RT9243 Datasheet, PDF (1/18 Pages) Richtek Technology Corporation – Multi-Phase PWM Controller for CPU Core Power Supply

RT9243
Multi-Phase PWM Controller for CPU Core Power Supply
General Description
The RT9243 is a multi-phase buck DC/DC controller
integrated with all control functions for GHz CPU VRM.
The RT9243 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.
RT9243 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,
V_CORE 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 RT9243 supports VRD10.x by 6-bit
V_ID input, precise initial value & smooth V_CORE transient
at VI_ID jump. The IC monitors the V_CORE 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
RT9243
Package Type
S : SOP-32
Note :
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
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.
DS9243-07 March 2007
Features
z Multi-Phase Power Conversion with Automatic
Phase Selection
z VRD10.x 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 Intel^® Processors Voltage Regulator: VRD10.x
z Low Output Voltage, High Current DC-DC Converters
z Voltage Regulator Modules
Pin Configurations
OVP
PGOOD
VID4
VID3
VID2
VID1
VID0
VID125
VOSS
ADJ
SS
FB
COMP
VDIF
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
RT
DVD
VCC
PWM4
ISP4
ISP2
PWM2
PWM1
ISP1
ISP3
PWM3
GND
SGND
VSEN
ISN1
ISN2
www.richtek.com
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