5

FN6901.0

April 27, 2009

Typical 12V Input DC/DC Application Schematic

RT

FB

COMP

SS/EN

REF

OSC

VIN

12V

C1

L1

C9

UGATE

OCSET

PHASE

BOOT

D1

Q1

C7

R2

R4

C11

R5

C10

C2

C6

C5

R1

C8

LGATE

Q2

2.5V/1.25V

R3

MONITOR AND

PROTECTION

+

-

GPIO1/REFIN <-- VREF = VDDQ/2

GPIO2

VMSET/MODE

CDEL

PGND

PVCC

SGND

VCC5

C4

C3

PGOOD

CONFIGURATION FOR DDR TERMINATION/EXTERNALLY REFERENCED TRACKING APPLICATIONS

VCC5

C12

REFOUT

1.25V VREF

VDDQ/VTT

TO REFIN OF VTT SUPPLY

+

-

ISL6420B