Abstract The main disadvantages of converter with a digital PWM controller are slower transient response and output voltage quantization error. This paper deals with these problems and one solution of digital adaptive feedback control is proposed.
The adaptive feedback control is based on the Digitally Controlled Continually Variable Slope Delta Modulation principle. The PWM duty cycle change is proportional to the difference of two neighboring output voltage samples. The value of the duty cycle change is proportional to the slope of output voltage change. A step of duty cycle change is digitally controlled by 4 bit algorithm, so each step has one of 16 discrete values.
In this paper the comparative analyses of classic PWM converter and digital converter with uniform quantization, is described. Both converters operate at the same switching frequency and have the same loop bandwidth. A new approach of the adaptive drive signals generation is suggested with algorithm for declination of disadvantages of digital converter with uniform quantization. This type of converter is called Digital Converter with Adaptive Feedback Control.
Key words: DC/DC converter, pulse width modulation, delta modulation, digital converter, adaptive feedback control.