RT9244 Datasheet, PDF (1/15 Pages) Richtek Technology Corporation – Multi-Phase PWM Controller for CPU Core Power Supply

RT9244
Multi-Phase PWM Controller for CPU Core Power Supply
General Description
The RT9244 is a multi-phase buck DC/DC controller
integrated with all control functions for GHz CPU VRM.
The RT9244 controls 2, 3 or 4 buck switching stages
operating in interleaved phase set automatically. The multi-
phase architecture provides high output current while
maintaining low power dissipation on power devices and
low stress on input and output capacitors. The high
equivalent operating frequency also reduces the component
dimension and the output voltage ripple in load transient.
RT9244 controls both voltage and current loops to achieve
good regulation, response & power stage thermal balance.
Precise current loop using R_DS(ON) as sense component
builds precise load line for strict VRM DC & transient
specification and also ensures thermal balance of different
power stages. The settings of current sense, droop tuning,
VCORE initial offset and over current protection are
independent to compensation circuit of voltage loop. The
feature greatly facilitates the flexibility of CPU power supply
design and tuning.
The DAC output of RT9244 supports K8 CPU by 5-bit VID
input, precise initial value & smooth VCORE transient at VID
jump. The IC monitors the VCORE voltage for PGOOD and
over-voltage protection. Soft-start, over-current protection
and programmable under-voltage lockout are also provided
to assure the safety of microprocessor and power system.
Ordering Information
RT9244
Package Type
S : SOP-32
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.
Features
z Multi-Phase Power Conversion with Automatic
Phase Selection
z K8 DAC Output with Active Droop Compens-ation
for Fast Load Transient
z Smooth V_CORE Transition at VID Jump
z Power Stage Thermal Balance by R_DS(ON) Current
Sense
z Hiccup Mode Over-Current Protection
z Programmable Switching Frequency (50kHz to
400kHz per Phase), Under-Voltage Lockout and
Soft-Start
z High Ripple Frequency Times Channel Number
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z AMD^® Athlon^TM 64 and Opteron^TM Processors Voltage
Regulator
z Low Output Voltage, High Current DC-DC Converters
z Voltage Regulator Modules
Pin Configurations
SS
OVP
VID4
VID3
VID2
VID1
VID0
VOSS
COMP
FB
ADJ
VDIF
VSEN
SGND
ISN4
ISN3
(TOP VIEW)
32
2
31
3
30
4
29
5
28
6
27
7
26
8
25
9
24
10
23
11
22
12
21
13
20
14
19
15
18
16
17
SOP-32
DVD
RT
PGOOD
PWM4
ISP4
ISP1
PWM1
PWM2
GND
ISP2
ISP3
PWM3
VCC
SS2
ISN1
ISN2
DS9244-06 March 2007
www.richtek.com
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