POWER MANAGEMENT

1

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SC2688

Programmable Synchronous DC/DC

Converter, Dual LDO Controller

Features

Applications

Revision: March 25, 2004

Description

The SC2688 combines a synchronous voltage mode

controller with two low-dropout linear regulators

providing most of the circuitry necessary to implement three

DC/DC converters for powering advanced microprocessors

The SC2688 switching section features latched drive out-

put for enhanced noise immunity, pulse by pulse current

limiting and logic compatible shutdown. The SC2688

switching section operates at a fixed frequency of 140kHz,

providing an optimum compromise between size, efficiency

and cost in the intended application areas.

The SC2688 linear sections are low dropout regulators

with short circuit protection, supplying 1.5V for GTL bus

and 2.5V for non-GTL I/O.

·Synchronous design, enables no heatsink solution

95% efficiency (switching section)

1.5V, 2.5V short circuit protected linear controllers

Typical Application Circuit

0.1uF

EN

2R2

1.5V

1k

1.9uH

+

330uF

2R2

3.3V

2.5V

0.1uF

SC2688S

16

4

5

6

7

8

11

12

13

10

9

15

1

14

2

3

AGND

VCC

LDOEN

CS-

CS+

DH

BST

EN

FB

DL

PGND

GATE2

GATE1

LDOV

LDOS1

LDOS2

x6

12V

0.1uF

1.00k

0.1uF

+

330uF

VCC_CORE

5mOhm

0.1uF

x4

+

330uF

+

1500uF

10

+

1500uF

5V

2.32k

+

47uF