1

Date: 03/25/05

SP7653 Wide Input Voltage Range, 1.3MHz, Buck Regulator

© Copyright 2005 Sipex Corporation

SP7653

FEATURES

■ 2.5V to 20V Step Down Achieved Using Dual Input

■ Output Voltage down to 0.8V

■ 3A Output Capability

■ Highly Integrated Design, Minimal Components

■ 1.3MHz Fixed Frequency Operation

■ Over Temperature Protection

■ Short Circuit Protection with Auto-Restart

■ Wide BW Amp Allows Type II or III Compensation

■ Programmable Soft Start

■ Fast Transient Response

■ High Efficiency: Greater than 95% Possible

■ Asynchronous Start-Up into a Pre-Charged Output

■ Small 7mm x 4mm DFN Package

Wide Input Voltage Range, 1.3MHz,

Buck Regulator

The SP7653 is a synchronous step-down switching regulator optimized for high efficiency. The part is designed to be

especially attractive for dual supply, 12V to 20V distributed power systems stepped down with 5V used to power the

is designed to provide a fully integrated buck regulator solution using a fixed 1.3MHz frequency, PWM voltage mode

architecture. Protection features include Under Voltage Lock Out (UVLO), thermal shutdown and output short circuit

protection. The SP7653 is available in the space saving DFN package

.

®

Preliminary

TYPICAL APPLICATION CIRCUIT

Now Available in Lead Free Packaging

DESCRIPTION

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

TOP VIEW

Heatsink Pad 1

Connect to Lx

Heatsink pad 2

Connect to GND

Heatsink pad 3

Connect to V

IN

GND

COMP

UVIN

GND

SS

LX

LX

LX

LX

GND

GND

GND

BST

NC

LX

LX

LX

DFN PACKAGE

7mm x 4mm

SP7653

Blox

TM

C BST

1uF

R3

200k,1%

L1: IHLP2525CZER2R2M01

2.2uH, Irate =8A

U 2

SPX5205

VIN

1

GND

2

EN

3

BYP

4

VOUT

5

C1

22uF

C VCC

2.2uF

U1

SP7653

P GND

1

P GND

2

P GND

3

GND

4

V FB

5

COMP

6

UVIN

7

GND

8

S S

9

V IN

10

V IN

11

V IN

12

V IN

13

LX

14

LX

15

LX

16

NC

17

BST

18

GND

19

GND

20

GND

21

VCC

22

LX

23

LX

24

LX

25

LX

26

D BST

CSS

22nF

C P1

3.3pF

3.30V

0-3A

16V

R 2

21.5k,1%

GND

C 3

47uF

C3

CERAMIC

X5R

C 5

22uF

Notes:

6.3 V

12V

DCR=18mOhm

VIN

SD101AWS

U1 Bottom-Side Layout should have three

Contacts which are isolated from one

another:

QT Contact, QB Drain Contact, and

Controller GND Contact.

ALL RESISTORS & CAPACITORS SIZE 0603 UNLESS

OTHERWISE SPECIFIED.

RZ3

158,1%

VOUT

GND2

R4

100k,1%

C 2

0.1uF

C1,C5

CERAMIC

X5R

16V

CZ3

820p F

CZ2

1.5nF

R 1

68.1k,1%

RZ2

38.3k, 1%

CF1

100pF

fs=1.3MHz

R BST

5.11, 1%