General Description

The MAX15038 high-efficiency switching regulator

delivers up to 4A load current at output voltages from

making it ideal for on-board point-of-load and postregu-

lation applications. Total output error is less than ±1%

over load, line, and temperature ranges.

The MAX15038 features fixed-frequency PWM mode

operation with a switching frequency range of 500kHz

to 2MHz set by an external resistor. The MAX15038

provides the option of operating in a skip mode to

improve light-load efficiency. High-frequency operation

allows for an all-ceramic capacitor design. The high

operating frequency also allows for small-size external

components.

The low-resistance on-chip nMOS switches ensure high

efficiency at heavy loads while minimizing critical induc-

tances, making the layout a much simpler task with

respect to discrete solutions. Following a simple layout

and footprint ensures first-pass success in new designs.

The MAX15038 comes with a high bandwidth (28MHz)

voltage-error amplifier. The voltage-mode control archi-

tecture and the voltage-error amplifier permit a type III

compensation scheme to be utilized to achieve maxi-

mum loop bandwidth, up to 20% of the switching fre-

quency. High loop bandwidth provides fast transient

response, resulting in less required output capacitance

and allowing for all-ceramic-capacitor designs.

The MAX15038 provides two three-state logic inputs to

select one of nine preset output voltages. The preset

output voltages allow customers to achieve

±1% out-

put-voltage accuracy without using expensive 0.1%

resistors. In addition, the output voltage can be set to

any customer value by either using two external resis-

tors at the feedback with a 0.6V internal reference or

applying an external reference voltage to the REFIN

input. The MAX15038 offers programmable soft-start

time using one capacitor to reduce input inrush current.

Applications

Server Power Supplies

POLs

ASIC/CPU/DSP Core and I/O Voltages

DDR Power Supplies

Base-Station Power Supplies

Telecom and Networking Power Supplies

RAID Control Power Supplies

Features

o Continuous 4A Output Current Over Temperature

o ±1% Output Accuracy Over Load, Line, and

Temperature

o Soft-Start Reduces Inrush Supply Current

o 500kHz to 2MHz Adjustable Switching Frequency

o Compatible with Ceramic, Polymer, and

Electrolytic Output Capacitors

o Nine Preset and Adjustable Output Voltages

0.6V, 0.7V, 0.8V, 1.0V, 1.2V, 1.5V, 1.8V, 2.0V,

2.5V, and Adjustable

o Monotonic Startup for Safe-Start into Prebiased

Outputs

o Selectable Forced PWM or Skip Mode for Light

Load Efficiency

o Overcurrent and Overtemperature Protection

o Output Current Sink/Source Capable with Cycle-

by-Cycle Protection

o Open-Drain Power-Good Output

o Lead-Free, 4mm x 4mm, 24-Pin Thin QFN Package

4A, 2MHz Step-Down Regulator

with Integrated Switches

________________________________________________________________

Maxim Integrated Products

1

OUTPUT

1.8V, 4A

INPUT

2.9V TO 5.5V

BST

LX

OUT

IN

EN

CTL2

CTL1

PGND

FB

COMP

PWRGD

FREQ

REFIN

SS

GND

MODE

MAX15038

Typical Operating Circuit

Ordering Information

19-4320; Rev 1; 12/09

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.

PART

TEMP RANGE

PIN-PACKAGE

MAX15038ETG+

-40°C to +85°C

24 Thin QFN-EP*

+

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

*

EP = Exposed pad.

Pin Configuration appears at end of data sheet.

EVALUATION

KIT

AVAILABLE