Digital pulse width modulation controlling system and method

A digital pulse width modulation (DPWM) controlling method for controlling a load of an application circuit with a DPWM unit, comprising the following steps:

• receiving a sense signal detected from the load and a reference signal;
• comparing the sense signal and the reference signal to output an analog comparison signal;
• counting a respective number of times of a high level and a low level occurring on the analog comparison signal, respectively, whenever the sense signal is within a stable duration;
• generating a portion of the DPWM signal having a specific pulse width according to the number of times of the high level and the low level whenever the sense signal is within a stable duration;
• and
• repeating the counting and generating steps to obtain a plurality of portions of the DPWM signal to output continuously the DPWM signal by combining the plurality of portions of the DPWM signal.