US3012/3012A

4-1

Rev. 1.0

5/6/98

TYPICAL APPLICATION

TYPICAL APPLICATION

DESCRIPTION

DESCRIPTION

The US3012 family of controller ICs are specifically de-

signed to meet Intel specification for Pentium II

™ and

Pentium Pro

™ microprocessor applications as well as

the next generation P6 family processors. These prod-

ucts feature a patented topology that in combination

with a few external components as shown in the typical

application circuit below ,will provide in excess of 16A

of output current for an on- board DC/DC converter while

automatically providing the right output voltage via the 5

bit internal DAC .These devices also feature, loss less

current sensing by using the Rds-on of the high side

Power MOSFET as the sensing resistor, a Power Good

window comparator that switches its open collector out-

put low when the output is outside of a

±10% window .

Other features of the device are ; Undervoltage lockout

for both 5V and 12V supplies as well as an external

programmable soft start function as well as program-

ming the oscillator frequency by using an external ca-

pacitor.

Dual Layout Compatible with RC5051

Designed to meet Intel specification of VRM8.2

& VRM8.3 for Pentium II

™

On board DAC programs the output voltage

from 1.3V to 3.5V (US3010) & 1.8V to 3.5V for

US3010A

Loss less Short Circuit Protection

Synchronous operation allows maximum

efficiency

Patented architecture allows fixed frequency

operation as well as 100% duty cycle during

dynamic load

Soft Start

High current totem pole driver for direct

driving of the external Power MOSFET

Power Good function

PACKAGE ORDER INFORMATION

PACKAGE ORDER INFORMATION

PRELIMINARY DATASHEET

FEATURES

FEATURES

5 BIT PROGRAMMABLE SYNCHRONOUS BUCK

CONTROLLER IC

APPLICATIONS

APPLICATIONS

Pentium II & Pentium Pro

™ processor DC to DC

converter application

Low cost Pentium with AGP

Notes: Pentium II and Pentium Pro are

trade marks of Intel Corp.

5V

12V

VID0

Power Good

3012app1-1.1

OutEn

Q2

VID1

VID2

VID3

VID4

L1

L2

C5

R2

C3

C4

C6

Q1

R3

R5

C7

R6

C11

C1

R7

C8

C2

R4

R9

R8

R12

R13

4

HDrv

LDrv

NC/Vccp

SS/Vref

CS+

Gnd

Vfb/

GndD

D3

D2

D4

D1

D0

US3012

En

PGd

CS-

V12

V5

18

12

19

5

20

9

15

10

11

14

1

3

2

16

7

13

8

6

17

NC/

GndA

NC/

GndP

Ct

R1

D1

R10

R11

C9

C10

Ta (

°C)

Device

Package

VID Voltage Range

0 TO 70

US3012CW

20 pin Plastic SOIC WB

1.3V to 3.5V

0 TO 70

US3012ACW

20 pin Plastic SOIC WB

1.8V to 3.5V