Oct 3-06 Rev L

SP636 Synchronous Buck Controller

© 2006 Sipex Corporation

FEATURES

■ 5V to 24V Input step down converter

■ Up to 7A output in a small form factor

■ Highly integrated design, minimal components

■ Overcurrent circuit protection with auto-restart

■ Power Good Output, ENABLE Input

■ Maximum Controllable Duty Cycle Ratio up to 92%

■ Wide BW amp allows Type II or III compensation

■ Programmable Soft Start

■ Fast Transient Response

■ Available in Lead Free, RoHS Compliant

6-Pin QFN package

■ External Driver Enable/Disable

■ U.S. Patent #6,922,04

The SP636 is a synchronous step-down switching regulator controller optimized for high

efficiency. The part is designed to be especially attractive for single supply step down con-

version from 5V to 24V. The SP636 is designed to drive a pair of external NFETs using

a fixed 600 KHz frequency, PWM voltage mode architecture. Protection features include

UVLO, thermal shutdown, output short circuit protection, and overcurrent protection with

auto restart. The device also features a PWRGD output and an enable input. The SP636

is available in a space saving 6-pin QFN and offers excellent thermal performance.

TYPICAL APPLICATION CIRCUIT

DESCRIPTION

ISN

SP6136

16 Pin QFN

3mm x 3mm

8

7

6

5

4

3

2

1

GH

GL

PGND

V

FB

12

11

10

9

16

15

14

13

GND

ISP

SWN

RS3

10KΩ

CBST

0.1uF

R1

68.1kΩ, 1%

RZ3

1kΩ

R2

21.5kΩ, 1%

MT, Si4354DY

18.5 mΩ, 30V

CZ3

270pF

CP1

12 pF

RZ2

30.9kΩ

CZ2

560pF

MB, Si4886DY

13.5 mΩ, 30V

CF1

22pF

12V

CIN

22uF

CSP

6.8nF

VIN

GND

VOUT

GND

SS

VCC

POWERGOOD

CSS

47nF

ISP

ISN

EN

PGND

GND

PWRGD

VFB

COMP

VIN

BST

GH

SWN

UVIN

GL

3.3V

0-7A

DBST

SD101AWS

CVCC

4.7uF

C3

0.1uF

R5

10kΩ

SP6136

NC

CS

0.1uF

RS2

5.11KΩ

RS1

5.11KΩ

Inter-Technical SC7232-2R2

2.2uH, 13A, 10.4mΩ

COUT

100uF

ENABLE

Note: Die attach paddle is internally connected to GND.

SP6136

Synchronous Buck Controller