External RC frequency adjustable oscillator

Abstract

The invention relates to an external RC frequency adjustable oscillator in oscillators. The external RC frequency adjustable oscillator comprises a reference voltage generation circuit 1, a charging circuit 2, a discharge circuit3, and a clock processing circuit 4; the reference voltage generation circuit 1 is used for generating and outputting a reference voltage signal, and the discharge circuit3 is used for discharging charges on the capacitor C2; the discharging circuit 3 comprises a comparator, the charging circuit 2 comprises a capacitor C2, and the voltage on the capacitor C2 is directly fed back to the positive input end of the comparator; and the clock processing circuit 4 is used for enhancing driving and shaping of output. The oscillator is wide in output frequency range, simple in structure, small in area and convenient and flexible to use, and can be widely applied to MCU and other electronic products needing clocks.

Description

technical field [0001] The invention relates to the field of oscillators, in particular to an oscillator with adjustable external RC frequency. Background technique [0002] In traditional applications, the oscillator circuit is implemented with an internal RC circuit and a crystal oscillator circuit. The internal RC circuit generally overcomes the consistency problem between different chips by correcting the circuit, uses temperature compensation to solve the temperature drift problem, and also uses an accurate clock such as a crystal oscillator circuit to perform real-time detection and correction of the clock to improve the accuracy of the chip. [0003] After searching, it was found that the patent application number 201821763559.X is a frequency-adjustable RC oscillator, including a code system conversion module, a bias module, a switch current control module, a comparator, and an output control module. The present invention converts the frequency selection signal into...

AI Technical Summary

Problems solved by technology

[0004]However, the RC circuit inside the oscillator often has relatively large temperature drift, resulting in a decrease in its accuracy, and the frequency is not stable enough and the consistency is poor

[0005] There is an existing solution to overcome the consistency problem between different chips through the correction circuit, and use temperature compensation to solve the temperature drift problem, but the structure of these correction circuits is often more complicated , and the matching of the temperature compensation circuit is poor

[0006] Although the crystal oscillator has the advantages of small clock jitter, small temperature drift and stable frequency, its frequency is relatively single and its production cost is high

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