US2076

4-1

Rev. 1.3

4/26/98

PWM SWITCHER CONTROLLER & 7.5A

ADJUSTABLE LOW DROPOUT REGULATOR COMBO

TYPICAL APPLICATION

TYPICAL APPLICATION

Typical application of US2076 in a flexible motherboard designed for Intel

P55

™,P54™, AMD K5 & K6™ as well as Cyrix M1™ and M2™ applications.

Tj (°C)

7 PIN PLASTIC

7 PIN PLASTIC

TO220 (T)

TO263 (M)

0 TO 125

US2076CT

US2076CM

DESCRIPTION

DESCRIPTION

The US2076 is a dual function IC combining a

switching controller and a 7.5A adjustable low

dropout regulator all in a compact 7 pin TO220 and

TO263 surface mount packages providing a total so-

lution for dual supply processor applications such as

an Intel P55C

™, AMD K6™, as well as Cyrix 6X86L™

and the M2

™processors. Typically in these applications

a dual supply regulator converts 5V to 3.3V for I/O sup-

ply and a jumper programmable supply of 1.25V to 3.5V

for CORE supply.The linear regulator portion in the

US2076 is an adjustable one that can be programmed

to 3.30V output and has a minimum of 7.5A current ca-

pability designed to provide ample current for most ap-

plications. The US2076 uses an internal regulator gen-

erated from the 12V supply to power the switching con-

troller as well as the 12V supply to drive the power

MOSFET, allowing a low cost N channel MOSFET

switch to be used. The IC also includes an error com-

parator for fast transient response, a precise voltage ref-

erence for setting the output voltage as well as a direct

drive of the MOSFET for the minimum part count.

FEATURES

FEATURES

The US2076 eliminates the need for a

seperate switching controller IC

Minimum part count allows lower system cost

Adjustable 7.5A LDO on board

1.1V Dropout at 7.5A

On board MOSFET driver

Fastest transient response of any controller

method. ( 0 to 100% Duty Cycle in 100 nS )

1% internal voltage reference

Internal Thermal shutdown

Internal Under Voltage Lockout protects

MOSFET during start-up

APPLICATIONS

APPLICATIONS

Dual supply low voltage processor applications,

such as: P55C

™,CYRIX M2™, POWER PC™ and

AMD K6

™

PATENT PENDING

PRELIMINARY DATASHEET

Notes: P54C,P55C are trade marks of Intel Corp. K5 & K6 are trade marks of AMD corp. Cyrix 6X86L,M1,M2 are trade marks of Cyrix

Corp. Power PC is trade mark of IBM Corp.

PACKAGE ORDER INFORMATION

PACKAGE ORDER INFORMATION

2076app1-1.2

12V

5V

C1

L1

R1

Q2

D1

C3

C2

C7

L2

C6

R4

R7

R6

D2

CPU

I / O

Vcc2 Det

Core

R8

5V

R5

US2076

Drv

V12

Vfb1

Gnd

Vfb2

Vout

Vin

1

2

3

4

5

6

7