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

Abstract

An analog-to-digital converter sampling system, comprising: a switch tube; an analog-to-digital converter; a microprocessor, including a first PWM module and a second PWM module, the first PWM module is connected to the switch tube, and the second A PWM module is used to generate a first PWM signal to drive a switch tube, the second PWM module is connected to the analog-to-digital converter, and the second PWM module is used to generate a signal with a phase difference from the first PWM signal. The second PWM signal triggers the analog-to-digital converter to perform analog-to-digital conversion, so that the sampling time of the analog-to-digital converter corresponds to a certain fixed point in the first PWM signal period, thereby realizing fixed-point sampling of the analog-to-digital converter .

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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