Rainbow-electronics MAX1813 Manual de usuario descargar pdf

General Description

The MAX1813 step-down controller is intended for core

CPU DC-DC converters in notebook computers. The

controller features a dynamically adjustable output (5-

bit DAC), ultra-fast transient response, high DC accura-

cy, and high efficiency necessary for leading-edge

CPU core power supplies. Maxim’s proprietary Quick-

PWM™ quick-response, constant-on-time PWM control

scheme handles wide input/output voltage ratios with

ease and provides 100ns “instant-on” response to load

transients while maintaining a relatively constant switch-

ing frequency.

The MAX1813 is designed specifically for CPU core

applications requiring a voltage-positioned supply. The

voltage-positioning input (VPCS), combined with a

high-DC-accuracy control loop, is used to implement a

power supply that modifies its output set point in

response to the load current. This arrangement

decreases full-load power dissipation and reduces the

required number of output capacitors.

The output voltage can be dynamically adjusted

through the 5-bit digital-to-analog converter (DAC)

inputs over a 0.600V to 2V range. The MAX1813

includes an internal multiplexer that selects between

three different DAC code settings. The first two inputs

are controlled by five digital input pins (D0–D4). The

third input is used for the suspend mode and controlled

by two 4-level input pins (S0, S1). Output voltage transi-

tions are accomplished with a proprietary precision

slew-rate control that minimizes surge currents to and

from the battery while guaranteeing “just-in-time” arrival

at the new DAC setting.

The MAX1813’s 28V input range enables single-stage

buck conversion from high-voltage batteries for the

maximum possible efficiency. Alternatively, the con-

troller’s high-frequency capability combined with two-

stage conversion (stepping down the +5V system

supply instead of the battery) allows the smallest possi-

ble physical size.

The MAX1813 is available in a 28-pin QSOP package.

Applications

Notebook Computers

(Intel IMVP–II

™

/Coppermine™)

Docking Stations

CPU Core Supply

Single-Stage (BATT to V

CORE

) Converters

Two-Stage (+5V to V

CORE

) Converters

Features

♦ High-Efficiency Voltage Positioning

♦ Quick-PWM Architecture

♦ ±1% V

OUT

Accuracy Over Line

♦ Adjustable Output Slew Rate

♦ 0.600V to 2V Adjustable Output Range (5-Bit DAC)

♦ 2V to 28V Battery Input Range

♦ 200/300/600/1000kHz Switching Frequency

♦ Output Undervoltage and Overvoltage Protection

♦ Drives Large Synchronous-Rectifier MOSFETs

♦ ±20% Accurate Current-Limit

♦ 10µA Shutdown Supply Current

♦ 2V ±1% Reference Output

♦ Power-Good (PGOOD) Indicator

♦ Small 28-Pin QSOP Package

MAX1813

Dynamically-Adjustable, Synchronous Step-Down

Controller with Integrated Voltage Positioning

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-2010; Rev 0; 4/01

For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

PART TEMP. RANGE PIN-PACKAGE

MAX1813EEI -40°C to +85°C 28 QSOP

Quick-PWM is a trademark of Maxim Integrated Products, Inc.

Coppermine and IMVP-

ΙΙ

are trademarks of Intel Corp.

Typical Operating Circuit appears at end of data sheet.

BST

PGND

CODE

ZMODE

SUS

GND

PGOOD

ILIM

REF

TON

TIME

SKP/SDN

VPCS

V+

QSOP

TOP VIEW

MAX1813

Pin Configuration

1 2 3 4 5 6 ... 37 38

Indice de contenidos

Pagina 1 - Pin Configuration

General DescriptionThe MAX1813 step-down controller is intended for coreCPU DC-DC converters in notebook computers. Thecontroller features a dynamical

Pagina 2 - ELECTRICAL CHARACTERISTICS

MAX1813Dynamically-Adjustable, Synchronous Step-DownController with Integrated Voltage Positioning10 _________________________________________________

Pagina 3