Oscillator circuit with external synchronization function

Abstract

The invention provides an oscillator circuit with an external synchronization function, which belongs to the technical field of electronic circuits. An external resistor is added in the oscillator circuit, and the size of the external resistor is adjusted to adjust the own oscillator frequency. Another synchronous circuit is added. Through a synchronization control signal SYNC, forced synchronization of the oscillator frequency is realized, and a stable and reliable clock signal CLK is acquired. A constant current source is used to discharge an oscillator capacitor, so that the discharge time, namely the high level time of the clock signal CLK, is controllable. The problem that the can not respond, which is caused by too short high level time of the clock signal CLK, is solved. According to invention, the oscillator circuit has the advantages of adjustable oscillation frequency, external synchronization and high stability, and can effectively suppress intermodulation interference, electromagnetic interference and other problems in the circuit.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and in particular relates to an oscillator circuit capable of realizing external synchronization. Background technique [0002] In the field of electronic circuit technology, oscillators are usually used to provide stable and reliable clock signals for system circuits to ensure stable and coordinated work of the circuit system. [0003] Traditional oscillator circuits such as figure 1 shown. The circuit is composed of: a charging and discharging capacitor C0, a current limiting resistor R0, a lower limit comparator COMP1, an upper limit comparator COMP2, an RS latch, and a discharge MOS tube MN0. Among them, the non-inverting input terminal of the lower limit comparator COMP1 is connected to the lower limit threshold voltage Vth_L, the inverting input terminal is connected to the upper plate of the capacitor C0, and the output terminal is connected to the R terminal of the RS latch;...

AI Technical Summary

Problems solved by technology

[0005] but for figure 1 Traditional oscillator circuit, its charging and discharging frequency cannot be controlled

Moreover, since each circuit module in the electronic system has its own unique oscillation frequency, there will be problems such as intermodulation interference and electromagnetic interference in the circuit, which may affect the circuit function in severe cases.

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