The RT9218B is a dual output with one synchronous buck
PWM and one linear controller. The part is proposed to
generate logic-supply voltages for PC based systems. The
high-performance device includes internal soft-start,
frequency-compensation networks, power good signaling
with specific sequence, and it comes all of the logic control,
output adjustment, power monitoring and protection
functions into a small footprint package. The part is
operated at fixed 300kHz frequeny providing an optimum
compromise between efficiency, external component size,
and cost. The linear controller is implemented to drive an
external MOSFET for regulation and it's adjustable by
setting external resistors. Moreover the specific internal
PGOOD sequence and indicator is also implemented to
conform to Intel? new platform requirement on FSB_VTT
power plane. An adjustable over-current protection (OCP)
is proposed to monitor the voltage drop across the
RDS(ON) of the lower MOSFET for synchronous buck
PWM DC-DC controller.