RT9218
5V/12V Synchronous Buck PWM DC-DC and Linear Power
Controller
General Description
The RT9218 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.
Features
Operating with 5V or 12V Supply Voltage
Drives All Low Cost N-MOSFETs
Voltage Mode PWM Control
300kHz Fixed Frequency Oscillator
Fast Transient Response :
High-Speed GM Amplifier
Full 0 to 100% Duty Ration
Internal Soft-Start
Power Good Indicator
Adaptive Non-Overlapping Gate Driver
Over-Current Fault Monitor on MOSFET, No Current
Sense Resistor Required
Specific power good indicator for Intel®
Grantsdale FSB_VTT power sequence
RoHS Compliant and 100% Lead (Pb)-Free
Applications
Graphic Card
Motherboard, Desktop Servers
IA Equipments
Telecomm Equipments
High Power DC-DC Regulators
Ordering Information
RT9218
Package Type
S : SOP-14
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Pin Configurations
(TOP VIEW)
BOOT
UGATE
GND
LGATE
DRV
NC
NC
2
3
4
5
6
7
14
13
12
11
10
9
8
PHASE
OPS
FB
VCC
PGOOD
FBL
NC
Note :
RichTek Pb-free and Green products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
100% matte tin (Sn) plating.
SOP-14
DS9218-08 March 2007
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
