator has quite high temperature stability and power supply rejection, namely, adaptability.

Description

technical field [0001] The invention relates to a relaxation oscillator, in particular to a high-precision self-adaptive relaxation oscillator, which belongs to the technical field of CMOS integrated circuits. Background technique [0002] In large-scale integrated circuits, clock signals are generally generated by oscillators. The relaxation oscillator has a simple structure, low cost, easy integration, and relatively low power consumption. It is the most widely used clock generation circuit in the oscillator. [0003] In the application of signal modulation and demodulation, data recovery of storage system, etc., the control current-frequency of the relaxation oscillator used is required to have a high linearity, so as to reduce distortion and increase the relaxation oscillation frequency range of the device. In the relaxation oscillator, the linearity of the control current-frequency is related to the delay of the control circuit of the oscillation amplitude of the char...

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Problems solved by technology

[0040] Aiming at the problem that the relaxation oscillator can maintain high precision when the external environment changes, the present invention proposes a method of using the principle of capacitor pre-charging to offset the time delay generated by the charge-discharge control circuit, so as to significantly improve the high linearity of frequency-control current Accuracy self-adaptive relaxation oscillator, the relaxation oscillator can still maintain high precision with the change of external environment

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