RT9244

1

DS9244-06 March 2007

www.richtek.com

Multi-Phase PWM Controller for CPU Core Power Supply

Ordering Information

General Description

The RT9244 is a multi-phase buck DC/DC controller

integrated with all control functions for GHz CPU VRM.

The RT9244 controls 2, 3 or 4 buck switching stages

operating in interleaved phase set automatically. The multi-

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.

RT9244 controls both voltage and current loops to achieve

good regulation, response & power stage thermal balance.

builds precise load line for strict VRM DC & transient

specification and also ensures thermal balance of different

power stages. The settings of current sense, droop tuning,

independent to compensation circuit of voltage loop. The

feature greatly facilitates the flexibility of CPU power supply

design and tuning.

The DAC output of RT9244 supports K8 CPU by 5-bit VID

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.

Features

Multi-Phase Power Conversion with Automatic

Phase Selection

K8 DAC Output with Active Droop Compens-ation

for Fast Load Transient

Sense

Hiccup Mode Over-Current Protection

Programmable Switching Frequency (50kHz to

400kHz per Phase), Under-Voltage Lockout and

Soft-Start

High Ripple Frequency Times Channel Number

RoHS Compliant and 100% Lead (Pb)-Free

Applications

Regulator

Low Output Voltage, High Current DC-DC Converters

Voltage Regulator Modules

Pin Configurations

(TOP VIEW)

SOP-32

6

7

8

21

22

23

9

10

11

18

19

20

12

13

14

16

15

17

4

5

24

25

26

2

3

27

28

29

30

31

32

SS

OVP

VID3

VID2

ISP4

PWM4

PGOOD

DVD

VID1

VID0

PWM1

ISP1

RT

PWM2

COMP

FB

ISP2

GND

ADJ

VDIF

PWM3

ISP3

VSEN

SGND

SS2

VCC

ISN4

VID4

ISN3

ISN1

ISN2

VOSS

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.

RT9244

Package Type

S : SOP-32

Operating Temperature Range

P : Pb Free with Commercial Standard

G : Green (Halogen Free with Commer-

cial Standard)