Crystalless Clock Generation System for Broadcast SoC

Abstract

The invention provides a no-crystal clock generation system of a broadcast system-on-chip. The system comprises a high-frequency inductor-capacitor digital control oscillator, a first frequency divider, a frequency divider group, an analog phase-locked loop, a second frequency divider, a receiver and a digital signal processor. The first frequency divider is used for producing and outputting a reference clock of the analog phase-locked loop; the frequency divider group is used for producing and outputting various different digital clocks; the analog phase-locked loop is used for receiving the reference clock and generating oscillation frequency; the second frequency divider is used for carrying out frequency division on the frequency output by the analog phase-locked loop and generating needed local oscillating frequency; and the digital signal processor is used for receiving and analyzing the signal frequency output by the receiver to obtain frequency deviation of the local oscillating frequency and the received signal frequency, and the high-frequency inductor-capacitor digital control oscillator is adjusted based on the frequency deviation. According to the no-crystal clock generation system, the clock needed in a chip can be realized without off-chip crystal, and stable frequency output can be achieved.

Description

technical field

[0001] The invention belongs to the technical field of integrated circuit design, and relates to a clock generating system, in particular to a crystalless clock generating system of a broadcast system chip. Background technique

[0002] The development direction of modern integrated circuits is high integration, which is to integrate systems that originally required multiple devices into one chip. These revolutionary chips have brought rapid changes to our lives, and each of us is enjoying the convenient life brought by technology. With the improvement of integration level, the devices that are still relatively difficult to integrate include power amplifier (PA), antenna switch (antenna switch), SAW filter (SAW filter) and crystal. Especially for crystals, people have made a lot of efforts to integrate the functions of crystals into chips in the past fifteen years. But simple integration cannot replace the stable frequency output of the crystal, so in order...

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