TIDUEO1B April 2021 – June 2021
The peak current reference command is written to the RAMPMAXREFS which is the starting value of the RAMP used for slope compensation. The slope is decided by RAMPDACVALS. The ramp generator produces a falling-ramp input for the high reference 12-bit DAC when selected. Note that in this mode, the reference 12-bit DAC uses the most significant 12 bits of the RAMPSTS countdown register as its input. The low 4 bits of the RAMPSTS countdown register effectively act as a prescale for the falling-ramp rate configurable with RAMPDECVALA.
In this reference design, The slope is chosen based on two factors: stability and transient response. The empirical value used in the design should make the system stable and also does not sacrifice the transient response. If the slope is too large, it will limit the duty cycle available and will decreases the transient response. If the slope is too small, it will trigger the sub-harmonics oscillation which creates unstable conditions.