SC1544

POWER MANAGEMENT Description Semtech’s SC1544, SC243x and SC1112A or SC1114 provide all the voltages necessary for an ACPI system. The SC1544 offers five independant supplies: a 5V dual supply for USB, a 3.3V dual supply for PCI, a 3.3V or 2.5V dual supply for memory, a 1.5V or 3.3V supply for AGP and a 1.8V supply. The AGP supply is programmble using the system TYPEDET signal. An on-board internal charge pump eliminates the need for P-channel MOS.ETs and enables function from a single 5V supply (system 5VSB). All dual outputs are over current protected. The SC1544 differs from the SC1547 in three important ways: 1) the device initially starts up in S5, and not G0 like the SC1547; 2) the gate drives for the 1.8V and AGP outputs are always high in normal operation; 3) no OCP on the 1.8V and AGP outputs. ACPI Controller for Advanced Motherboards PRELIMINARY .eatures K Complete programmable supply for instantly available K Supports 2.5V memory or 3.3V memory (-2.5 or -3.3 K 5V dual and 3.3V dual supplies are programmable to K Integrated AGP voltage supply with “TYPEDET” signal K K K K K for 3.3V or 1.5V operation Integrated LDO for 1.8V supply Integrated charge pump removes the need for PMOS .ETs, enables single supply operation Over current protection on all dual outputs Inherent soft-start capability TSSOP-24 package be active or inactive in S5 option in part number) PC systems SC1544 Applications K Instantly available motherboards Typical Application Circuit 5V GND 3.3V G...