RT9232B
Programmable Frequency Synchronous Buck PWM Controller
General Description
The
RT9232B
is a single-phase synchronous buck PWM
DC-DC converter controller designed to drive two
N- MOSFETs. It provides a highly accurate, programmable
output voltage precisely regulated to low voltage
requirement with an internal 0.8V
±
1% reference.
The
RT9232B
uses an external compensated, single
feedback loop voltage mode PWM control for fast transient
response. An oscillator with Programmable frequency
(50kHz to 800kHz) reduces the external inductor and
capacitor component size for saving PCB board area.
The RT9232B
provides fast transient response to satisfy
high current output applications (up to 25A) while
minimizing external components. It is suitable for high-
performance graphic processors, DDR and VTT power.
The RT9232B integrates complete protect functions such
as Soft Start, Output Enable, UVLO(under-voltage lockout)
and OCP into a small 14-pin
package.
Features
Single IC Supply Voltage : 12V
Single phase DC/DC Buck Converter with
High Output Current (up to 25A )
Low Output Voltage (down to 0.8V )
High Input Voltage (up to 12V )
Operate from 12V, 5V or 3.3V Input
0.8V
±
1% Internal Reference
Adaptive Non-Overlapping Gate Drivers
Integrated High-Current, HV Gate Drivers
External Programmable Soft Start
External Programmable Frequency
(Range : 50kHz to 800kHz, 200kHz Free Run )
Provide Over Current Protection by Sensing
MOSFET R
DS(ON)
On/Off Control by Enable Pin
Drives Two N-MOSFET
Full 0 to 100% Duty Cycle
Fast Transient Response
Voltage Mode PWM Control with External
Feedback Loop Compensation
RoHS Compliant and 100% Lead (Pb)-Free
Applications
System (Graphic, MB) with 12V Power.
Graphic Cards (AGP 8X, 4X, PCI Express*16) :
High-Current for High-Performance Graphic Processors
(GPU, VPU)
Middle Current for High-Performance Graphic Memory
Power (DDR, DDR II)
Low Current with Sink Capacity for High-Performance
Graphic Memory Power (DDR/VTT)
3.3V to 12V Input DC-DC Regulators
Low Voltage Distributed Power Supplies
Ordering Information
RT9232B
Package Type
S : SOP-14
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Note :
Pin Configurations
(TOP VIEW)
RT
OCSET
SS
COMP
FB
EN
GND
2
3
4
5
6
7
14
13
12
11
10
9
8
VCC
PVCC
LGATE
PGND
BOOT
UGATE
PHASE
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.
SOP-14
DS9232B-03 March 2007
www.richtek.com
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