ZHCSTC5B October 2023 – June 2024 LM51772
PRODUCTION DATA
The device features a dynamic voltage scaling, in case the output voltage register gets programmed during the converter is in operation. It shall avoid any excessive current and voltage spike as the control loop bandwidth is set by external components. If the output voltage target gets programmed in the converter off state the soft-start will ramp to newly programmed target voltage.
Once the VOUT_A field of the register is changed the reference voltage will slowly change-over to the new target value. The rising and falling slew rate shall not exceed the defined ∆Vo(DVS) within the time td(DVS) the slope time is programmable via NVM setting.
If the converter operates in PSM, the inductor current cannot go to negative values. The device features a passive and a active DVS configuration, selectable via NVM setting. If passive DVS is selected the Vo slope of the system will not follow the defined DVS slew rates as the output capacitor can only be discharged passively via the output load. If active DVS is selected the internal output discharge is active during the negative ramp of the DVS. The maximum discharge current is used for the active DVS setting, independently of the register selection of the discharge strength. The output capacitor voltage can follow the reference as long as the capacitor is selected to match the maximum discharge current for the selected DVS ramp speed.