RT9641A/RT9641B pdf datasheet

The RT9641A/B, paired with either the RT9230 or RT9231
simplifies the implementation of ACPI-compliant designs
in microprocessor and computer applications. The IC
integrates two linear controllers and a low-current pass
transistor, as well as the monitoring and control functions
into a 16-pin SOIC package. One linear controller generates
the 3.3VDUAL voltage plane from an ATX power supply's
5VSB output during sleep states (S3,S4/S5), powering
the PCI slots through an external pass transistor, as
instructed by the status of the 3.3VDUAL enable pin. An
additional pass transistor is used to switch in the ATX
3.3V output for PCI operation during S0 and S1 (active)
operating states. The second linear controller supplies
the computer system's 2.5V/3.3V memory power through
an external pass transistor in active states. During S3
state, an integrated pass transistor supplies the 2.5V/
3.3V sleep-state power. A third controller powers up a
5VDUAL plane by switching in the ATX 5V output in active
states, or the ATX 5VSB in sleep states.