RT9228
Advanced PWM and Dual Fixed Linear Power Controller
General Description
The RT9228 is a 3-in-one power controller optimized for
high-performance microprocessor and computer
applications. The IC integrates a synchronous buck PWM
controller, a linear regulator, and a linear controller as well
as monitoring and protection functions into a 24-pin SOP
package. The PWM controller regulates the
microprocessor core voltage. The linear regulator
provides power for the clock driver circuit and the linear
controller regulates power for the GTL bus.
The RT9228 features an Intel-compatible, TTL 5-bit
programmable DAC that adjusts the core voltage from
2.1V to 3.5V in 0.1V increments and from 1.3V to 2.05V
in 0.05V steps. The 5-bit DAC has a typical
±
1% tolerance.
The linear regulator uses an internal drive device to
provide 2.5V
±
2.5% output voltage. The linear controller
drives an external N-Channel MOSFET or a low cost NPN
bipolar transistor to provide 1.5V
±
2.5%.
The RT9228 monitors all the output voltages. A Power-
good signal is issued when the core voltage is within
±
10%
of the DAC setting and the other levels are above their
under-voltage levels. Additional build-in over-voltage
protection for the core output uses the lower MOSFET to
prevent output voltage above 115% of the DAC setting.
The PWM over-current function monitors the output
current using the voltage drop across the upper
MOSFET's R
DS(ON)
, which eliminates the need for a
current sensing resistor.
Features
3-in-one Regulated Voltages for Microprocessor
Core, Clock, and GTL
Compatible with HIP6016
Power-good Output Voltage Monitor
Switching Section
5-bit DAC Programmable from 1.3V to 3.5V
±
1% DAC Accuracy
Fast Transient Response
Full 0% to 100% Duty Cycle Driver
Fixed 200kHz Switching Frequency
Adaptive Non-Overlapping Gate Driver
Over-Current Monitor Uses MOSFET R
DS(ON)
Over-Voltage Protection Uses Lower MOSFET
Linear Section
Fixed Linear Regulator Output Voltage
MOSFET or NPN Driving Capability
Ultra Fast Response Speed
Under-Voltage Protection
Internal Thermal Shutdown
RoHS Compliant and 100% Lead (Pb)-Free
Applications
Full Motherboard Power Regulation for Computer
Low-voltage Distributed Power Supplies
Pin Configurations
(TOP VIEW)
VCC
VID4
VID3
VID2
VID1
VID0
PGOOD
FAULT
SS
NC
FB2
VIN2
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
UGATE1
PHASE1
LGATE1
PGND
OCSET1
VSEN1
FB1
NC
FB3
GATE3
GND
VOUT2
Ordering Information
RT9228
Package Type
S : SOP-24
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
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.
DS9228-06 March 2007
SOP-24
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
