Built-in oscillation circuit

Abstract

The invention provides a built-in oscillation circuit. A negative feedback closed loop circuit type is adopted for the built-in oscillation circuit, and a frequency-voltage conversion mode is used for the built-in oscillation circuit, and therefore the built-in oscillation circuit is enabled to be completely integrated in a chip, crystal oscillators needing to be additionally arranged are saved, and process cost is saved. An oscillation frequency generated by an annular oscillator is converted into a feedback voltage and compared with a reference voltage, then compared results are fed back to a control end of the annular oscillator, the frequency of the annular oscillator is changed, the output frequency deviation is compensated, and therefore work frequency with low temperature drift is output by a loop circuit, and output frequency with high precision is generated.

Description

technical field [0001] The invention relates to an oscillating circuit device, in particular to a built-in oscillating circuit. Background technique [0002] With the rapid development of science and technology, the development of various devices tends to be low power consumption, small area and low cost, and the precise clock generation circuit also tends to be integrated on a chip, with high precision and high frequency. Oscillator circuits are commonly used to provide clock signals to various integrated circuit chips. Generally, the oscillator circuits that provide clock signals to various circuit chips are as follows: [0003] One is a generation circuit based on a ring oscillator. The ring oscillator generating circuit is widely used, but in the CMOS process, due to the instability of temperature, process and power supply voltage, the output frequency stability of the on-chip integrated clock circuit is relatively poor. [0004] The other is the RC relaxation (Relaxa...

AI Technical Summary

Problems solved by technology

This oscillator circuit can achieve very high precision (1-100ppm), but this solution requires an additional external crystal oscillator, which not only greatly increases the cost of the product, but also requires a large chip area and power co

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