ZHCSKX0 February 2020 TPS59632-Q1
PRODUCTION DATA.
When the transient load increase becomes quite large, it is difficult to meet the energy demanded by the load especially at lower input voltages. Then it is necessary to quickly increase the energy in the inductors during the transient load increase. This increase is achieved by enabling pulse overlapping. In order to maintain the interleaving of the multi-phase configuration while maintaining pulse-overlapping during load-insertion, the undershoot reduction (USR) mode is entered only when necessary. This device enters this mode is when the difference between DROOP voltage and ISUM voltage exceeds the USR voltage level specified in the Electrical Characteristics table.
Figure 14 shows the undershoot reduction operation. This feature allows for the use of reduced output capacitance while continuing to meet the specification. The device achieves undershoot reduction by overlapping of pulses on all the phases.
Figure 14. Undershoot Reduction When the transient condition is completed, the interleaving of the phases is resumed.
It should be noted that single-phase mode there is no USR mode of operation.