Adaptive Variable Bandwidth Phase Locked Loop

Abstract

The invention discloses a self-adaptive variable-bandwidth phase-locked loop comprising a phase-locked loop circuit, a self-adaptive control circuit and a threshold voltage generating circuit. The self-adaptive control circuit is used for detecting control voltage of a voltage-controlled oscillator and outputting a first detecting signal and a second detecting signal. The first detecting signal and the second detecting signal are inputted into a phase-locked loop circuit and automatically select work frequency ranges of the phase-locked loop circuit. By respectively controlling a current source of a charge pump, parameters of a low-pass filter and load of a delay unit of the voltage-controlled oscillator via the first detecting signal and the second detecting signal outputted by the self-adaptive control circuit, the bandwidth of the phase-locked loop circuit can be automatically optimized.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit, in particular to an adaptive variable bandwidth phase-locked loop. Background technique [0002] The phase-locked technology is generally implemented by a phase-locked loop circuit (Phase Locked Loop, PLL), which has been proposed for nearly 100 years, and is widely used in electronic systems, and at the same time, the performance requirements are getting higher and higher. Existing PLL chips are developing in the direction of high frequency, wide frequency band, large integration, low power consumption, low price, and powerful functions. Existing phase-locked loops are all optimized and designed structures based on specific frequency ranges, and segmental bandwidth optimization cannot be performed within the range of the entire data stream. [0003] Such as figure 1 Shown is the structural block diagram of the existing phase-locked loop. The existing phase-locked loop includes a frequency...

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