General Description

The MAX1966/MAX1967 are voltage-mode pulse-width-

modulated (PWM), step-down DC-DC controllers that

are ideal for a variety of cost-sensitive applications.

They drive low-cost N-MOSFETs for both the high-side

switch and synchronous rectifier and require no external

Schottky power diode or current-sense resistor. Short-

circuit and current-limit protection is provided by sens-

ing the drain-to-source voltage on the low-side FET.

Both devices can supply outputs as low as 0.8V and are

well suited for DSP cores and other low-voltage logic.

The MAX1966 has an input range of 2.7V to 5.5V while

the MAX1967 has an input range of 2.7V to 28V. In

ultra-low-cost designs, the MAX1966/MAX1967 can

provide efficiency exceeding 90% and can achieve

95% efficiency with optimized component selection.

The MAX1966/MAX1967 operate at 100kHz and ac-

commodate aluminum electrolytic capacitors and pow-

dered-iron core magnetics in minimum-cost designs.

They also provide excellent performance with high-per-

formance surface-mount components. The MAX1966 is

available in a low-cost 8-pin SO package. The MAX1967

is available in a 10-pin µMAX package.

Applications

Features

o Cost-Optimized Design

o No Schottky Diode or Current-Sense Resistor

Required

o >95% Efficiency

o Low-Cost External Components

o All N-Channel FET Design

o 2.7V to 5.5V Input Range (MAX1966)

o 2.7V to 28V Input Range (MAX1967)

o 0.8V Feedback for Low-Voltage Outputs

o 100kHz Switching Frequency Accommodates

Low-Cost Components

o Thermal Shutdown

o Output Current-Limit and Short-Circuit Protection

Low-Cost Voltage-Mode PWM

Step-Down Controllers

________________________________________________________________ Maxim Integrated Products

1

GND

DL

VIN

1

2

8

7

DH

LX

COMP/EN

FB

BST

SO

TOP VIEW

3

4

6

5

MAX1966

Pin Configurations

Ordering Information

MAX1966

2.7V TO

5.5V INPUT

VIN

COMP/EN

GND

BST

DH

LX

DL

FB

Typical Operating Circuit

19-2286; Rev 1; 9/03

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

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

Pin Configurations continued at end of data sheet.

Set-Top Boxes

Graphic Card Supplies

xDSL Modems and

Routers

Cable Modems and

Routers

Telecom Power Supplies

Networking Power

Supplies

Termination Supplies

PART

TEMP RANGE

PIN-PACKAGE

MAX1966ESA

-40°C to +85°C

8 SO

MAX1967EUB

-40°C to +85°C

10 µMAX