Spread-spectrum clock generating circuit

Abstract

The invention provides a spread-spectrum clock generating circuit. The spread-spectrum clock generating circuit and a wireless communication module are arranged in an electronic device together. The spread-spectrum clock generating circuit comprises a phase-locked loop circuit and a spread-spectrum control circuit, wherein the phase-locked loop circuit comprises a voltage-controlled oscillator; the voltage-controlled oscillator is used for outputting a spread-spectrum clock signal according to a control voltage; the output frequency of the spread-spectrum clock signal depends on the control voltage; the spread-spectrum control circuit is used for generating control current according to a communication quality parameter of the wireless communication module, and outputting the control current to the phase-locked loop circuit in order to adjust the control voltage by using the control current; and the control voltage is determined according to the control current, so that the spread-spectrum range of the spread-spectrum clock signal is determined according to the communication quality parameter.

Description

technical field [0001] The present invention relates to a spread-spectrum clock generator (SSCG: spread-spectrum clock generator), in particular to a programmable charge pump spread-spectrum clock generating circuit. Background technique [0002] With the rapid development of the electronic circuit industry, the operating frequency of electronic components is increasingly accelerated, thus causing the problem of electronic magnetic interference (EMI). In other words, the high-frequency electromagnetic noise interference caused by the clock signal has become an issue that cannot be ignored. Electromagnetic noise interference will not only affect the stability of the circuit, but may also interfere with other electronic components around. The main sources of EMI are usually system clocks, such as clock generators, crystal oscillators, voltage-controlled oscillators, and phase-locked loops. Especially, for an electronic device that emphasizes the quality of wireless communica...

AI Technical Summary

Problems solved by technology

Once the designer decides the spread spectrum range, the traditional spread spectrum clock generator can only run uninterruptedly with a fixed spread spectrum range, and the jitter phenomenon of the clock signal will continue to occur

Images