General Description

The MAX15026 synchronous step-down controller oper-

ates from a 4.5V to 28V input voltage range and gener-

ates an adjustable output voltage from 85% of the input

voltage down to 0.6V while supporting loads up to 25A.

The device allows monotonic startup into a prebiased

bus without discharging the output and features adap-

tive internal digital soft-start.

The MAX15026 offers the ability to adjust the switching

frequency from 200kHz to 2MHz with an external resis-

tor. The MAX15026’s adaptive synchronous rectification

eliminates the need for an external freewheeling

Schottky diode. The device also utilizes the external

low-side MOSFET’s on-resistance as a current-sense

element, eliminating the need for a current-sense resis-

tor. This protects the DC-DC components from damage

during output overloaded conditions or output short-

circuit faults without requiring a current-sense resistor.

Hiccup-mode current limit reduces power dissipation

during short-circuit conditions. The MAX15026 includes

a power-good output and an enable input with precise

turn-on/turn-off threshold, which can be used for input

supply monitoring and for power sequencing.

Additional protection features include sink-mode cur-

rent limit and thermal shutdown.

Sink-mode current limit prevents reverse inductor cur-

rent from reaching dangerous levels when the device is

sinking current from the output.

The MAX15026 is available in a space-saving and ther-

mally enhanced 3mm x 3mm, 14-pin TDFN-EP pack-

age. The MAX15026 operates over the extended -40°C

to +85°C and automotive -40°C to +125°C temperature

ranges.

The MAX15026C is designed to provide additional mar-

gin for break-before-make times.

The MAX15026B/MAX15026C provide a soft-stop

feature to ramp down the output voltage at turn-off. The

soft-stop function is disabled in the MAX15026D.

Applications

Set-Top Boxes

LCD TV Secondary Supplies

Switches/Routers

Power Modules

DSP Power Supplies

Points-of-Load Regulators

Features

o 4.5V to 28V or 5V ±10% Input Supply Range

o Adjustable 200kHz to 2MHz Switching Frequency

o Ability to Start into a Prebiased Load

o Lossless, Cycle-by-Cycle Valley Mode Current

Limit with Adjustable, Temperature-Compensated

Threshold

o Sink-Mode Current-Limit Protection

o Adaptive Internal Digital Soft-Start

o ±1% Accurate Voltage Reference

o Internal Boost Diode

o Adaptive Synchronous Rectification Eliminates

External Freewheeling Schottky Diode

o Hiccup-Mode Short-Circuit Protection

o Thermal Shutdown

o Power-Good Output and Enable Input for Power

Sequencing

o ±5% Accurate Enable Input Threshold

o AEC-Q100 Qualified (MAX15026B)

Low-Cost, Small, 4.5V to 28V Wide Operating

Range, DC-DC Synchronous Buck Controller

________________________________________________________________

Maxim Integrated Products

1

2

4

5

*EP

13

11

10

LX

DL

DRV

EN

LIM

MAX15026

1

+

14

DH

IN

312

BST

PGOOD

69

GND

COMP

78

RT

FB

TDFN

(3mm x 3mm)

TOP VIEW

*EP = EXPOSED PAD.

Pin Configuration

Ordering Information

19-4108; Rev 4; 2/12

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

MAX15026BETD+

-40°C to +85°C

14 TDFN-EP*

MAX15026BETD/V+T

-40°C to +85°C

14 TDFN-EP*

MAX15026CETD+

-40°C to +85°C

14 TDFN-EP*

MAX15026BATD+

-40°C to +125°C

14 TDFN-EP*

MAX15026CATD+

-40°C to +125°C

14 TDFN-EP*

MAX15026DATD+

-40°C to +125°C

14 TDFN-EP*

+

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

*

EP = Exposed pad. T = Tape and reel.

/V denotes an automotive qualified part.

MAX15026C recommended for new designs.