HW/SW Codesign Project PWM Control IC 曾任輝 林柏丞
Outline Buck Converter PWM IC A/C Converter PID regulator DPWM Simulation Summary
Buck Converter
PWM Control IC Block
IC Function A/D-----A complete analog controller could be simpler than a high-speed high-resolution A/D. PID regulator Available microcontroller/DSP systems are still too complex and costly. DPWM-----High-speed/ High-resolution digital pulse width modulators are needed.
Proper Resolution for A/D
PID regulator Control law for PID regulator : d[n]=d[n-1]+ae[n]+be[n-1]+ce[n- 2]
DPWM resolution
DPWM
Behavior description for a buck switching converter by MATLAB/SIMULINK
Simulation Result Change of the output voltage (top) for the change of output current from 0.3A to 1A output voltage is regulated at 1.5v for a 3.3v input voltage
Summary Through loop analysis for the entire system, tune the parameters of the PID regulator to meet the loop bandwidth or adequate phase margin. Under a specification of the regulator, select the proper resolution of ADC and DPWM to avoid “limit cycling”. Supply regulator are widely used in communication, computer, consumer products.