Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - DC/DC voltage regulator Holder TQFN 16 EP

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 II 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 3; 3/11

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.

Summary of content (18 pages)

PAGE 1
9-4815; Rev 3; 3/11 KIT ATION EVALU E L B A IL AVA Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches The MAX15041 low-cost, synchronous DC-DC converter 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 VIN, set with two external resistors.
PAGE 2
MAX15041 Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches ABSOLUTE MAXIMUM RATINGS IN to SGND.............................................................-0.3V to +30V EN to SGND .................................................-0.3V to (VIN + 0.3V) LX to PGND ................................-0.3V to min (+30V, VIN + 0.3V) LX to PGND .....................-1V to min (+30V, VIN + 0.3V) for 50ns PGOOD to SGND .....................................................-0.
PAGE 3
Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches (VIN = 12V, CVDD = 1µF, CIN = 22µF, TA = TJ = -40°C to +85°C, typical values are at TA = +25°C, unless otherwise noted.) (Note 3) PARAMETER SYMBOL CONDITIONS MIN +100 VFB = 0.7V -100 +100 IFB SS Current ISS VSS = 0.45V, sourcing SS Discharge Resistance RSS ISS = 10mA, sinking, VEN = 1.6V 4.
PAGE 4
Typical Operating Characteristics (VIN = 12V, VOUT = 3.3V, CVDD = 1µF, CIN = 22µF, TA = +25°C, circuit of Figure 3 (see Table 1 for values), unless otherwise specified.) EFFICIENCY vs. LOAD CURRENT VOUT = 5.0V 75 VOUT = 3.3V 70 VOUT = 2.5V 65 VOUT = 1.8V VOUT = 1.2V 60 55 50 85 80 75 VOUT = 3.3V 70 65 VOUT = 2.5V 60 VOUT = 1.8V 55 VOUT = 1.2V 50 0.5 1.0 1.5 2.0 3.0 2.5 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 0 0.5 1.0 1.5 2.0 3.0 2.5 0 0.5 1.0 1.5 2.
PAGE 5
Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches INPUT SUPPLY CURRENT vs. INPUT VOLTAGE 13 12 8 7 6 5 4 3 2 11 4.0 MAX15041 toc11 9 SHUTDOWN CURRENT (FA) 14 10 MAX15041 toc10 L = 4.7FH ILOAD = 0A SHUTDOWN CURRENT (FA) MAX15041 toc09 INPUT SUPPLY CURRENT (mA) 16 15 SHUTDOWN CURRENT vs. TEMPERATURE SHUTDOWN CURRENT vs. INPUT VOLTAGE 3.5 3.0 2.5 2.0 1.5 1 1.
PAGE 6
Typical Operating Characteristics (continued) (VIN = 12V, VOUT = 3.3V, CVDD = 1µF, CIN = 22µF, TA = +25°C, circuit of Figure 3 (see Table 1 for values), unless otherwise specified.) SOFT-START TIME vs. CAPACITANCE STARTUP INTO PREBIASED OUTPUT MAX15041 toc17 MAX15041 toc16 1000 SOFT-START TIME (ms) VEN 5V/div 100 VOUT 2V/div 10 IL 2A/div 1 IOUT 2A/div 0.1 1 10 100 400µs/div 1000 CSS (nF) MAX15041 toc18 3.
PAGE 7
Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches MAXIMUM LOAD CURRENT (A) VIN = 12V TJ P +150NC 3.0 3.2 MAX15041 toc20 2.8 VOUT = 3.3V VOUT = 2.5V 2.6 VOUT = 1.8V 2.4 VOUT = 1.2V VIN = 28V TJ P +150NC 3.0 2.8 VOUT = 1.2V 2.6 VOUT = 3.3V VOUT = 2.5V 2.4 VOUT = 1.8V 2.2 2.2 2.0 2.0 5 15 25 35 45 55 65 75 5 85 15 DEVICE POWER DISSIPATION vs. LOAD CURRENT VIN = 12V 45 55 65 75 85 3.0 VOUT = 3.3V VIN = 5V 2.
PAGE 8
Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches MAX15041 Pin Configuration LX LX LX BST TOP VIEW 12 11 10 9 PGND 13 PGND 14 MAX15041 IN 15 *EP 1 2 3 4 PGOOD EN COMP + VDD IN 16 8 I.C. 7 SGND 6 SS 5 FB TQFN *EXPOSED PAD, CONNECT TO SGND. Pin Description 8 PIN NAME 1 VDD 2 PGOOD 3 EN 4 COMP FUNCTION Internal LDO 5V Output. Supply input for the internal analog core. Bypass with a ceramic capacitor of at least 1µF to SGND.
PAGE 9
Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches ENABLE CONTROL AND THERMAL SHUTDOWN EN 5V LDO VDD UVLO COMPARATOR 4V MAX15041 VDD BIAS GENERATOR BST CURRENT-SENSE/CURRENT-LIMIT AMPLIFIER IN LX VOLTAGE REFERENCE N CONTROL LOGIC AND SINK LIMIT 0.65V LX VDD STRONG PREBIAS COMPARATOR 5µA N PWM COMPARATOR 0.606V PGND SS FB ERROR AMPLIFIER Σ OSCILLATOR COMP PGOOD SGND N 0.560V RISING, 0.
PAGE 10
MAX15041 Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches Detailed Description The MAX15041 is a high-efficiency, peak-currentmode, step-down DC-DC converter with integrated high-side (170mΩ, typ) and low-side (105mΩ, typ) power switches. The output voltage is set from 0.606V to 0.9 x VIN by using an adjustable, external resistive divider and can deliver up to 3A load current. The 4.
PAGE 11
Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches Internal LDO (VDD) The MAX15041 has an internal 5.1V (typ) LDO. VDD is externally compensated with a minimum 1µF, low-ESR ceramic capacitor. The VDD voltage is used to supply the low-side MOSFET driver, and to supply the internal control logic. When the input supply (IN) is below 4.5V, VDD is 50mV (typ) lower than IN.
PAGE 12
MAX15041 Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches Inductor Selection A larger inductor value results in reduced inductor ripple current, leading to a reduced output ripple voltage. However, a larger inductor value results in either a larger physical size or a higher series resistance (DCR) and a lower saturation current rating. Typically, inductor value is chosen to have current ripple equal to 30% of load current.
PAGE 13
Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches COMPENSATION RAMP VOUT Σ FB R1 MAX15041 POWER MODULATOR ERROR AMPLIFIER FEEDBACK DIVIDER OUTPUT FILTER AND LOAD VIN gMC COMP QHS VOUT L0 DCR CONTROL LOGIC R2 ROUT gMV RC PWM COMPARATOR *CCC IL QLS ESR RLOAD COUT CC VCOMP GMOD VOUT IL ROUT = AVEA/gMV *CCC IS OPTIONAL. REF NOTE: THE GMOD STAGE SHOWN ABOVE MODELS THE AVERAGE CURRENT OF THE INDUCTOR INJECTED INTO THE OUTPUT LOAD.
PAGE 14
MAX15041 Low-Cost, 3A, 4.
PAGE 15
Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches V 2π × fCO × COUT RC = OUT × VFB gMV × GMOD where VFB is equal to 0.606V. 3) Select C C . C C is determined by selecting the desired first system zero, fZ1, based on the desired phase margin. Typically, setting fZ1 below 1/5th of fCO provides sufficient phase margin.
PAGE 16
MAX15041 Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches 2) Place capacitors on VDD, IN, and SS as close as possible to the IC and the corresponding pin using direct traces. Keep the power ground plane (connected to PGND) and signal ground plane (connected to SGND) separate. PGND and SGND connect at only one common point near the input bypass capacitor return terminal.
PAGE 17
Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches PROCESS: BiCMOS For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
PAGE 18
MAX15041 Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches Revision History REVISION NUMBER REVISION DATE 0 7/09 Initial release 1 3/10 Revised General Description, Absolute Maximum Ratings, Electrical Characteristics, Applications Information, Figures 2 and 3.