General Description

The MAX15021 is a dual-output, pulse-width-modulated

(PWM), step-down DC-DC regulator with tracking (coin-

cident and ratiometric) and sequencing options. The

device operates from 2.5V to 5.5V and each output can

MAX15021 delivers up to 4A (regulator 1) and 2A (reg-

ulator 2) of output current. This device offers the ability

to adjust the switching frequency from 500kHz to 4MHz

and provides the capability of optimizing the design in

terms of size and performance.

The MAX15021 utilizes a voltage-mode control scheme

with external compensation to provide good noise

immunity and maximum flexibility in selecting inductor

values and capacitor types. The dual switching regula-

tors operate 180° out-of-phase, thereby reducing the

RMS input ripple current and thus the size of the input

bypass capacitor significantly.

The MAX15021 offers the ability to track (coincident or

ratiometric) or sequence during power-up and power-

down operation. When sequencing, it powers up glitch-

free into a prebiased output.

Additional features include an internal undervoltage

lockout with hysteresis and a digital soft-start/soft-stop

for glitch-free power-up and power-down. Protection

features include lossless cycle-by-cycle current limit,

hiccup-mode output short-circuit protection, and ther-

mal shutdown.

The MAX15021 is available in a space-saving, 5mm x

5mm, 28-pin TQFN-EP package and is specified for

operation from -40°C to +125°C temperature range.

Applications

RFID Reader Cards

Power-over-Ethernet (PoE) IP Phones

Automotive Multimedia

Multivoltage Supplies

Networking/Telecom

Features

♦ 2.5V to 5.5V Input-Voltage Range

♦ Dual-Output Synchronous Buck Regulators

♦ Integrated Switches for 4A and 2A Output

Currents

♦ 180° Out-Of-Phase Operation

♦ Lossless, Cycle-by-Cycle Current Sensing

♦ External Compensation for Maximum Flexibility

♦ Digital Soft-Start and Soft-Stop for Tracking

Applications

♦ Digital Soft-Start into a Prebiased Load for

Sequencing Applications

♦ Sequencing or Coincident/Ratiometric Tracking

♦ Programmable Switching Frequency from 500kHz

to 4MHz

♦ Thermal Shutdown and Hiccup-Mode Short-

Circuit Protection

♦ 20µA Shutdown Current

♦ 100% Maximum Duty Cycle

♦ Space-Saving (5mm x 5mm) 28-Pin TQFN

Package

MAX15021

Dual, 4A/2A, 4MHz, Step-Down DC-DC

Regulator with Tracking/Sequencing Capability

For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

MAX15021

TOP VIEW

26

27

25

24

10

9

11

12

1

+

2

EN2

4

*EP

*EP = EXPOSED PAD.

56

7

20

21

19

17

16

15

SGND

AVIN

COMP1

FB1

EN1

DVDD1

3

18

28

8

RT

PGND1

FB2

23

13

N.C.

COMP2

22

14

N.C.

N.C.

Pin Configuration

Ordering Information

19-4106; Rev 1; 8/12

PART

TEMP RANGE

PIN-PACKAGE

MAX15021ATI/V+

-40°C to +125°C

28 TQFN-EP*

+

Denotes a lead-free package.

*

EP = Exposed pad.

/V denotes an automotive qualified part.