RICHTEK RT9221CS Datasheet

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

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

Power Supply for Pentium, Pentium ProTM,

z

Pentium II

Alpha

High-power 5V to 3.xV DC-DC Regulators

z

Low-voltage Distributed Power Supplies

z

Programmable Power Supplies

z

TM

TM

, Power PCTM, K6TM, 6×86TM, and

Microprocessors

RT9221 

Package type
S : SOP-24

Operating temperature range

C: Commercial standard

Pin Configurations

Part Number Pin Configurations

RT9221CS

(Plastic SOP-24)

GND
GATE1
LDOS1

LDOS2

VCC

OVP

PGOOD

CSN

CSP

PGNDH

DH BSTL

PGNDL

TOP VIEW

1

2

3

4

5

6

7

8

9

10

11

12 13

24

23

22

21

20

19

18

17

16

15

14

GATE2
LDOV

VID0

VID1

VID2

VID3

VID4

VSEN

SHDN
BSTH

DL

DS9222-05 May 2001 www.richtek-ic.com.tw

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RT9221

Absolute Maximum Ratings

z VCC to GND -0.3 to +5.5V

z PGND to GND ± 0.3V

z BSTH and BSTL to GND -0.3 to +14V

z Ambient Temperature Range 0 to +70°C

z Junction Temperature Range 0 to +125°C

z Storage Temperature Range -65 to +150°C

z Lead Temperature (Soldering, 10 sec.) 300°C

z Package Thermal Resistance

SOP-24, θ

JA

Electrical Characteristics

75°C/W

(VCC = 5V; GND = 0V; PGNDH = PGNDL = 0V; VSEN = VOUT; 0mV < (V

CSP-VCSN

) < 60mV; T

= 25°C)

A

Parameter Symbol Test Conditions Min Typ Max Units

Switching Section

Output Voltage

Supply Voltage

Supply Current

Load Regulation

Line Regulation

V

OUT

V

CC

I

CC

∆V

LOADIO

∆V

LINE

IO = 2A

VCC 4.5 -- 5.5 V

= 0.8A to 15A

VCC = 4.75V to 5.25V -- 0.5 -- %

-- (1) -- --

-- 3 6 mA

-- 1 -- %

Power On Reset Trip Point VCC Rising -- 4.2 --

Current Limit Voltage

V

LIMIT

V

CSP

- V

CSN

65 75 85

Oscillator Frequency 170 200 230

Oscillator Max Duty Cycle

DH Source

DH Sink

DL Source

DL Sink

D

MAX

V

V

V

V

BSTH

- V

DH

BSTH

- V

DL

- V

DH

PGNDH

- V

DL

PGNDL

= 1V

= 1V

= 3V

= 1V

90 95 --

-- 3.5 --

-- 3.5 --

-- 2 --

-- 2 --

OVP Threshold Voltage 114 120 122

V

mV

KHz

%

Ω

Ω

Ω

Ω

%

OVP Source Current

I

OVP

V

OVP

= 3.0V

Power Good Threshold Voltage VSEN Rising 87 -- 113

10 -- --

mA

%

Linear Sections

Quiescent Current

I

Q

Output Voltage (LDO1 RT9221) 2.450 2.500 2.550

Output Voltage (LDO2 RT9221) 1.470 1.500 1.530

Gain (AOL)

Load Regulation

Line Regulation

∆V

LOADIO

∆V

LINE

LDOV = 12V ----5

LDOS (1,2) to GATE (1,2) -- 65 --

= 0 to 5A

-- 1 --

LDOV = 11.4V to 12.6V -- 1 --

mA

V

V

dB

%

%

Note: (1) See output voltage table.

www.richtek-ic.com.tw DS9222-05 May 2001

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Function Block Diagram

1. 25 V REF

VID4

VID3

VID2

VID1

VID0

DAC

VCC

CSN

CSP

+

_

70mV

OSCILLATOR

CURRENT LIMI T

R

Q

S

SHDN

LEVEL SHIFT
AND DRI VER

RT9221

BSTH

DH

PGNDH

VSEN

PGOOD

OVP

LDOS 1

GATE1

OPEN
DRAIN

_

_

VCC

LINEAR

CONTROLLER

2. 5V

SHOOT-

200KHz

REF

_

+

CONTROLLER

LINEAR

1. 5V

+

+

+

_

+

_

ERRO R AM P

GND

1. 26 5V

LDOV

THROUGH
CONTROL

DRIVER

LDOS 2GATE2

BSTL

DL

PGNDL

GND

DS9222-05 May 2001 www.richtek-ic.com.tw

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RT9221

Pin Description

Pin No. Pin Name Pin Function

1 GND Small signal analog and digital ground

2 GATE1 LDO1 gate drive output

3 LDOS1 LDO1 sense input

4 LDOS2 LDO2 sense input

5 VCC Input voltage

6OVP

7

PGOOD

High signal out if V

(1)

Open collector logic output; High if V0 within 10% of the setting point

> setting point + 20%

0

8 CSN Current sense input (Negative)

9 CSP Current sense input (Positive)

10 PGNDH High side drive GND

11 DH High side drive output

12 PGNDL Low side drive GND

13 DL Low side drive output

14 BSTL Supply for low side driver

15 BSTH Supply for high side driver

16

SHDN

(1)

Logic low shutdown the converter

17 VSEN Top end of internal feedback chain

18

19

20

21

22

VID4

VID3

VID2

VID1

VID0

(1)

(1)

(1)

(1)

(1)

Programming input (MSB)

Programming input

Programming input

Programming input

Programming input (LSB)

23 LDOV +12V for LDO section

24 GATE2 LDO2 gate drive output

Note: (1) All logic level inputs and outputs are TTL compatible.

www.richtek-ic.com.tw DS9222-05 May 2001

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Table 1 Output Voltage Program

RT9221

Test Conditions

Output Voltage IO = 2A in application circuit

VID

43210

01111 1.287 1.300 1.313

01110 1.336 1.350 1.364

01101 1.386 1.400 1.414

01100 1.435 1.450 1.465

01011 1.485 1.500 1.515

01010 1.534 1.550 1.566

01001 1.584 1.600 1.616

01000 1.633 1.650 1.667

00111 1.683 1.700 1.717

00110 1.732 1.750 1.768

00101 1.782 1.800 1.818

00100 1.831 1.850 1.869

00011 1.881 1.900 1.919

00010 1.930 1.950 1.970

00001 1.980 2.000 2.020

Min Typ Max Units

V

00000 2.029 2.050 2.071

11111 1.980 2.000 2.020

11110 2.079 2.100 2.121

11101 2.178 2.200 2.222

11100 2.277 2.300 2.323

11011 2.376 2.400 2.424

11010 2.475 2.500 2.525

11001 2.574 2.600 2.626

11000 2.673 2.700 2.727

10111 2.772 2.800 2.828

10110 2.871 2.900 2.929

10101 2.970 3.000 3.030

10100 3.069 3.100 3.131

10011 3.168 3.200 3.232

10010 3.267 3.300 3.333

10001 3.366 3.400 3.434

10000 3.465 3.500 3.535

DS9222-05 May 2001 www.richtek-ic.com.tw

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RT9221

Typical Application Circuit

12V

5V

+

C10

C2

0.1µF

R9

5

Ω

R1

10KR210

C4

5
6

OVP

22

VID0

21

VID1

20

VID2

19

VID3

16

SHDN

1

GND

PGNDL

24

GATE2

2

GATE1

43

LDOS2

RFD3055

VID0

VID1

VID2

VID3

VID4

OVP

SHDN

PGOOD

1000µF

5V

5V

C9

C1

0.1µF

1500µFx2

++

1000µF

R14

10

VCC

R13

10

RT9221

Q4

C14
1µF

CSP

CSN

VSEN

PGOOD

VID4

BSTH

DH

PGNDH

DL

BSTL

LDOV

LDOS1

C11

0.1µF

17

7
18

15

11

10

1312

14
23

C13
1µF

R3

10K

9

8

R8
5

Ω

+

0.1µF

PHB83N03LT
Q1

Q2
PHB95N03LT

C12
1000µF

C3

L1

4µH

R4

1.0K

R6

5m

RFD3055

Q3

C8

0.1µF

R5

2.32K

Ω

+

C5 C6

1500µFx4

0.1µF

+

C7

1000µF

VCC_ CORE

GND

VLIN1

VLIN2

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Package Information

RT9221

H

M

B

A

C

FD

Dimensions In Millimeters Dimensions In Inches

Symbol

Min Max Min Max

A 15.189 15.596 0.598 0.614

B 7.391 7.595 0.291 0.299

C 2.362 2.642 0.093 0.104

D 0.330 0.508 0.013 0.020

I

B

J

F 1.194 1.346 0.047 0.053

H 0.229 0.330 0.009 0.013

I 0.102 0.305 0.004 0.012

J 10.008 10.643 0.394 0.419

M 0.381 1.270

DS9222-05 May 2001 www.richtek-ic.com.tw

0.015 0.050

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RT9221

RICHTEK TECHNOLOGY CORP.

Headquarter

6F, No. 35, Hsintai Road, Chupei City

Hsinchu, Taiwan, R.O.C.

Tel: [phone] Fax: [phone]

www.richtek-ic.com.tw DS9222-05 May 2001

RICHTEK TECHNOLOGY CORP.

Taipei Office (Marketing)

8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City

Taipei County, Taiwan, R.O.C.

Tel: [phone] Fax: [phone]

Email: [e-mail]

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