On the left hand side is an analog controller, comparing it to the digital controller on the right. One of the things to note is that on the left hand side there are a larger number of external components, particularly used in the system when the designer is trying to tailor the control loop and optimise the control loop. Some of the components on the left side that are omitted are components that might be used for conditional sequencing, such as some blue logic externally, that can be done and programmed with the digital power controller on the right. The big difference is that on the right hand side is taking the analog signals and putting them through an ADC (Analog to Digital Converter) so that they can be processed digitally, then have a digital PWM generator through a driver to drive the power stage.