Preliminary
RT9645
5 Channels ACPI Regulator
General Description
The RT9645 is a combo regulator which is compliant to
ACPI specification for desktop/server power management
and system application. The part features one switching
regulator for DDR memory VDDQ power; a second PWM
controller for GMCH core power, a LDO controller for
FSB_ VTT termination, a LDO controller for 5VSB to 3VSB
conversion; and a dual power control 5VDL for S0 and S3
system power.
The part is generally operated to conform to ACPI
specification. In S3 mode, only VDDQ and 3.3VSB
regulators remain on while the FSB_ VTT regulator is off.
In the transition from S3 to S0, an internal SS capacitor is
attached for linear regulators to control its slew rate
respectively to avoid inrush current induced.
RT9645 supports both Intel VR11 and AMD K8 platform.
There is extra control pin VTT_EN to enable FSB_VTT
regulator at AMD K8 mode. This part also implements
PWM1 (V
DDQ
) enabled by release COMP1 at AMD K8
application. This part is assemblyed in the tiny
VQFN-24L 4x4 package.
Features
Integrated 5 Channels Power Regulator
DC/DC Buck PWM Regulator (Driver Included)
DC/DC Buck PWM Controller
Linear Regulator Controller for FSB_VTT Power
3.3VSB Linear Regulator Controller with 40mA
Output Capability
5VDL Switch Control
Conform to ACPI Specification, Supporting Power
Management at S0, S3, and S5 State
300kHz Fixed Frequency Oscillator
Low-Side R
DS(ON)
Current Sensing for Precision
Over-Current Detection
Thermal Shutdown
Small 24-Lead VQFN Package
RoHS Compliant and 100% Lead (Pb)-Free
Applications
Desktop System Power
Server System Power
Pin Configurations
Ordering Information
RT9645
SB5V_DRV
20
(TOP VIEW)
SB3V_SEN
VCC_DRV
Package Type
QV : VQFN-24L 4x4
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.
S3
24
23
22
S5
21
SB3V_DRV
VDD
PWM2
SS2/EN2
COMP2
FB2
GND
19
18
17
16
1
2
3
4
5
6
7
8
9
10
11
25
12
VTT_DRV
VTT_SEN
VTT_EN
ISNS2
FB1
COMP1
PGND
15
14
13
BOOT
ISNS
PHASE
PVIN
VQFN-24L 4x4
DS9645-00 August 2007
UGATE
LGATE
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
