RT9643 Datasheet, PDF (1/17 Pages) Richtek Technology Corporation – 5 Channel ACPI Regulator with Step-Down DC/DC Controller

RT9643
5 Channel ACPI Regulator with Step-Down DC/DC Controller
General Description
The RT9643 is a combo regulator which is compliant to
ACPI specification for desktop/motherboard power
management and system application. The part features
one switch regulator for DDR memory VDDQ power; three
linear regulators including 1.5Amp peak sourcing/sinking
capability regulator for DDR VTT, a 1.2V ultra-low-dropout
linear controller for chipset miscellaneous power, a 3.3VSB
power with 1.25Amp peak current capability; and 2 dual
power control including 5VDL, and 3.3VDL control for S3
and S5 system power. The part totally feature 5 sets power
which are compliant to ACPI specification into a single
small footprint package VQFN-24L 5x5.
The part is generally operated to conform to ACPI
specification, in S3 state, there are only VDDQ and
3.3VSB regulators remain on while the VTT and ULDO
regulators are off. In the transition from S3 to S0, an
external SS capacitor is attached for linear regulators to
control its slew rates respectively to avoid inrush current
induced. Moreover, the PGOOD signal raises high in S0
stage while all 3 regulators go stable. In the stage of S5
(EN = 0), there only 3.3VSB LDO remain on, while the
other regulators are powered down. The VDDQ PWM
regulator is a voltage mode implementation with external
compensation to provide high load transient response. The
VTT is regulated to follow 1/2 of VDDQ and is capable of
sourcing or sinking 1.5A peak currents.
Ordering Information
RT9643
Package Type
QV : VQFN-24L 5x5 (V-Type)
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.
DS9643-03 August 2007
Features
z Integrated 5 Channels Power Regulator
`DC/DC Buck PWM Regulator for V_DDQ (2.5V or 1.8V)
`Linear Regulator Supports 1.5Amp Peak Sinking/
Sourcing Capability for VTT
` 1.2V Ultra-Low-Dropout Linear Controller for
GMCH VTT Power
`3.3VSB Linear Regulator Supports 1.25A Capability
`5VDL Switch Control
`3VDL Switch Control
z Conform to ACPI Specification
`Support Power Management at S0, S3, and S5
State
z 300kHz Fixed Frequency Switching
z R_DS(ON) Current Sensing or Optional Current
Sense Resistor for Precision Over-Current Detect
z Embedded Synchronous Boot-Strapped Diode
z Power Good Signal Indication for All Voltages
z Thermal Shutdown
z 24-Lead VQFN Package
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z DDR VDDQ and VTT Voltage Generator with ACPI
Support
z Desktop System Power
z Servers System Power
Pin Configurations
(TOP VIEW)
1.2V_DRV 1
1.2V_FB 2
5VSB_DRV 3
5V_MAIN 4
VTT_SNS 5
VTT_OUT 6
24 23 22 21 20 19
GND
25
18 EN
17 S3#I
16 VCC_EN
15 3VSB_OUT
14 VCC
13 PGOOD
7 8 9 10 11 12
VQFN-24L 5x5
www.richtek.com
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