Rainbow-electronics MAX15041 Manual de usuario descargar pdf (Pagina 1)

General Description

The MAX15041 low-cost, synchronous DC-DC convert-

er with internal switches delivers an output current up to

3A. The MAX15041 operates from an input voltage of

4.5V to 28V and provides an adjustable output voltage

from 0.6V to 90% of V

, set with two external resistors.

The MAX15041 is ideal for distributed power systems,

preregulation, set-top boxes, television, and other con-

sumer applications.

The MAX15041 features a peak-current-mode PWM con-

troller with internally fixed 350kHz switching frequency

and a 90% maximum duty cycle. The current-mode con-

trol architecture simplifies compensation design, and

ensures a cycle-by-cycle current limit and fast response

to line and load transients. A high-gain transconductance

error amplifier allows flexibility in setting the external com-

pensation by using a type III compensation scheme,

thereby allowing the use of all ceramic capacitors.

This synchronous buck regulator features internal

MOSFETs that provide better efficiency than asynchro-

nous solutions, while simplifying the design relative to

discrete controller solutions. In addition to simplifying

the design, the integrated MOSFETs minimize EMI,

reduce board space, and provide higher reliability by

minimizing the number of external components.

The MAX15041 also features thermal shutdown and

overcurrent protection (high-side sourcing and low-side

sinking), and an internal 5V LDO with undervoltage

lockout. In addition, this device ensures safe startup

when powering into a prebiased output.

Other features include an externally adjustable soft-start

that gradually ramps up the output voltage and reduces

inrush current. Independent enable control and power-

good signals allow for flexible power sequencing.

The MAX15041 is available in a space-saving, high-

power, 3mm x 3mm, 16-pin TQFN-EP package and is

fully specified from -40°C to +85°C.

Applications

Distributed Power Systems

Wall Adapters

Preregulators

Set-Top Boxes

Televisions

xDSL Modems

Consumer Products

Features

o Up to 3A of Continuous Output Current

o ±1% Output Accuracy Over Temperature

o 4.5V to 28V Input Voltage Range

o Adjustable Output Voltage Range from 0.606V to

0.9 x V

o Internal 170mΩ R

DS-ON

High-Side and 105mΩ

DS-ON

Low-Side Power Switches

o Fixed 350kHz Switching Frequency

o Up to 93% Efficiency

o Cycle-By-Cycle Overcurrent Protection

o Programmable Soft-Start

o Stable with Low-ESR Ceramic Output Capacitors

o Safe Startup into Prebiased Output

o Enable Input and Power-Good Output

o Fully Protected Against Overcurrent and

Overtemperature

o V

LDO Undervoltage Lockout

o Space-Saving, Thermally Enhanced, 3mm x 3mm

Package

MAX15041

Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM

Step-Down DC-DC Regulator with Internal Switches

________________________________________________________________

Maxim Integrated Products

MAX15041

INPUT

12V

BST

OUTPUT

1.8V AT 3A

PGND

COMP

PGOOD

SGND

Typical Operating Circuit

Ordering Information

19-4815; Rev 0; 7/09

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

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

EVALUATION KIT

AVAILABLE

PART

TEMP RANGE

PIN-

PACKAGE

TOP

MARK

MAX15041ETE+

-40°C to +85°C 16 TQFN-EP*

AGV

Denotes a lead(Pb)-free/RoHS-compliant package.

EP = Exposed pad.

Pin Configuration appears at end of data sheet.

1 2 3 4 5 6 ... 15 16

MAX15041 1

Indice de contenidos

Pagina 1 - MAX15041

General DescriptionThe MAX15041 low-cost, synchronous DC-DC convert-er with internal switches delivers an output current up to3A. The MAX15041 operate

Pagina 2

MAX15041Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches10 ______________________________________________

Pagina 3

Inductor SelectionA larger inductor value results in reduced inductor ripplecurrent, leading to a reduced output ripple voltage.However, a larger indu

Pagina 4

MAX15041Having defined the power modulator’s transfer functiongain, the total system loop gain can be written as fol-lows (see Figure 1):where ROUTis

Pagina 5