CCS/TMS320F28035: C2000 Digital Power Supply Workshop Lab4

Hello Jin,

The variable "Vout1SetSlewed" is the reference input to the voltage control loop for output 1.  "Vout1SlewRate" is incrementally added to this in the "A2" task (line 805) in the program.  A2 is one of four time slices triggered by the 1ms event coming from CPU Timer 0 (line 328), so the incremental change to the reference happens every 4ms.  A similar thing happens for the output 2 control loop,

The purpose of slewing the reference is to avoid a sudden change in load current (in lab 4 we are running in peak current mode control), so by ramping the voltage reference to the desired value rather than just stepping to it, we have a smooth change in output voltage without excessive current draw.

Presumably the author chose the increment of 25600 based on the desired value (2093568) and some experimentation.  This combination gives 81 steps, so the ramp time is about 1/3 second.

Regards,

Richard