SLVSAA4G June 2010 – February 2018 TPS65251
Buck 1 has a low conduction resistance compared to Buck 2 and 3. Normally Buck 1 is used to drive higher system loads. Buck 2 and 3 are used to drive some peripheral loads like I/O and line drivers . The combination of loads from Buck 2 and 3 may be on par with the load of Buck 1. To reduce input ripple current, Buck 2 operates in phase with Buck 3; Buck 1 and Buck 2 operate 180° out-of-phase. This enables the system, having less input ripple, to lower component cost, save board space and reduce EMI.