Method and device for extending controller PWM resolution

The present invention is applicable to the field of the PWM control, discloses a method and apparatus for PWM resolution expansion controller, the method comprising: reading a current value of actual analog; obtaining the analog value set in advance; a current analog the amount of the actual value is compared with a preset value of the analog; if the actual value of the current analog value is less than a predetermined analog, the analog current increasing direction to adjust the amount of extension of the software PWM duty cycle; if the actual value of the current analog value of the analog amount is larger than preset, the current decreasing direction to adjust the analog extension software PWM duty cycle. The present invention without reducing the PWM frequency of the PWM very effectively extends the resolution, to meet the needs fine control applications, since the high frequency controller is not used, the system can effectively reduce power consumption and cost.