RT9221 Datasheet, PDF (1/8 Pages) List of Unclassifed Manufacturers – PROGRAMMABLE SYNCHRONOUS PWM BUCK CONVERTER WITH 1.5V / 2.5V DUAL LOW DROPOUT LINEAR REGULATOR CONTROLLER

RT9221
Programmable Synchronous PWM Buck Converter with
1.5V/2.5V Dual Low Dropout Linear Regulator Controller
General Description
The RT9221 integrates a PWM controller and two
low-dropout linear regulators into a single chip. The
PWM controller provides the CPU core voltage
controlled by a 5-bit DAC and the linear section
regulates power for GTL bus, clock driver or other
circuits on motherboards. The PWM controller
provides an adjustable Intel-compatible 1.3V~3.5V
output voltage. The synchronous N-MOSFET driver
with 200 KHz switching frequency optimizes the
efficiency, device size, and cost built-in over–voltage
and current-limiting protection prevent the CPU from
damage. Power-good signal is sent when the core
voltage is within ±10% of the setting point.
The linear section is a low dropout regulator which
drives low cost NPN transistors to supply the 1.5V
and 2.5V regulated output power.
Ordering Information
RT9221… …
Package type
S : SOP-24
Operating temperature range
C: Commercial standard
Features
z Provides 3 Regulated Voltages
z N-MOSFET Driver for High Efficiency
Switching Section
z Power-good, Over-voltage, and Current-
limiting Protection for Switching Section
z 1.5V and 2.5V Fixed Output Voltage for Linear
Section
z Linear Section Uses Low Cost NPN Transistor
as Power Device
z TTL-compatible 5-bit DAC Core Output
Voltage
Applications
z Power Supply for Pentium, Pentium Pro^TM,
Pentium II^TM, Power PC^TM, K6^TM, 6×86^TM, and
Alpha^TM Microprocessors
z High-power 5V to 3.xV DC-DC Regulators
z Low-voltage Distributed Power Supplies
z Programmable Power Supplies
Pin Configurations
Part Number
Pin Configurations
TOP VIEW
RT9221CS
GND 1
(Plastic SOP-24) GATE1 2
LDOS1 3
LDOS2 4
VCC 5
OVP 6
PGOOD 7
CSN 8
CSP 9
PGNDH 10
DH 11
PGNDL 12
24 GATE2
23 LDOV
22 VID0
21 VID1
20 VID2
19 VID3
18 VID4
17 VSEN
16 SHDN
15 BSTH
14 BSTL
13 DL
DS9222-05 May 2001
www.richtek-ic.com.tw
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