RT9241A Datasheet, PDF (1/17 Pages) Richtek Technology Corporation – Two-Phase DC/DC Controller for CPU Core Power Supply

RT9241A/B
Two-Phase DC/DC Controller for CPU Core Power Supply
General Description
The RT9241A/B is a two-phase buck DC/DC controller
integrated with all control functions for high performance
processor VRM. The RT9241A/B drives 2 buck switching
stages operating in 180 degree phase shift. The two-
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.
RT9241A/B regulates both easily set voltage and current
loops. Precise current sharing for power stage is achieved
by differential input current sense and processing circuit.
The settings of current sense, droop tuning 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 RT9241A/B uses a 5-bit DAC of 1.1V to 1.85V
(25mV/step) output with load current droop compensation
to meet the strict VRM transient requirement. 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
RT9241A/B
Package Type
S : SOP-20
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Operating Frequency Version
A : 200kHz
B : 100kHz
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.
DS9241AB-05 March 2007
Features
z Two-Phase Power Conversion
z VRM 9.0 DAC Output with Active Droop
Compensation for Fast Load Transient
z Precise Channel Current Sharing with Differential
Sense Input
z Hiccup Mode Over Current Protection
z Programmable Under Voltage Lockout and Soft
Start
z High Ripple Frequency, (Channel Frequency Times
Channel Number)
z 100kHz Version (RT9241B) for Lower Switching Loss
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Power Supply for Server and Workstation
z Power Supply for High Current Microprocessor
Pin Configurations
(TOP VIEW)
VID4
VID3
VID2
VID1
VID0
COMP
FB
ADJ
DVD
SS
20
2
19
3
18
4
17
5
16
6
15
7
14
8
13
9
12
10
11
SOP-20
VDD
PGOOD
ISP1
PWM1
PWM2
ISP2
VSEN
GND
ISN1
ISN2
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