Analog-to-digital converter sampling system and analog-to-digital converter sampling method

Abstract

The invention relates to an analog-to-digital converter sampling system. The system includes a switching tube, an analog-to-digital converter and a microprocessor; the microprocessor includes a first PWM module and a second PWM module; the first PWM module is connected with the switching tube; the first PWM module is used for generating first PWM signals for driving the switching tube; the second PWM module is connected with the analog-to-digital converter; and the second PWM module is used for generating second PWM signals which have phase difference with the first PWM signals, so as to trigger the analog-to-digital converter to perform analog-to-digital conversion, and therefore, the time point of the sampling of the analog-to-digital converter is corresponding to a certain fixed point within the period of the first PWM signals, and the fixed-point sampling of the analog-to-digital converter can be realized.

Description

technical field [0001] The invention relates to an analog-to-digital converter sampling system and an analog-to-digital converter sampling method. Background technique [0002] In the application field of digital DC / DC converters, ADC (Analog Digital Converter) is an essential module for every system. At present, most MCUs of embedded systems have embedded high-speed ADC peripherals. These high-speed ADC peripherals Cooperating with the high-speed and high-resolution PWM module of MCU, the digital power supply has been rapidly developed in the fields of communication and industrial control. However, these high-speed ADC peripherals, due to the influence of the high-speed switching of the PWM (Pulse Width Modulation, pulse width modulation) module, the ADC sampling value will have a large jitter, and the jitter of these sampling values ​​will cause the entire digital feedback loop. The instability will increase the output ripple of the whole machine and deteriorate the syste...

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Problems solved by technology

However, these high-speed ADC peripherals, due to the influence of the high-speed switching of the PWM (Pulse Width Modulation, pulse width modulation) module, the ADC sampling value will have a large jitter, and the jitter of these sampling values ​​will cause the entire digital feedback loop. The instability of the system will increase the output ripple of the whole machine and deteriorate the system stability. For the digital control network based on the current loop, if fixed-point sampling cannot be performed, the system will almost collapse.

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