US3036

4-1

Rev. 1.1

12/4/98

8 PIN PWM SWITCHER

CONTROLLER IC

Typical application of US3036

TA (°C)

8 PIN PLASTIC

SOIC (S)

0 TO 70

US3036CS

DESCRIPTION

DESCRIPTION

The US3036 IC provides an 8 pin low cost switching

controller with true short circuit protection all in a

compact 8 pin surface mount package, providing a

low cost switching solution for applications that re-

quire a simple switching regulator from the 5V input where

there is no other supply available. One type of such

application is generating 2.5V standby from the dual

5V(5V and 5V standby) for the next generation proces-

sors. The IC starts below 4.5V supply and drives an

external Pch MOSFET or and external low cost PNP as

the switching element. 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

8 pin SOIC Switching Controller with

HICCUP Current Limiting Reduces Diode Power

Dissipation to Less than 1% of Normal Opera-

tion

Soft Start Capacitor allows for smooth Output

Voltage ramp up

On board MOSFET driver

Fastest transient response of any controller

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

1% internal voltage reference

Internal Under Voltage Lockout protects

MOSFET during start-up

APPLICATIONS

APPLICATIONS

Single input Switching Regulators such as Simple

5V to 2.5V switcher for RDRAM regulator

PACKAGE ORDER INFORMATION

PACKAGE ORDER INFORMATION

PRELIMINARY DATASHEET

TYPICAL APPLICATION

TYPICAL APPLICATION

3036app2-1.0

Vout

C1

L1

C3

Q2

C2

L2

R4

C7

D1

R2

C4

R5

R1

R3

C5

C8

US3036

R6

C6

R7

1

2 3

4

5

6

7

8

Drv Vcc

Vfb

NC

Gnd

CS-

CS+

SS

ATX

P.S.

5V

5V(S.B.)