5

Mar -07 Rev AJ

SP7662 Wide Input Voltage Range 2A, 300kHz Buck Regulator

© 2007 Sipex Corporation

PIN DESCRIPTION

Pin #

Pin

Name

Description

-4

PGND Groundconnectionforthesynchronousrectifier.

5, 9,

GroundPin.ThecontrolcircuitryoftheICandlowerpowerdriverarereferencedtothis

6

VFB

Feedback Voltage and Short Circuit Detection pin. It is the inverting input of the

Error Amplifier and serves as the output voltage feedback point for the Buck

Converter. The output voltage is sensed and can be adjusted through an external

resistor divider. Whenever VFB drops 0.25V below the positive reference, a short

circuit fault is detected and the IC enters hiccup mode.

7

COMP

OutputoftheErrorAmplifier.Itisinternallyconnectedtotheinvertinginputofthe

PWMcomparator.Anoptimalfiltercombinationischosenandconnectedtothis

pin and either ground or VFB to stabilize the voltage mode loop.

8

SS

SoftStart.ConnectanexternalcapacitorbetweenSSandGNDtosetthesoftstart

rate based on the 0µA source current. The SS pin is held low via a mA (min)

current during all fault conditions.

0

ISN

Current sense negative input. Rail-to-rail input for overcurrent detection.



ISP

Current sense positive input. Rail-to-rail input for overcurrent detection.

2

SWN LowersupplyrailfortheGHhigh-sidegatedriver.Connectthispintotheswitching

node as close as possible to pins 23- 27. Do not connect this pin to pins 4 – 6.

3

VINP Input connection to the high side N-channel MOSFET.

4-6,

23-26

LX

7

BST

High side driver supply pin. Connect BST to the external boost diode and capacitor

as shown in the Typical Application Circuit on page . The high side driver is

connected between BST pin and SWN pin.

8

VIN

2

UVIN

tosetminimumoperatingvoltage.Useresistorvaluesbelow20kΩtooverride

internal resistor divider.

22

VCC Output of internal regulator. May be exterinally biased if Vin < 5V.

SP7662

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

BOTTOM VIEW

Heatsink Pad 1

Connect to Lx

Heatsink Pad 2

Connect to GND

Heatsink Pad 3

GND

COMP

SWN

LX

LX

LX

LX

BST

LX

LX

LX

DFN PACKAGE

7mm x 4mm (Option 2)

VINP

SS

ISN

ISP

GND

GND

GND

Pin 27

Pin 28

Pin 29