I'm conducting some research on the Current Programmed Mode control, but i'm confused of the ramp generator submodule.
The range of 280049C DAC value is 0 ~ 4095. The SYSCLK of 280049C is 100MHz, and without any Clock Prescale I set the EPWM Module TBPRD = 2000 which means the frequency of PWM wave is 50kHz.
As stated in the datasheet 16.4.1.'After receiving the selected EPWMSYNCPER signal, the value of RAMPDECVALA. is subtracted from RAMPSTS on every subsequent SYSCLK cycle.'
Now I set RAMPDECVALS = 2. If without any action of compare when the initial value of the most-significant 12 bits of the RAMPSTS is 4080, the Final value is 4080 - 2000*2 = 80?
What if I set RAMPDECVALS = 4 ,without any action of compare when the initial value of the most-significant 12 bits of the RAMPSTS is 4000, the Final value is 0 when TBCTR = 1000?
I pictured what I think above and Do I understand it correctly?
If true, two questions:
1.if when I need a wider range of initial values to respond to sudden changes in my inductor current, and now the most-significant 12 bits of the RAMPSTS is given by a PI controller. Can I say that No matter how fast the controller is , it is saturated by the upper limit of DAC value?
2.If I choose steeper slope compensation , does that mean it limit the range of duty cycle of my converter?
