Synchronous oscillator circuit

Abstract

The invention relates to a synchronous oscillator circuit which forces synchronization according to an external input synchronous signal. The invention discloses the synchronous oscillator circuit for solving the problems associated with frequency, such as electromagnetic interference, switch noise of the circuit, and the problem of improving the stability of clock signal of the circuit. The technical scheme is as follows: the synchronous oscillator circuit comprises a first comparator, a second comparator, a third comparator, a synchronous control circuit, an SR latch, an NMOS (N-channel Metal Oxide Semiconductor) tube, a resistor and a capacitor. The synchronous oscillator circuit in a work mode of controlling inner frequency of the circuit by the external period signal has the characteristic of high stability, and can solve the problems associated with frequency, such as the electromagnetic interference and the switch noise of the circuit,. The circuit has the characteristics of simple structure, easiness in transplanting and adjustability of external frequency, and can be widely applied to various functional circuits, and in particular to a switch power supply to reduce interference to the circuit when the switch power supply works at certain frequency.

Description

technical field [0001] The invention relates to integrated circuit technology, in particular to a synchronous oscillator circuit forcibly synchronous according to an external input synchronous signal. Background technique [0002] In electronic systems, the role of the oscillator is usually to provide a clock signal for the circuit system, coordinate the dynamic work of the circuit system, and is an indispensable power module. [0003] Traditional oscillator circuits such as figure 1 As shown, the capacitor C is the charging and discharging capacitor, R is the current limiting resistor, the upper threshold voltage VTH+ and the lower threshold VTH- are the reference voltages of the comparator COMP1 and the comparator COMP2 respectively. The oscillator compares the voltage on the capacitor C with the two reference voltages VTH+ and VTH- of the comparator, periodically changes the state of the SR latch, controls the turn-on and turn-off of the NMOS transistor MN1, and forms an...

AI Technical Summary

Problems solved by technology

[0004] However, usually different components in an electronic system have their own specific frequency oscillators, resulting in problems such as intermodulation interference, electromagnetic interference (EMI), and difference frequency noise in the system, which seriously affect the overall performance of the electronic system

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