RT8867A Datasheet, PDF (1/21 Pages) Richtek Technology Corporation – Advanced 4/3-Phase PWM Controller for CPU Core Power

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RT8867A
Advanced 4/3-Phase PWM Controller for CPU Core Power
General Description
The RT8867A is an advanced 4/3-phase synchronous buck
controller with 3 integrated MOSFET drivers. It integrates
an 8-bit DAC that supports Intel VR11.x CPUs power
application.
The IC adopts state-of-the-art dynamic phase control
capability by PS1/2/3 pins and achieves high efficiency
over a wide load range. It uses lossless R_DS(ON) current
sensing to achieve phase current balance. Other features
include adjustable operating frequency, adjustable soft-
start, short circuit protection, adjustable over current
protection, over voltage protection, under voltage
protection, power good indication, VR_HOT indication and
VR_SHDN indication.
The RT8867A is available in a small footprint with WQFN-
48L 6x6 package.
Ordering Information
RT8867A
Package Type
QW : WQFN-48L 6x6 (W-Type)
Note :
Lead Plating System
Z : ECO (Ecological Element with
Halogen Free and Pb free)
Richtek 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.
Marking Information
RT8867A
ZQW
YMDNN
RT8867AZQW : Product Number
YMDNN : Date Code
Features
z 12V Power Supply Voltage
z 4/3-Phase Power Conversion
z Integrated 3 MOSFET Drivers with Internal
Bootstrap Diode
z Dynamic Phase Control Capability
z 8-bit DAC Supports Intel VR11.x CPUs
z Lossless R_DS(ON) Current Sensing for Current Balance
z Adjustable Frequency : 50kHz to 1MHz
z Adjustable Over Current Protection
z Adjustable Soft-Start
z VR_RDY, VR_HOT and VR_SHDN Indications
z Small 48-Lead WQFN Package
z RoHS Compliant and Halogen Free
Applications
z Desktop CPU Core Power
z Middle/High End Graphic Cards
z Low Voltage, High Current DC/ DC Converters
Pin Configurations
(TOP VIEW)
48 47 46 45 44 43 42 41 40 39 38 37
PS2 1
SS 2
EN 3
DAC 4
EAP 5
FB 6
COMP 7
CSP 8
CSN 9
IMAX 10
PS3/VR_SHDN 11
PS1 12
36
35
34
33
32
GND
31
30
29
28
49
27
26
25
13 14 15 16 17 18 19 20 21 22 23 24
UGATE1
PHASE1
LGATE1
VCC12A
BOOT2
UGATE2
PHASE2
LGATE2
VCC12B
LGATE3
PHASE3
UGATE3
Copyright ©2012 Richtek Technology Corporation. All rights reserved.
DS8867A-01 August 2012
WQFN-48L 6x6
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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