Aiming at saving energy, not only the battery-powered application, but all electronic equipment is required to consumption power limit according to each local standard. To save energy, instead of using LDO, switch IC for each circuit block is used after DC/DC converter.
Simple MOSFET can play the role as a switch, but load switch IC can include protection circuits, discharge function at off state, and a slew rate control circuit. As a result, saving space and intensive function realization are possible. Ricoh provides wide variety lineup of switch ICs with low on resistance MOSFET and protection circuits in one chip.