RT9226B Datasheet, PDF (1/6 Pages) List of Unclassifed Manufacturers – SYNCHRONOUS PWM STEP-DOWN DC/DC CONVERTER CONTROLLER

Preliminary
RT9226B
Synchronous PWM Step-down DC/DC Converter Controller
General Description
The RT9226B is a low cost, high-efficiency voltage-
mode PWM controller for motherboard power supply
application. Synchronous N-channel MOSFET driver,
short-circuit protection, and soft start function are
integrated in a single chip. A simple high power buck
regulator with shutdown function can be
implemented with minimum external components.
The RT9226B provides current-limit protection by
monitoring the voltage drop across N-channel
MOSFET in over current condition, therefore,
eliminates the current sensing resistor and minimizes
the efficiency loss. The soft start function reduces the
stress on power supply and components in power on
duration. The 200 kHz operating frequency and high
speed PWM control loop with Synchronous N-
channel MOSFET driver provide optimized
compromise between efficiency, cost, and response
speed. Other features include output voltage
monitoring for power good indication and over
voltage protection.
Ordering Information
RT9226B… …
Package type
S : SOP-14
Operating temperature range
C: Commercial standard
Features
z Synchronous N-channel MOSFET Driver
z High Efficiency
z Fast Response with 200kHz Operating
Frequency
z Adjustable Current Limit by Sensing MOSFET
R_DS(ON), without Extra Current Sensing
Resistor
z Shutdown Function
z Power Good Indication Output and Over-
voltage Protection
Applications
z Low Cost CPU Power Supply
z Motherboard I/O Power Supply
z Add-On Card Power Supply
z DDR SDRAM Bus Terminator Power Supply
Pin Configurations
Part Number
RT9226BCS
(Plastic SOP-14)
Pin Configurations
TOP VIEW
VSEN ₁
OCSET ₂
SS ₃
FB ₄
EN ₅
GND ₆
PGNDH 7
14 VCC
13 LGATE
12 PGNDL
11 BOOT
10 UGATE
9 PHASE
8 PGOOD
DS9226B-01 May 2001
www.richtek-ic.com.tw
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